Problem Tunning For New Cam

[shakinlm7]

Hey guys I was just hopping someone might be able to spot something I've missed in my tune. I'm tunning according to the Auto VE Tutorial and I had everything damn good before I put in a cam. I've logged and updated my the VE table 5-6 times now and its still not right. below 4k rpm is pretty good but above it the numbers are all over. Around 4800 rpm it losses power big time! Its a 2000 GMC seirra with a 2002 OS, 5.3 lm7, 2001 z06 cam (204/211 525/525 116 advanced 4 degree's using a roller master double chain timing gear set, catback exhaust, gutted cats, Efans, Under-drive pulleys, 160 tstat, stock intake, and a lingenfelter oil pump.

Any insight would be appreciated!:master: lol
Mike

[5.7ute]

You are not setting a P0102 or P0103 code so your maf is not failing. This is preventing you from going into SD mode & allowing the auto VE process to work.
Set C2903 to 1. Make sure you start with an unmolested VE table as the one you have now will be dangerously lean over 4000 RPM. Do a small log & check with the DTC tab that a trouble code has been set.

[shakinlm7]

It's throwing P0102. I cut all the wires to my MAf but 2 for the IAT

[shakinlm7]

Today I took 8 hours to travel what normally takes me 4 hours. I did a LOT of logging and updating to my tune. When I first start logging My BEN-lc1 map the numbers fluctuate more, but after I get a good amount of counts in each cell the map will read .99-1.01 across the grid up to 4800rpm. anything above 4800 is inconsistant.... I noticed the afr drops down as low as 10.0 No mater how much VE tunning I do it still does the same thing. I'm starting to wonder if I advanced my cam right. It has NO power after it hits 4800 rpm I Finlay spun it up to 5600rpm since I wasn't running lean and I'm not getting any NR but the data I logged didn't do any good once applied to my VE table. I tried it several times.

[5.7ute]

It can take a while to get the VE table right. Especially if you are not filtering transients out.
That log you posted up I downloaded again & it is still not showing a maf fail code. Do you have a later log you can post up?

[joecar]

You need beter resolution in your log... you are using 36 channels which means your time resolution is 0.2s... remove some pids until you get to 24 channels (which gives 0.1s resolution)...

Also, your LC-1 doesn't appear to be working right...?

VE table looks like it's going bad...

[shakinlm7]

The logging I did yesterday was with 24 channels. I'm on vacation using a family members dial up service. I will to try and find a wifi connection in town so I can download the updated stuff. the only changes I did to the tune were high and low octane spark and the VE table. I smoothed it out a little and changed the values from 4800 up so they are equal to the value in 4800 for each row, for the most part it looks the same and performs about the same..... what do you mean by the VE table looks like its going bad? I started over with the stock VE table like recommended and could you explain why the LC1 looks like its not working right?

Thanks again for you input guys!

[joecar]

It seems to me your LC-1 doesn't appear to respond to the commanded AFR... I would have expected it to follow the commanded AFR more... I'll take another look at your log when I get home tonite (...sorry, I was in a bit of a rush this morning... :redface:).

The VE table doesn't look right, but I'll take another look.

Also, as 5.7ute said, I don't see a MAF DTC in the log... but you're satisified that it is getting one.

Cheers
Joe
:cheers:

[shakinlm7]

click (shift+f8 ) when your on the dtc page and you'll see P0102 several times in my history. I must have cleared the codes before saving it or something....

[shakinlm7]

Here's the latest log and tune

[shakinlm7]

Maybe it would be easier for someone to look at this pic and tell me if I have my timing chain set up to run the cam 4* advanced. I don't have a picture of exactly how its set up but its pretty close.
The crank timing gear is spun so the key is one notch to the left of tdc when your looking at the pic. Instead of how it is in the pic where it is spun two notches to the left of dtc. The dots on both sprocket teeth are lined up perfectly and I know it is not 180* out.

[shakinlm7]

Does anyone else have any advice?

[Chalky]

Did you look @ IFR, B4001? Yours is flatlined.

