"Breaking up" when in boost?

[DrX]

Engine is running nice and smooth idling or cruising, but when I get into boost it wants to break up badly. No misfires logged. Taking a look at this log I think this corresponds to intermittent AFR dips into the 9's on WO2AFR1 which I think is actually on bank 2. Not that I trust the accuracy of the dual LC1s, but it looks like there is a correlation here. A free air cal was done immediately prior to this log.

Motor has fresh coils, wires, plugs which definitely improved how it runs otherwise, but didn't help with this issue. Injectors are also new this year - ID1000 high Z. Current plugs are 8's gapped at .025. Any ideas? Take a look the spots where I give it some throttle and check out the WO2 traces. Didn't have this issue last year before the rebuild.

[joecar]

Hi DrX,

Not only does measured AFR dip excessively rich, but ignition timing pretty much goes to zero.

I can tell by DYNCYLAIR that the VE table is off, I think this is the problem, correcting the VE will get the AFR correct and ignition timing correct.

Can you log SPARKADV...?

[DrX]

I will get that(base spark) next log - deleted it to make room for state00. It was basically identical to run spark except in boost where I am pulling around 4* with A0010. Started tuning with VE scaled 50% and spark tables shifted accordingly from where I was last year. Didn't need scaling last year due to higher FP in boost with the dual FPR fuel system I was running. If VE is off now, one or both widebands are screwed up. To make it even more intersting, in today's log that wide band was dropping to 9 intermittently just cruising!

[DrX]

Here is a new log with A0010 zeroed out. Still get the "popping" from the exhaust in boost (actually sounds more like rapid fire shotgun blasts).

[joecar]

Spark timing is being pulled down alot during boost... do any of the EST_xxxx_DMA pids show the reason...?

[swingtan]

Any chance you have a loose plug lead? looks like the rich spikes occur even when cruising.

Simon.

[nevinsb]

Were the spark plug wires melted? It seems to be a re-occurring issue with mine.

[DrX]

The timing appears to be exactly what is being commanded by the High Octane table.

I replaced the plug wires without any improvement. No misfires logged even though it is obvious.

[DrX]

Looking at the rich spikes logged on WB1 which occur both cruising(more so at MAP values below 60 kPa) and always when into boost(multiple spikes at short intervals- .1 -.3 sec), what could cause this?

1. A bad wideband
2. A sticky injector
3. Intermittent loss of spark on 1 or more cylinders
Any others?

Now which is most likely and why would it get worse in boost?

Injectors, plugs, coils, wires are new. Plugs are gapped at .025"

[swingtan]

The sound described sounds very much like a misfire. If it's accompanied by a distinct lack of power, then I'd say it's dropping one or more cylinders. You may not get a misfire DTC though....

My thinking is that the ECM needs to know what a misfire is before it can detect one. In stock form, this is done on the stock tune with a CASE learn, the basics of which are that the ECM causes a deliberate misfire so it knows what it looks like on the crank angle sensor. If you go and change the motor and tune a lot, then the learnt misfire data is no longer valid. Unless a CASE relearn is performed, you may not detect a misfire. This is all theory by the way, I haven't really tested it.

I'd recheck the leads and plugs. You may need to perform and old time "plug reading" by pushing the motor to the point that sustained misses occur and then shuting off the motor straight away. Then pull the plugs to look for obvious differences.

I'd also do a "black" test on the leads. Run the car in the dark and look at the engine bay. In the dark, you'll be more likely to see any ignition spark leaks from the wires and coils.

0.025" may be a little narrow on the plug gaps and not allowing sufficient mixture between the electrodes to fire the mixture. Going along with this is the "8" reference for the plugs. Is that the heat range for them? If so, that's a pretty cold plug and may be causing issues. Most people I know that are running boost run a "6", or at the most a "7". You may be fouling the plugs as they are too cold to keep clean. A read of the plugs should tell the story, but I'd try a "6" heat range plug gapped at 0.035"

Simon.

