I have 92 Camaro 305TBI with 700r. When you put the car in gear it dies. I have checked for vaccum leaks lines brake booster intake ect no leaks or crimped lines.Replaced the TCC solenoid and torque converter. I have no codes when scanned. I have replaced the ECM, MAP sensor, TPS, IAC, EGR and O2. I have good fuel pressure and rebuilt the TBI. And did a complete tune up. Car doesnt miss or hesitate and has plenty of power when your driving it.The only way I can keep the car from dieing is to turn up the idle screw until the car idles at 1500 rpms and then it drops to 700 rpms in gear. I have even ran a can of seafoam through the intake and one through Throttle body to see if this would help. I tried unhooking the CAT and still same old problem. My only other thought is the park neutral switch. Does anyone else know what it could be.

 

could be the TQ converter.... has it been replaced? my friend had his done and they stuck a truck one in with a lower stall and it would stall when put in gear but if it had gas it was fine. ur converter could be bad.

 

I replaced it brand new

 

will it idle in gear like at a red light, or do you give it gas then too?

 

no it will only idle in gear with the idle screw turned up if not it will die if you dont hold one foot on the brake or one on the gas

 

so what if you were to set the idle high, then put it in gear and have the e-brake on. While it is in gear, lower the idle to 500 RPM. Then take it out of gear and see where it idles.

I am no expert, but it would be interesting to see. I have a 5-spd car so I have no idea where the idle in park is supposed to be on those cars.

 

if you turn the idle down the car will die

 

Couple of thoughts

P/N Switch tells ECM to raise idle RPM by about 50 RPM at a most.
You should get ALDL cable & WinALDL to see what IAC is doing when it is in park vs. when in drive.
It is also possible that you have incorrect replacement EGR valve. Disconnect and plug vacuum line to make sure that it is not contributing to your stall.


//RF

 

I have disconnected all vaccum lines except to the map to c what would happen same problem.Ive kinda ruled out the p/n switch because i have to idle the car up to 1500 rpms to keep it from dieing.My thoughts is maybe the intake is stopped up under the egr. what i cant figure out is when the car is cold there is no problem once it warms up it dies in gear now what isnt opened or closed when the car is cold?

 

Roy

In a typical TBI setup, when engine is very cold (before ECM enters close Loop), CTS < 50 degrees C, ECM commands fuel mixture rich - about 13.5:1. Cold engines need rich mixture to to warm up quickly and idle half decently. Also, ECM makes no mixture correction based on O2 readings since NBO must be at 600F before its readings can be considered valid. That's why newer cars employ heated NBO vs. non heated once used in original third gen applications.
Once ECM sees CTS > 50 (about 2 minutes of engine running time) it will attempt to transition to a close loop operation (CL) based on NBO output. ECM will attempt to adjust injector pulse width to attain 14.7:1. If you have a vacuum leak due to EGR passage being open or other source fuel mixture will lean out and ECM will try to rich it up by drowning your engine with fuel. If you have ALDL cable and WinALDL you will be able to see what ECM is trying to do.

Check all gaskets - sometimes TB to intake manifold are known to blow though. Get an EGR block off plate - just to see if you have vacuum leak there.

I hope this helps.

//RF

 

I dont have a ALDL cable and IM not familiar with them.Oh and buy the way the car does seem to run rich.Today I did take the car to someone my friend has been tring to get me to take it to. HE scanned it with his dianostic tool and found no codes.He looked at the tps and map to see what they were doing and said they were fine.He tried to access the IAC but said he could not get any feed back from it and that the ecm wouldnt let him in to see what was going on.So he saw I had a new IAC and checked all 4 wire to the ecm to make sure they were all good and they checked out.He then told me to take the prom chip to the chevy dealer and see if it was the one for the car or has someone put in the wrong one. I dont know since I just got the car with this problem.The ecm has been replaced as did i try a new one but not the prom. I did unplug the IAC and the car idled up to about 2500 rpms. And im not sure how to check the IAC. I did do a ohms check on it and my old one and got the same readings I dont know if they are bad or good.
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OH and the vaccum leaks I have doubled checked every where for them but cant find any.And the car runs perfect in park. Also give me a quick lesson on this ALDL cable since all i have been using is a paper clip for a dianostic tool

 

Roy
1) Take a look at your ECM - on its cover should be part number and broadcast code (BCC). Broadcast code is a calibration information used by your ECM to control engine. BCC should be a four letter (how funny) alpha code. The same BCC should be on label covering UV window of your EPROM. Without knowing ECM part number your friend with a scanner could not configure his scanner correctly.

2) WinALDL cable is used to interface between ECM and a laptop running a special program (WinALDL, Tuner Pro, others) to get engine performance data. A lappy offers great deal of advantage over scanner since its allows to record and playback recorded data. WinALDL cable can be ordered for about $60 and software free. Just make sure that your ECM is covered under supported types!

3) IAC is a controlled vacuum leak. ECM controls it, but it does not know when its fully closed. You can reset it by following instructions here:
https://www.thirdgen.org/tpimod2
It is possible that you have an incorrect IAC valve - there are minor differences between different applications. As a result IAC is always leaking hence high idle and engine stalls when load is applied.

//RF

 

I reset the IAC the car ran good around 800rpms I tried putting it in gear and and the rpms dropped to 450 then back up to 1000 and then died.I dont believe this is wrong IAC I tried the old one and it had the same effect.I went to the dealer and the prom is correct but the computer is a aftermarket and they couldn't tell me if it was the right one. Also when when we checked the car the guys dianostic computer said the car was running in limp mode. Why would it read this? What compants tell the ecm to adust the IAC? I am assumming the map tps does what else determines how the IAC pulses? Could the speed sensor play apart in this because mine doesnt work?

 

could the fuel pressure regulator have to much pressure and cause this thing to be running rich? could the cts be playing a part in this?

 

Roy

Without having a chance to look at the data logs we are just guessing... However, the chances of too much Fuel Pressure are low, but the opposite is more common. Stock TBI runs between 11 and 13 PSI. You can verify this by tapping at the inlet port with a T or by removing fuel filter and inserting a T there. There is no FP test port in TBI system.

A limp mode could be caused by a dead CTS. CTS operation can be verified by back probing yellow wire with a DVM.

//RF

 

I checked the CTS and its good. Before I checked the fuel press and I read about 11.5 to 12 psi I know thats good. Also I verified the car had the correct ecm and prom. The car seems to be running rich thats why I was wondering if the regulator could cause this but it is new as well and I have ruled out the CTS. What I dont understand is why the car dies when it warms up and you put it in gear.If its cold its fine. You have to let it warm up for about 10 mins before it will die.The car doesnt have a miss it runs good wide open up hill in the level or in park. When the car starts to die I hear the injectors slow down and its like I hear the car suck for air and it jerks and dies. ANd then smells flooded.Today I did find a wire on the passenger side that is green and is in a loom by its self it has a end with a melted connector.It was hanging down by the starter and knock sensor any Ideas what this is for.And as far as the limp mode I dont understand how the car would run so good down the road in limp mode I always thought this was just to get you home and that the car would barely run.I am almost at the point of taking the TBI off and go to a carb. I know its got be something simple but I cant figure out what I'm missing other than cash I keep spending on trial and error parts.