"Breaking up" when in boost?

[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.


This the old belt drive setup in action.

[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.



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.

[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.

[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.