[DrX]

There is definitely a loss of power when this occurs. Not that I keep my foot in the throttle very long. Sounds almost like http://www.youtube.com/watch?v=AEsFzeK0kB0 , just less rapid and a little louder. I have done a CASE relearn about once a week LOL. I have tried 9, 8 and 7 heat range plugs(NGK) since the rebuild. The 9's were first - I think it actually ran good on them until they became too fouled from a little street driving. 9's were recommended for my engine if running it to 20 psi. I lost the ground straps off a couple of 6's last year. The 6's are also a protruding style. I have been wondering about the plug gap as well. Although .025 is pretty well where the 7, 8 and 9's are gapped at out of the box. The 6's are around .035 out of the box.
http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3179.jpg

[DrX]

Just went out and checked my catch can and it is full after only 3-400 miles on the rebuilt engine - who knows how long it has been full. The can is connected between the driver's side fabricated, non-baffled valve cover and common inlet box for the blowers very near the inlet to the rotors for the drivers side supercharger. The PCV tube with orifice from the LS7 valley cover is spliced into the hose. If there is any pressure in the crankcase or high vacuum at the blower inlets under boost, it would likely force oil from the can into the blower. Not sure if the DS valve cover is the best arrangement for a LSX block but there was a clearance issue so the PCV tube had to be cut off the valley cover. I never saw this much oil in the can when I was using the valley cover PCV outlet. I never was too keen on the lack of baffles in these valve covers.

Fresh air intake side of the PCV. It is connected to the non-baffled right side valve cover and intake tube between one of the air filters and throttle bodies. Thought I would try no can on that side this time and found that there is only a light coating of oil in the intake tube. Last year I had a lot of oil blowing out that hose under boost, but half of the valve seals were crushed at that time. Still think I will put a can back on that side as well.

This might also explain why the #7 plug appeared to have a light coating of oil on it each time I changed the plugs. Oil could sit in the lower intake, run to the back and then into #7 as my garage floor is sloped that way for drainage.
http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3372.jpg

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_2068.jpg

[swingtan]

Ahh, well..... Given those pics I'd say the plugs are in the right heat range ;)

The catch can may be the culprit and feeding oil into the engine. It's an easy test to empty the catch can and do some tests, allowing for the fact that there may be some residual oil in the tubes and manifold. Might be an idea to disconnect it entirely just for a test.

Post some pics of the plugs if you can.

Simon

[ScarabEpic22]

I recently read some TBSS guys with stock or built engines have had issues with their blowers pulling oil through the catch can into the intake. Might be the case here, hope its as easy as moving the can to a different hose routing.

BTW I was wondering what a twin blown LSX looked like, but until I read this I didnt know it was twin maggie/whipples! Figured it was a pair of turbos. Must have a big cowl hood to fit that intake system too, looks good though!

[slows10]

Looking at the rich spikes logged on WB1 which occur both cruising(more so at MAP values below 60 kPa) and always when into boost(multiple spikes at short intervals- .1 -.3 sec), what could cause this?

1. A bad wideband
2. A sticky injector
3. Intermittent loss of spark on 1 or more cylinders
Any others?

Now which is most likely and why would it get worse in boost?

Injectors, plugs, coils, wires are new. Plugs are gapped at .025" When you figure out the extremly rich condition under boost, you will have fixed your misfire. Imo it is spark blowout. Did not look at your logs extensively but are you as rich as 9:1 - 10:1 during boost?

[Mr. P.]

Bad. Ass. :)

How the hell do you prevent belt slip?! I can't get a single TVS1900 to reliably hold a belt, let alone two Eatons LOL.

I had a missfire as you describe when I first installed my Paxton, could not get above 4500-rpm without mal-combustion; after helping a buddy install twin-72's on his truck we had the same thing, in both cases it was a spark plug with a cracked insulator, in fact both cases was the #7 plug because in the truck with the big-assed brake booster we got lazy with the wrenches and damaged the plugs during installation, mine actually had a visible crack on the insulator. BUT since you have switched plugs umpteen times that's probably not the issue!

A hint taught to me by Justin Gadberry - when logging, look at the NB O2 sensors as the miss/mal-combustion is happening; if you see one NB O2 sensor switching and the other 'flatline' then that tells you which side of the engine the missfire is on! Example - if the driver's O2 sensor goes pig-rich while the passenger sensor continues switching, then the missfire is on the driver's side!

OK I can help here, I think. Your PCV system needs a rethink, you are most likely boosting the crankcase.