[joecar]

Maybe it would be easier for someone to look at this pic and tell me if I have my timing chain set up to run the cam 4* advanced. I don't have a picture of exactly how its set up but its pretty close.
The crank timing gear is spun so the key is one notch to the left of tdc when your looking at the pic. Instead of how it is in the pic where it is spun two notches to the left of dtc. The dots on both sprocket teeth are lined up perfectly and I know it is not 180* out.I'm no expert, but wouldn't that retard the cam instead of advance it (if the dots line up)...?

[Chalky]

Joe:

I use the same timing gear setup. His cam looks OK. Moving the crank gear to the right advances the cam. Usually, every keyway is 2*.

[joecar]

Joe:

I use the same timing gear setup. His cam looks OK. Moving the crank gear to the right advances the cam. Usually, every keyway is 2*.Oh I see... :idea:

let's see if I understand it:
the crank sprocket is installed to the right (when crank itself is at TDC),
then when sprocket dots line up, crank is before TDC, thereby cam is advanced...

Thanks for the education... :cheers:

[Chalky]

Oh I see... :idea:

let's see if I understand it:
the crank sprocket is installed to the right (when crank itself is at TDC),
then when sprocket dots line up, crank is before TDC, thereby cam is advanced...

Thanks for the education... :cheers:

I cheated and had to go back and look at some pics. The gears sets make it easy though by showing +/- 2-4-6 degrees.

[shakinlm7]

Did you look @ IFR, B4001? Yours is flatlined.
Thats how it is on the stock tune for my truck and I am still using the stock injectors, rail, and fuel pump. From what I see on the VE table it looks like it uses less fuel at higher RPM than it does in the mid range so that might have something to do with it.

[shakinlm7]

I found a picture of a ls1 timing chain that showed advance numbers on the key ways and on the sprocket teeth. The first time I started my truck after the cam swap the timing chain was as pictured above. It ran REALLY bad! I would give it 100% throttle and it would barely run. Thats why I think I might have it wrong......

[Chalky]

My guess is that cannot be right. I am no auhtority but every IFR table iI have seen is not a fixed value. Did you see if there was a similar tun in the repository?

When I looked at you log file, your idle is at around 45 KPA and your OlCF table goes to 13 or so @ 55 KPA. You also run into big KR like 8* KR at pretty much anything off idle when adding throttle and your timing tables are not that agressive.

Could anyone have alterd your tun prior to you getting your vehicle?

how big are the injectors? If you know, you can run them through one of the available spreadsheets and change the values.

[Chalky]

Whether you have the cam in +4 or -4 degrees, it should still run and idle ok depending on cam. 4* +/- is in the realm of possibilities assuming cam is ground straight up. Are you sure the dots were lined up on teh timing gears?

Have you ruled out a vacuum leak? The runner gaskets on the LS motors can slip.

If truck is in OLSD, let it warm up, log AFR commanded and actual, timing #1 cyl and KR. Also capture Man Pressure in KPA.

[Chalky]

You are right. I just found a tun file for a 2002 5.3 and the IFR table is a fixed value.

??

[dfe1]

You are right. I just found a tun file for a 2002 5.3 and the IFR table is a fixed value.

??
The reason that the IFR tables for Corvettes, Camaros, Firebirds and some other vehicles have scaled vallues, is that these vehicles have a "returnless" fuel system that does not include a pressure regulator that is referenced to manifold pressure. On the other hand, most trucks have such a pressure regulator so there's no need to create an electronic reference to manifold pressure-- the regulator has a direct reference. Similarly, if you were to install a manifold pressure-referenced regulator on an engine not originally so equipped, you would change the IFR table to a fixed value.

[Chalky]

OK. just an idea after looking at VE table. have you tried a stock VE table and just adding 15-20% to all values and then trying it again?



If that is a valid VE table based on AutoVE? Max values @ 1600 RPM?

I would think that these would be signs of an overly advanced cam.

There are some builders/tuners on the forum. Howard @ Redline Motorsports might be better able to help.

Good luck. I hope you get it running to your satisfaction.

