Help me. Car is stalling

[dcstang67]

First off the car is a 2002 Cavalier 2.4L 5 speed manual with custom turbo setup and HO intake with 56mm throttle body. I am running a modified 2 bar program designed for the supercharger. When I come to a stop The car bogs down and stalls. I have noticed that when it does this I noticed that the timing goes to 30+ degrees. None of the spark tables are calling for this much spark. The car has been doing this for a long time so I have been running it in open loop. I really want the car to run in closed loop. Because of the temperature changes, when in open loop when it gets colder out the car runs really rich.

[redhotjamedjimi]

i had this problem when i didnt have my injectors tuned. but it shouldnt run rich in open once it has warmed up. maybe you killed your o2 sensor from boost ive gone thourhg a couple before hptuners came my way. modified supercharger program? are you still running the stock timing for you engine? for idle it says your timing at 40kpa is 21 shouldnt that number be lower? . my 2 cents

plus a supercharged engine needs more advance cause of the load a supercharger puts on the crank opposed to a turbo so all your low end numbers a lil out of whack?

[dcstang67]

I just put in both new GM o2 sensors in last week. Its not the sensors. I am thinking it may be the IAC motor. The car surges at idle also

[dcstang67]

I just noticed another spark table under torque management called Retard vs. RPM vs. % Torque Reduction. I noticed that this table is different from the supercharger file to the stock file. I am posting up a stock file for you to compare to.

[gman4dx266]

FYI: Torque Management isnt whats making it stall and crap out when you stop.

[redhotjamedjimi]

once my battery was dying from lack of alternator and it will run rich and stall.

or a vacuum leak. with that new intake/tb may be giving to much air? with a high advance it will kill an idle.

even brake booster probs? you stop hit the brakes sucks more vacuum and messes up idle? bigger tb less vacuum?

trying to help out im learning myself.

[redhotjamedjimi]

hey i jsut notice u have you pe multi by rpm all out of whack running lean? the higher the leaner the lower the richer and you have it lower at idle speeds making it richer. so maybe your prob...

its probably advancing cause of your richness at your sensor so its like a crazy octance and higher tables.

i think.

[dcstang67]

FYI: Torque Management isnt whats making it stall and crap out when you stop.

So then what is causing it?

[imphat0260]

Im almost wondering if your TPS is crapping out.... I just watched that log and there are a few spots where the RPM is going up and the TPS is still reading 0........ I have had this happen a few times on customers cars and on the wifes... May have a dead spot in it.......

[dcstang67]

trust me. when the tps is reading 0 I am completely off the throttle. the car will surge up to try and save itself from stalling.

[dcstang67]

The car doesnt do this when in open loop. Even when I had forced open loop all the time it never did this. Today I changed the iac between three that I have in stock and it did it with every one. I also changed my bov from the knockoff RFL to a bosch style eclipse bypass valve. Neither of these made a difference. There has to be something in my tune that is causing this.

[redhotjamedjimi]

do you have a skinny or way big exhaust?>

[dcstang67]

I have 2.5" mandrel exhaust with magnaflow high flow cat and magnaflow muffler

[imphat0260]

Correct me if Im wronge, but I wanna say I remember somthing about a post on JBO about when you got your original tune... Didn't the guy tuning it on the dyno start using randon numbers for the injector and then modify the VE table to compensate for it?? not sure if this is quite it, but I remember something along those lines.....

[dcstang67]

Yess thats what happened, I am running a different tune now. Also I tried doing the math for the injectors and it never worked out right so I just kept changing the IC to whatever made the car run right and a 14.7 afr on my wideband.

[Enthusiast]

Im having the same problem sometimes with my car but I have an 02 eco. I really think its the IAC. if not my fuel pump may be bad since I run on E before a fill up. hopefully you can get it fixed.

[imphat0260]

post both the stock/modified tunes... Also, what injectors are you running again and what fuel psi??? I wont have a chance to look untill tomorrow.. (will be driving over night)

[dcstang67]

I am running 48# bosch injectors running at 55psi at idle and 62psi at wot. I will include the stock tune and the current tune and also a new logging session. The car will bog down below the set idle when I press in the clutch sometimes stalling and sometimes not. Also with the car sitting if i rev it up a little it will do the same thing. the stock tune is
(02CavalierManualSuperchargerReflash.hpt) and the other ones with dates are the current tune and log from today.

[dcstang67]

I noticed that when the fuel trim table changes from 16 to 19 the timing drops from 12.5 to -0.5 degrees and then back up to 23 degrees you can see this at frame 29800, and again at frame 31500. Im sure there are other spots in the log where it does this. Just look for when I drop the speed down to 0 mph.

[imphat0260]

I just briefly looked at the Files.. (doing the family thing)...2 things that are sticking out to me currently are your injector constant and your VE tables..(specifically your idle one)... That thing has more ups and downs than a worn out elevator..... Have you asked the guy who tuned it why he did what he did??? Was it a reputable company, or just a shop with a dyno trying to make money???