Simple physics - high pressure always flows towards low pressure. Draw a diagram and label/visualize what parts of the induction are at high (atmospheric) pressure or low (vacuum) pressure, both at WOT and idle, and add arrows to map out actual flow of air (pressure) in the PCV circuit. You will find that the PCV circuit will stall or completely reverse at WOT (depending on if boost is present in the intake or not) and depending on how the PCV system is plumbed you will have oil in the intake charge stream while you are attempting to make maximum torque, this will lower the actual octane of fuel in the cylinder from 93 premium to around 80-ish = detonation = call to a flatbed wrecker.

This (diagram below) is the alternative I STRONGLY RECOMMEND, and the only way to completely eliminate any possible path for oil vapor to ever enter the intake manifold under power; and since a vent is present, the PCV hose from the intake manifold will not cause 'suction' in the crankcase at idle trying to suck in the gaskets, rather there will be a nice gentle breeze going from one side of the motor to the other side carrying steam & acid vapor out of the crankcase so you will still have the benefit of functioning PCV at part throttle and 4500-mile oil changes. The vent is necessary:
http://www.allensrodeophotos.com/Steve/PCV/Centri-Vent-V.gif

Using the Ford SVO PCV valve guarantees that under boost there is no pressure buildup in the crankcase to cause weeping at the main seals, ejecting of the dipstick, and/or pushing out pan gaskets at 7000-rpm; this is possible because the SVO PCV valve truly seals the boost from the crankcase. The FoMoCo SVO valve is the ONLY one that seals totally, I personally tried every PCV valve at Oreilly's one afternoon (but I hear rumor the OE Supra PCV valve seals too). At high-RPM the vented cap allows any blowby to easily escape the crankcase rather than push your gaskets out, or force oil out the front/rear main seals. This is a diagram of the change in pressures inside a motor under boosted operation:
http://www.allensrodeophotos.com/Steve/PCV/Centri-Vent-B.gif

My buddy and I modified my OEM oil fill cap into a vented one for 13-bucks; I bought the SVO PCV valve for 9-bucks; the 3/8" caps and longer vacuum line cost 5-bucks; we get the catch cans off scummit racing for just over 80-bucks. Proper PCV circuit for under $120 and I am sure a couple MacGyvers out there can probably do it for well under 100-bones.

If you want to do this setup and be totally emissions-legit you can use a second catch-can instead of a vent on the passenger-side of the motor, but you need to use a large capacity catch can like the Lingenfelter unit or similar (uses 5/8" or 3/4" hoses). You HAVE TO USE A SECOND CATCH CAN, whoever thought you could tee all the crankcase plumbing into one catch can has not realized that doing so just eliminates any draft/crossflow in the crankcase i.e. doing that stops all PCV action - check it for yourself, draw a diagram and you will see what I mean. Here is an emissions-compliant catch-can install which will still keep oil out of the intake, remember the second (fresh air) catch can must be high volume to handle the high-RPM blowby:
http://www.allensrodeophotos.com/Steve/PCV/Centri-CARB.gif

The diagramming portrays a centrifugal, because that is what I installed on my truck but I am sure you can follow the broad ideas here and apply to your project.

Mr. P. :)

[ScarabEpic22]

Interesting...Mr. P would this work just fine on a N/A truck too? Im about to buy a catch can, 23.5k without one on my TBSS and Im worried about it. Plus it makes tuning a little tricky, if Im sucking oil into the intake then my timings going to be off.

[slows10]

Check out RX products oil catch can pcv system. Specifically for boosted engines. It has multiple check valves. There are a few threads on the camaro5 forum. It is supposed to be the best system available. Many people are using it. There are some good pictures on that thread and diagrams. Its priced very reasonable also. They also have one for N/A engines.

[Mr. P.]

Interesting...Mr. P would this work just fine on a N/A truck too? Im about to buy a catch can, 23.5k without one on my TBSS and Im worried about it. Plus it makes tuning a little tricky, if Im sucking oil into the intake then my timings going to be off.