[Chalky]

The reason that the IFR tables for Corvettes, Camaros, Firebirds and some other vehicles have scaled vallues, is that these vehicles have a "returnless" fuel system that does not include a pressure regulator that is referenced to manifold pressure. On the other hand, most trucks have such a pressure regulator so there's no need to create an electronic reference to manifold pressure-- the regulator has a direct reference. Similarly, if you were to install a manifold pressure-referenced regulator on an engine not originally so equipped, you would change the IFR table to a fixed value.

Thanks for the info. I didn't know GM was still using a regulator. I assumed all were just returnless systems like Vets/F-Bodies.

can you think of anything that would cause his VE table to peak @ 1600 RPM outside of an overly advanced cam? The VE max numbers seem OK, just peaking way to early. With an overly advanced cam would come an increase in compression which could account for the KR so early.

[dfe1]

Thanks for the info. I didn't know GM was still using a regulator. I assumed all were just returnless systems like Vets/F-Bodies.

can you think of anything that would cause his VE table to peak @ 1600 RPM outside of an overly advanced cam? The VE max numbers seem OK, just peaking way to early. With an overly advanced cam would come an increase in compression which could account for the KR so early. I don't think this is a tuning issue. The cam isn't radical enough to require any changes to a base tun file for the engine to start and run decently. Tuning will certainly optimize performance, but if extensive changes are required, or if air/fuel ratio is whacked in some areas, other things are going wrong. Judging by the VE table, that's the case-- the spine at 1600 is more than a little strange. You may be right in thinking that the cam isn't installed correctly. For what it's worth, any time I've had to work over a VE or timing table to the point that it looked wrong, in order to get an engine to run decently, there's been a mechanical issue. Once the mechanical issue was corrected, the engine would run fine with tables that looked right.

As a general rule, it's best to make one major change at a time. It would be easier to troubleshoot if the truck still had a functional mass air sensor. That way, you could load an LS6 cal and if the engine had the same problem, tuning would obviously not be the issue. Also, if the OS was changed from a 2000 to a 2002, you have to question whether the conversion was done properly. Again, if the MAF was functional, you could reload the original 2000 tun file, cut and paste the LS6 VE tables and see if the problem still existed.

[shakinlm7]

I had tried starting over with a fresh 2000 os off of the tun repository. I ran it through the autoVE tutorial, logged a couple runs updating the VE table every time and it did the same thing as its doing now. I'm going to give roller master a call today and hopefully they can help me verify whether its installed right or wrong.
Thanks Again Guys!
Happy holidays!

[shakinlm7]

I finally found some info on rollmaster timing chain installation!! :) Looks like I actually retarded my cam. Hopefully it will work out!

[5.7ute]

I dont want to sound like a smart ass here but a simple check with a degree wheel would of found this issue upon install.

[shakinlm7]

I don't want to sound like a smart ass but you definitely just sounded like a smart ass :D

[dfe1]

Actually, I don't mind sounding like a smart-ass, but he'd also need a dial indicator to check cam timing. As for shakinlm7, you sound like a smart-ass too. Maybe we should start a club.

[shakinlm7]

I will NOT be associated with any form of Smart-Ass-Ism!:secret:

[dfe1]

I will NOT be associated with any form of Smart-Ass-Ism!:secret:
Too late.

[shakinlm7]

Post whoring yes, but no Smart-Ass-Ism:notacrook:

[joecar]

lol... smart-ass-ism... :muahaha:I'll add that to my spell checker dictionary... keep up the good work... :cheers:

[dfe1]

lol... smart-ass-ism... :muahaha:I'll add that to my spell checker dictionary... keep up the good work... :cheers: The question now becomes, when someone practices smart-assism, does that make him or her a smart-assist or a smart-assismist?? Seems like a fitting question to be answered by the keeper of lost bolts.

[Biggsy]

The question now becomes, when someone practices smart-assism, does that make him or her a smart-assist or a smart-assismist?? Seems like a fitting question to be answered by the keeper of lost bolts.

Smart artists maybe