4L80e makes car die in Drive only!
Thread Starter
Staging Lane
Joined: Apr 2015
Posts: 63
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From: Kansas
4L80e makes car die in Drive only! I need some serious help! Have a 2000 4L80e swapped fbody controlled by the factory harness and ecm. Just did heads and cam. And went to get the car tuned. now the car sputters and dies the second you stick it in drive or any forward gear! If you give it throttle the car does fine it can make a full pull with converter locking and unlocking like it should but the second you come to a stop it sputters and dies. I've read about tcc dragging but haven't seen my same symptoms on other threads I need help!
Swapped heads and cam, now the car dies in gear at idle...how are you connecting this to the torque converter? It's got a cable throttle, turn the set screw up a bit and see if it helps. If so, take it back to the tooner, reset the screw to its original position and have them dial in idle airflow.
Thread Starter
Staging Lane
Joined: Apr 2015
Posts: 63
Likes: 0
From: Kansas
He has already tried that! my tunner has 7.5 hours on the idle problem alone. He commanded 1500 Rpms via the tune and stuck it in reverse and it did fine, went to neutrual fine and the second he stuck it in drive it didn't even sputter it plain out died. He commanded more than double air flow counts and it sputtered a little bit longer and still died. And HP tuners idle tables are the same in reverse and drive and it does fine in reverse. That's why I'm leaning more mechanical.
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Staging Lane
Joined: Apr 2015
Posts: 63
Likes: 0
From: Kansas
no it like sputters does not lung or jump it's like the motor is being dragged down in rpm. Sometimes it will idle for 5-10 secs before it sputters and some time it will do it the second you put it in drive. And if you give it throttle it will take off and drive fine but you come to a light or a stop it will sputter and die.
If it doesn't try to roll forward as the engine dies, then it's likely not the converter. The torque has to be going somewhere; if it isn't going to the wheels and you're confident it isn't idle air, then look at the other two components...spark and fuel. Have you checked grounds?
Thread Starter
Staging Lane
Joined: Apr 2015
Posts: 63
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From: Kansas
Only grounds that I have touched are the ones on the rear driver head to take the heads off. Was reading some say depending on the year there is a ground on the rear passenger head but I don't remember taking one off. I only remember taking the rear driver head grounds off.
Thread Starter
Staging Lane
Joined: Apr 2015
Posts: 63
Likes: 0
From: Kansas
No. So unbolted the converter from the flex plate and removed the main harness plug from the trans and the car was doing the same thing when you stick in drive it was dying and also was dying in park. And after a few attempts it started 800rpm surging when the trans wasn't hooked up
Yep, sounds like either tune, or mech., like a bad IAC or TPS. The factory ECU's must get some info from the shifter itself-I have only used the Holley stuff, doing it yourself you get a first hand look at what affects what.
I would prob ck idle vac, do a comp ck (was it a large cam) and find another tuner.
I would prob ck idle vac, do a comp ck (was it a large cam) and find another tuner.