Remember, the whole key is high pressure seeks low pressure - diagram it out:

Diagram of OE PCV system operating at idle:
http://www.allensrodeophotos.com/Steve/PCV/OEM-idle.gif

Diagram of OE PCV system "operating" at WOT:
http://www.allensrodeophotos.com/Steve/PCV/OEM-WOT.gif

Either of these two solutions will solve the PCV oiling problem on a NA motor, while still providing functioning PCV:

http://www.allensrodeophotos.com/Steve/PCV/OEM-Fixed.gif

Because a NA/nitrous motor has no boost, there is no benefit to swapping in the SVO PCV valve, the OEM PCV elbow (it has no guts, it's not even a valve) is still adequate.

I have no idea what RX products sells (I have never seen their products) but yeah I would certainly check out all options.

Mr. P. :)

[swingtan]

Very good info Mr. P.

It might be that Drx is actually "vacuuming" his crank case with the PCV system he has. The inlet for his system is inside one air filter and the outlet is right next to the blower inlet. At full song, this may cause an excessive amount of air to flow through the crank case, drawing fluid oil into the catch can and filling it quickly. It might be better to have the exhaust side of the PCV system just behind the throttle body.

I'm not sure that this is the cause of the original problem though. The tip on using the NB O2's is an excellent one which I've used a number of times. I'm not sure if it'll help in this case though as when in boost, the commanded mixtures are very rich ( compared to stoich ) and the WB indicates a further rich spike. So the NB O2's may not show anything.

Drx, take some video of the miss and post it up. It may be help to hear it.

Simon.

[DrX]

Wow! Thanks for all the input. My Eureka moment did not pan out. Still have the same issue after draining and disconnecting the catch can from the blower inlet(which only sees vacuum so it cannot boost the crankcase). I also disconnected the fresh air side from the intake tube - it is connected to a second catch can that was vented to atmosphere for today's testing which put about 50 miles on the truck with plenty of hits to the throttle. If anything, it looks like the rich blips during cruise conditions have increased, but I do not feel anything while driving- seems to run very smooth when cruising. It is correct that the plugs have been changed umteen times. I also re-checked the plug wires again today.

I have not been able to hold the throttle down long enough to determine if there is any belt slip, but I am now running a 12 rib belt with custom pulleys on the twin Maggies. The pic above is last years 8 rib setup. I have to make a video so I can see what the new belt and tensioner are doing at high RPM. Might also mount the GoPro camera over the exhaust tips to see/hear what is going on there.

I was suprised that my injectors hit 90% DC today during a quick blip close to 7000 RPM (frame 10668). Thought I had more room than that on the ID 1000s. The bank 1/2 injector duty cycles are still not identical at all times during logging??? I would expect them to be so when running OL. Unless this is just an artifact of logging. Just did an injector balance test - there is only a noticeble RPM drop/stumble when 3,4,6 or 7 are disabled. Can't discern any change when 1,2,5 or 8 are disabled.

I haven't logged the narrow bands in the last few logs. If anything they appeared to show opposite of what the 2 widebands were doing.

[DrX]

Can't really hear the misfire/popping in this vid from a couple of weeks ago with the GoPro inside the car. I gave it a good amount of throttle just after the 30 sec mark(have to download the vid if you want to be able to rewind). Didn't seem to do it very bad that time. Actually it is not bad if I only go to 60-70% throttle or just a quick stab to WOT when the RPMs are already up. It is worst at WOT or at higher load.
http://i114.photobucket.com/albums/n241/TDOC2004/th_July62011.jpg (http://s114.photobucket.com/albums/n241/TDOC2004/?action=view&current=July62011.mp4)

This the old belt drive setup in action.

http://i114.photobucket.com/albums/n241/TDOC2004/th_BeltStretch.jpg (http://s114.photobucket.com/albums/n241/TDOC2004/?action=view&current=BeltStretch.mp4)

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_2037.jpg

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_2045.jpg

[DrX]

Can't really hear the popping in the vid I made today which is suprising considering how loud it is in the cab. There is a lot of other exhaust and tire noise at the same time though. Maybe the GoPro just doesn't pick it up.

http://i114.photobucket.com/albums/n241/TDOC2004/th_ExhaustSoundAug62011.jpg (http://s114.photobucket.com/albums/n241/TDOC2004/?action=view&current=ExhaustSoundAug62011.mp4)

I did notice when logging/driving with the cruise on at 50 kmh and 80 kmh that the rich spikes seem to correspond to throttle variations. At first I thought it was occuring also when the throttle was steady, but I did another log tonight and it seems to be related to throttle change. Although it is even occuring just coasting with the cruise off.

