Still stalling when I come to a stop and step on the clutch

[synister 1]

Your log shows an overlean condition at idle causing idle timing to fluxuate and over compensate.Add fuel to the ve at idle limit your idle timing.This should cure your problem.Also if the t body is larger than factory slow the throttle follower this will help you when you push in the clutch

[redhotjamedjimi]

Thats crazy good answer A, for a junior tuner.

could add fuel be add fuel psi also? which fluxates that good ol constant u love.

[dcstang67]

It is still stalling. Today I swapped out my crank sensor to see if that was causing it and it didnt change a thing. I have also changed out my cam sensor, O2 sensors, IAC, TPS, ICM, Plugs, Plug Wires, Coils, Coil housing. Now I am thinking about throwing in some different injectors to rule them out. The only thing I can think of is when I put in the new motor I put on a new Timing chain, head gasket, and bearings just to freshen it up, what I am thinking is maybe the timing chain is one tooth off. I dont know how bad or good it would run if this happened, but it runs great except for the stalling when coming to a stop. My fuel trims are all within a good range from -3 to 3. Here is my latest log. There is a good one at frame 3471.

[redhotjamedjimi]

maybe your throttle body is too hardcore for your cam and just cant get that idle vacuum. OR spark is too high.

[dcstang67]

the TB was on the other engine and it ran fine before.

[redhotjamedjimi]

same ve tables idle spark what else would affect that?

Whats a throttle follower?

[dcstang67]

I swapped out my injectors today for some 48# accell injectors and the problem still exsists. Now I am leaning towards the timing chain. I think when I put the engine together the chain had to be off by one tooth. I have shecked and changed everything else. Check out my advance at idle. it seems to climb and fall and when it is climbing thats when I notice the engine rpms will drop slightly until the advance drops down again. I have dropped the base idle timing down to 16 and it still does the same thing.

[redhotjamedjimi]

idk completely about you problem but i have some more questions.

Are you running 1or 2 bar? cause your idle vac is in between.

Why dont u get a 165 stat so that nasty 198 never affects anything.

Did u change all your transmission pulses etc stock when u switched to the 2002 supercharged dingy.

ever try going back to one bar with stock see if its not the software?

Would the supercharged 2002 have any diff sensors?

I noticed today that my launch spark is at 0 so in low rpms it sets my advance at 0 and lags til its over 2k rpm.
Im guessing that should be advance. It was before and it ran better.

[dcstang67]

I knocking on wood as I say this. I think I have fixed the problem. I lowered my Idle Base Timing down to 14*. I also set the timing in the main spark tables to 14* around the Idle area. Check out the file and the log.

[PDXGTP]

This is an interesting post here fellas.
A friend has a 98 Grand Am with the 2.4 (L4) 5speed and he bolted on a supercharger.
I have figured out how to tune the car, its not finished but its really good so far, we will do more later this weekend but...

This Grand Am has the same problem you guys are talking about.
it doesn't always stall but frequently. I drove it the other day for 30 mnutes and it was golden but it still stalls at random.
The only thing I noticed is his timing idle base and low and hi octane tables are all different at idle where he's idling at (30 kpa map @ 1000 rpm) but the timing advance in the scanner is bouncing from 22* to 27* and even 29* at times. The idle bounce is nominal.

I will watch this post and try the things you are talking about.

The idle base timing was 24* where he's idling at 30 kpa map so I set the the timing to 23* from 40 to 75 kpa thinking that when it stumbles the timing will be similliar. That table used to drop off to 6* or something like that buy the time it got to 100 kpa at the right side of that field..
Then the high & low octane tables I was talking about, I also set those to 24* from 600 to 1000 rpm and across from 20 kpa map to 40 kpa map and it hasen't seem to make any difference, the timing still bounces in the scanner while idling.

I made some Airflow/Main VE/ idle adjustments but they haven't helped.
I'm pretty stumped and was wondering if there are some more data fields that we cannot see that Chris could unlock?

I think I'll try some of the more drastic timing drops like synister suggested because it can't hurt.

I normally tune L67's, L36's & L32's but I have to admitt, I am enjoying this motor... if only I can get past this nonsense stumble & stalling thing.

later,

[imphat0260]

I'm pretty stumped and was wondering if there are some more data fields that we cannot see that Chris could unlock?

http://www.hptuners.com/forum/showthread.php?t=20255

[PDXGTP]

Hello,
I thought I'd report back in on this topic because appearently we got it figred out and it was tune related.
The proble was all in the timing, basically we had to do a timing tune.
We got the idle nailed first then realized that the second you give the car some throttle position your out of the Base Idle timing table....
- then the two other fields that provide data were not the same timing and the timing could jump back & fourth.
and once the rpm dropped below the idle set rpm... the negitive timing in the top right of the timing table e.g. in the timing table for low octane,
- once the rpms dropped into 800 or 600 rpms the field around 65,70 & 75 MAP kpa the timing was going into the negitive numbers and the PCM was using those numbers.
- This also effected the engine when launching, once the rpms dopped so did the timing.
After correcting this the car hasen't stalled since. it used to be a hallange to use reverse.. who knows.. its a GM thing.. but that was the tried & true test. now the car isn't bogging and weak during launch too. its much better.
The guy that owns the car said all the forum guys have told him stuff about needing a 2000 PCM, 2 bar map etc and we are making progress and tuning this car with no problem.
The thing is, without this car having a MAF its all hard work geting it tuned. Now we are working on the VE-low rpm single & dbl fire tables transitioning inot the Main VE-High rpm but were learning and having fun with this car.

I could do some before & after screen catures if anyone needs them for brain food but the lesson learned is timing & VE that jumps from one field in the program to another.

Later.