Car wants to stall when stopped in gear

[rdx]

Hey guys, I've been chasing this one for sometime now, I need some advice here :)

My 96 Formula sometimes has like a miss when totally stopped but only when it is in gear, it usually occurs only after the car has warmed up..

I have done a lot of stuff on my car like:

-New injectors
-New fuel filter
-New intake hoses and gaskets (Made sure not to have vaccum leaks anywhere)
-Blocked the EGR off
-New spark plugs
-New spark plug wires with heat shields
-New TPS
-Throttle body bypass
-Cleaned up the Throttle body
-Cleaned up the MAF with MAF cleaner
-New bank 2 cat
-New starter

I also recently swapped my 4L60e since the original one was fried, I got another tranny out of a 95 Camaro, both trannies have the PWM pump and I just needed to swap the tailhouse and VSS sensor to get it bolted and running.. but I didn't swap the wiring harness and solenoids.. I also used my original torque converter.

The miss and stalling issue started pretty soon after the tranny swap, but I'm not really sure if I'm looking here into an engine issue or tranny issue, maybe the opti? maybe an o2 sensor (I did got a couple of codes of the bank 2 sensor but never got them again after I replaced the cat) Maybe the TCC solenoid? Or maybe I should have swapped the whole wiring harness and solenoids out of my 96 4L60e? What are your thoughts?

The only codes I have in the PCM now are P0336 Crankshaft Position Sensor and P0400/P0403 both for blocking the EGR

[rdx]

Anyone? This issue is pissing me off!! :jest:

[zmm95]

If you were an m6 I would think stalling in gear, hmm that sounds like an issue with the clutch not disengauging enough which leads me to belive this is a torque converter issue. Is the ccar stalling or missing when stopped in gear? Misses in every single car I've worked on have always been ignition related

[rdx]

If you were an m6 I would think stalling in gear, hmm that sounds like an issue with the clutch not disengauging enough which leads me to belive this is a torque converter issue. Is the ccar stalling or missing when stopped in gear? Misses in every single car I've worked on have always been ignition related

Yeah it makes sense to think about the torque converter, mainly because of the recent swap. Well it doesn't always stall, it seems to me like a miss because the rpms go up and down and when it gets too bad, it sometimes stalls.. I don't get any missfire codes since I have a P0336 Crankshaft Position Sensor code that prevents my car from detecting missfires..

Today I unplugged O2 sensor #1 of bank 2, which is the one I was getting codes for and the car ran great the whole day, it didn't stall nor even seem to have the miss anymore not even once, even when it reached operating temperatures so I'm pretty confident now that the problem only occurs during closed loop operation and it's very likely a failed O2, I will be replacing it soon and see how it goes.

[zmm95]

I wouldove never even thought of an o2.. good work, let me know how it goes with replacement... my next guess was going to be your IAC failing or your tps was out of adjustment

[Fixxer99TA]

Honestly, I had the same problem awhile back that seemed like it solved itself.. "Seemed" would be the keyword.... Now, before you just replace it this problem could have many causes, problem is its tough to diag a car you cant actually see/hook a scanner to.

I also hate to be the guy that throws it out there first, but after I replaced the opti it cured itself. It went from the idling low/almost stalling on a regular basis symptom you describe around town to sputtering and completely cutting out every 30 seconds after a few hard track runs on my way home. The car would restart no issue, but then give it 30 seconds to a minute or so and dead again... and eventually it got to the point of no restart also... Thankfully I was already IN my driveway when it got to that point. Not saying start there, but that seemed to be my problem. My problem must have had something to do with the optical sensors in the opti, and then flogging the crap out of it at the track just made it say "Ok, Ive had enough". Havent had that problem reoccur since.

[rdx]

Actually I do know I need to replace my opti soon, I know the prev owner of the car had installed and cheap ass opti from ebay.. However I think that the O2 went with the cat so it is just making things worse and that's probably why unplugging the sensor helps the car to keep running, the opti is my next upgrade, you don't have an idea how many issues I've had to fix since I bought the car :) but I'll get there!

[black heartbeat]

check for resistance from the wires of the Crankshaft Position Sensor to the pcm, and check for frayed wires. The stalling issue when it gets warm almost sound like the insulation separating and the crank sensor not giving a signal back to the pcm will make your engine cut out. You can a code that is likely to cause drivability issues. It's worth looking into. Not saying its not a torque converter issue or something else but start with what you know is going wrong

[black heartbeat]

also i saw you have a new tps, do you have a stock tb?

[rdx]

check for resistance from the wires of the Crankshaft Position Sensor to the pcm, and check for frayed wires. The stalling issue when it gets warm almost sound like the insulation separating and the crank sensor not giving a signal back to the pcm will make your engine cut out. You can a code that is likely to cause drivability issues. It's worth looking into. Not saying its not a torque converter issue or something else but start with what you know is going wrong

hey thanks! I checked for continuity on the wires of crank sensor sometime ago, and the prev owner also changed the sensor, I've read that code can get set because of the cam sensor within the opti too since the PCM compares both signals..

About the torque converter, I think that's pretty much discarded already since the car is working fine with the O2 unplugged. BTW I tried to change the O2 sensor today and damn there's no room for anything there, I couldn't get the sensor out! Will have to try again..

[LT1RUNNER]

Dang i was gona tell you all that. HAHA. There you go best info and it didn't cost you anything.

[rdx]

So I've been driven my car with the o2 unplugged for a while now and never had the issue again, I had to buy an o2 sensor socket to get the old one out and today I was fiinally able to install the new one, the issue is gone, the old sensor looks pretty bad, I will change the other ones too

[rdx]

Giving an update on this one.. The o2 sensor did make a big difference and helped the car to keep running but yesterday I installed my new optispark and the car runs A LOT better, the rpms are much more stable now, the old opti was about to crap on me :) but the o2 was making things even worse. Car runs like a champ now! And by the way, the new opti got rid off the P0336 crank position sensor code too