[DrX]

Checked some of the wiring today. Did find a short at the starter when I stuck my hand up there to check the CKP wiring. The foil insulation on the solenoid wire would ground out the hot battery cable if I barely moved anything in that area. I fixed that, but it didn't fix the problem. The truck actually has fairly good power, but it sounds like someone lit a string of firecrackers and threw it in my 4" exhaust tips.

I also pulled the bank 1 plugs(pic below). These have about 250 miles on them. Last 75 with a 50/50 mix of 93 pump and 114 race gas. The race gas seems to build up whitish deposits on the plugs. Will get to bank 2 tomorrow.

Seems I have a new issue now. There have been a couple of times when I shifted from drive to reverse and there was a "bang" when I started to move as if something was binding. It happened again today and now the motor will stall if I shift to reverse after driving. Oh, #1 is on the left.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3569.jpg

[swingtan]

Having one plug look significantly different to the rest is a cause for concern. #1 looks sooty, as if it has not been firing correctly.

[nevinsb]

Never thought about using a PCV valve on mine, I will have to give it a try. I didn't want to hook up to vacuum before the turbo because I didn't want oil in my MAF.

The audio on the Go-Pro camera I have is horrible. I have the non-HD model, and it doesn't matter how I put the case together (Like taking the lens cover off to get more sound), or either high/low volume, it either rattles, doesn't record audio, or is distorted.

[DrX]

Actually, I am glad to see just 1 cylinder different then the rest. Gives me something to work with. When I still had the Roadrunner installed every cylinder was different. We'll see what bank 2 looks like tomorrow.

[DrX]

Here's the bank 2 plugs, number 8 on the left. These are are pretty similar in colour. Also, don't forget that the first 200 miles on this set of plugs was with an overfull catch can. The last 50-75 miles with the catch can disconnected may have cleaned them up a bit. #1 looks like the prime suspect.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3577.jpg

[DrX]

Today I found that the torque converter bolts were rubbing on the dust cover of the trans, again - I had previously cut off part of the other side of the cover for the same reason.

What's more interesting is that when I was testing the injector circuits by individually momentarily grounding the pins at the PCM connector, I noticed that the throttle blades would twitch slightly whenever I activated an injector. This occurred with all 8 injectors. Looks like I have some electrical or electronic gremlins to work out.

Could not find anything specifically wrong with the circuitry for #1 cylinder.

[DrX]

Definitely got some house cleaning done but I still have the misfire/stutter and the logs are looking worse than ever. I guess my next test will be swapping the bank 1 & bank 2 injectors, which is a PIA on this setup.

[swingtan]

Did this just start up recently? Any chance you are getting bad / contaminated fuel ?

[DrX]

I have gone through a few tanks of fuel already. Seemed OK for the first 50-100 miles after re-installing the engine and running E10 94 octane on 9 heat range race plugs - until the plugs started to foul. I pretty well drained the tank before pouring in race fuel and installing new plugs as I was preparing for a dyno session that ended up getting cancelled. It idled better with the new plugs, but WOT was still an issue. Drained the race fuel and went back to E10 94 octane - continued to act up after that.

I was told that Bosch sensors will start reading 2.0 AFR units higher than actual if the mixture goes too rich?? I have dual LC1s installed. Not sure if this is correct or based on outdated info but I am not willing to set my commanded AFR in boost to 13.0 to find out. Even if they do tend to do this, is it not corrected by a free air calibration? I didn't think this was an issue as both widebands were reading about the same, other than the rich spikes on 1 side.

[JezzaB]

Try pulling about 10deg out of your WOT area for sh!ts and giggles and go for a run. So the 18deg would become 8deg

Also ive had no problems with TR6 plugs on 21psi

[DrX]

Try pulling about 10deg out of your WOT area for sh!ts and giggles and go for a run. So the 18deg would become 8deg

Also ive had no problems with TR6 plugs on 21psi

Already tried that. When I first fired up the new motor I actually did have very little advance in boost and it still ran great.

Couldn't remember if I removed the second fuel pressure regulator I had at the surge tank as part of the old dual pressure setup while installing the new motor or shortly after. If it was just after, then that may have been the point at which things changed. So today I disconnected the pump feed line from the bottom of the surge tank and the fuel only trickled out, even though the tank was full! So I spent today adding another line from the surge tank to the highest point on the factory tank. Hopefully this is the cure! Did some other tidying up as well while I had the tank out.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3606.jpg

[DrX]

Running much better now in boost. :grin:

O2s still look wonky in the logs, even more so with a new PCM. The right and left banks were much closer in the first log below which was with the old PCM. The 2nd log(0543) was made 30 min later with a new PCM. The rich spikes are still present.

I reconnected the catch cans today as well. During the 0542 log I collected about 2 oz of oil from the bank 1 valve cover. Bank 2 also had about 2 oz in the can but it has been connected for 70-100 miles.

[swingtan]

Do you have any NB O2 sensors in there? I wonder if the rich spikes are an issue with the WB that you have? Logging the NB O2 voltages might help to show if this is the case.

Simon

[DrX]

Do you have any NB O2 sensors in there? I wonder if the rich spikes are an issue with the WB that you have? Logging the NB O2 voltages might help to show if this is the case.

Simon

Yes, these logs include the NB 02s.

[swingtan]

Sorry, for some reason I missed them.....

looking at the NB data, it looks like the rich spikes are only in the WB signal, so it may be a bad connection / broken wire / short in the WB cabling that is causing that. There are a few spots where the NB voltage indicates aa "leaner than stoich" condition, but the WB shows rich spikes. The NB voltage, which should switch faster than the WB signal doesn't show the rich spike.

An interesting thing I see though, is that the NB and WB signals don't match banks. It looks like the bank 1 WB is actually connected to bank 2's exhaust and vice versa. If you are attempting to balance the banks at all, this is going to cause a few issues......

Simon

[DrX]

Yes it appeared to me also that the banks might be switched. With both widebands connected to the serial input of the V2, will the furthest or nearest to the V2 be designated as WB1?

I am not very confident that either of the widebands are accurate. But I have not been using the data from the one that exhibits the rich spikes. I am still concerned that neither the wide nor the narrow bands show any sort of balance between banks 1 &2.

[DrX]

The bank 1 & 2 widebands definitley are swapped. I left that as is for now and just swapped the sensors. The rich blips did not go to bank 2 , but now bank 1 cuts out after 2 min of operation and has to be reset by a restart. Bank 2 had a couple of blips to 5XX AFR. Bank 1 also shot up at the same time even though it had been stuck at 58 for a while.

[swingtan]

Yep, sounds like the WB is playing up. What brand is it ?

[DrX]

They are LC1s. Strange that they would both show a huge spike at the same time. Wouldn't be the first controller gone bad on me though. May be time to look at something different again.

[joecar]

Did you ever find out what caused #1 spark plug to look different...?

[DrX]

Did you ever find out what caused #1 spark plug to look different...?

Have not found anything specific yet. All circuits(injector, coil, spark plug leads) tested good. These plugs were in place during the time that the catch can was overfull though. Not sure if it had something to do with that or not. I swapped the plugs around and will check them again after I put a few miles on. Only thing I have not pulled out yet are the injectors, but I would expect that they were tested before I purchased them as they are supposed to be both flow and latency matched. I did check that each one "clicked" when the control circuit was momentarily grounded, and that the connectors were plugged into the correct injectors.

The apparent rich spikes in the logs were actually on bank 2. I had the serial connections swapped.

I also swapped the wideband sensors themselves as a test, but the erratic behaviour stayed on bank 2. I'm now getting an Error 8 from that controller. I did also relocate the sensors from just after the collectors to the header collectors. I performed heater recals and free air cals on both sensors when I swapped them. So the controller is telling me that the sensor that was working fine on the other controller is toast. The one that was appeared to be misbehaving on bank 2 now seems to operate correctly on bank 1.


Error 8 Sensor Timing error(typically a damaged sensor).
Likely cause:
1. Sensor overheating. (The Bosch LSU4.2 is rated to operate at a sensor housing temperature of < 900 degrees (measured at the bung) for maximum accuracyand control. When this operating temperature range is exceeded, the sensor can no longer be accurately controlled. )2. Sensor is damaged

Fix:
1. a. Perform sensor heater recalibration;
b. Move your sensor bung as far downstream as possible. Right before the cat, or 2-3 feet from the end of the tailpipe are good locations;
c. Add a heatsink to isolate the sensor from the pipe. The HBX-1 is an available accessory.2. Replace sensor.

[DrX]

Well I put around 200 miles on after swapping the plugs 1><3, 5><7 and similar on bank 2. I was in boost several times yesterday while passing on the highway and drove at 3000 RPM for the 60 mile trip home due to the 80E deciding to lose 3rd and 4th gears after being parked for a few hours. I did give it a .3 sec shot to 88% TPS after leaving the parking lot. It just stayed in 2nd after that.

The catch can was full when I got home. I pulled the plugs today and this is how they looked. The former # 3 which was now in #1 (far left)is now brown like the original #1. The plugs that were in 1, 3 and 7 all appear oily this time.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_3710.jpg

[joecar]

It is pulling in oil... when I saw that pic I was wondering why only on #1... now I'm wondering why #5 is not oily.

Which PCV system do you have (LS1 or LS6)...?

How quickly does the catchcan get full...?

Bummer about the trans.

Error 8: I find suggestion 2 works the best.

[DrX]

It is pulling in oil... when I saw that pic I was wondering why only on #1... now I'm wondering why #5 is not oily.

Which PCV system do you have (LS1 or LS6)...?

How quickly does the catchcan get full...?



PCV arrangement is using both valve covers. There are no baffles protecting the ports in these fabricated valve covers so it is very easy for oil to blow into the hose. The can was empty before the 120 mile drive on Saturday and full when I got home. Will have to modify these or find some new ones tall enough for the shaft mount rockers.

[joecar]

Using the out ports at the rear of both valve covers and the in port at the front of the RHS valve cover...? [ this is LS1 style ]

I have found that this arrangement pulls oil very quickly (when accelerating, oil pumps quickly to top of heads, and acceleration induced force pushes oil to rear of valve covers where it is promptly pulled into the intake manifold); I reversed the air flow so fresh air enters at the rear of both valve covers, drilled a hole in the oil cap and fitted a rubber grommet to hold the PCV valve, and capped the port at the front of the RHS valve cover; this works quite good at preventing oil being pulled in, even at WOT since there is a 1-2 kPa pressure drop across the throttle body, and the oil cap is the highest point on the valve cover; if you're clever, you can drill the oil cap part way thru thereby creating a baffle.

In your case, boost is pushing air in thru the front of the RHS valve cover, thru the block, and out of the rear of each valve cover (where oil accumulates during acceleration).


11692

[DrX]

There is no boost going to the valve cover. The RHS valve cover has been connected to either the cold air intake duct between the filter and the throttle body or to atmosphere, both via a catch can as I have seen a small amount of oil backing out this side as well. The LHS valve cover has been connected to a fitting at the inlet end of the blowers(after the throttle bodies) via a catch can. Hopefully vac is low there at WOT. It was probably high during my entire 60 mile, 3000 RPM trip the other day.

Here is a pic showing the location of the fittings on the valve covers.

http://i114.photobucket.com/albums/n241/TDOC2004/IMG_0317.jpg

[joecar]

Hmmm I see... which of the catchcans is filling up...?

[DrX]

Hmmm I see... which of the catchcans is filling up...?

The one on the left which is connected near the inlet end of the blowers is filling up. The fresh air side just has a small filter on a hose attached to the can. It is still getting a little oil though even with 0 vacuum pulling on that side.

[swingtan]

How much blow by do you get on this motor ? I wonder if the sump is pressurising enough to blow oil back up to the rocker gear as it tries to return to the sump? The other point is that as there are no baffles in the rocker covers, you may find that the outlet ports happen to be in the direct line of fire for one of the rocker oil holes. It may be that the oil is firing straight into the outlet and then getting sucked through by the blower. The more RPM's you run and the lower the manifold vacuum, the more oil would get into the catch can and then motor.

Simon