Stalling issue
Thread Starter
4th Gear
Joined: Jun 2019
Posts: 4
Likes: 0
From: Washington
Stalling issue
I have a 1984 Oldsmobile cutlass and swapped a ls1 from a 97 c5 corvette in it. After warming up, if i drive for about 5 mins and I come to a stop light or keep my foot off the gas for a few seconds it stalls out but if I keep my foot slightly on the gas full throttle comes back after about 30 seconds but very rough. After stalling once or twice within a 20 minute window I notice the voltage getting stronger and the car starts running fine for the rest of the day. Any suggestions? A buddy of mine was saying it may be the IAC but I wanna make sure before I start playing guessing games
Burning Brakes
Joined: Dec 2017
Posts: 755
Likes: 272
When you swapped the motor, did you also use the PCM that was with it? Did you retain the capability to pull codes?
If you did retain the LS computer system, something like a sensor would certainly throw a code to point you in the right direction. If not, you’ll need to do quite a bit more diagnosis. In my experience, sensors don’t “typically” fail and then start working normally again. But weirder things have happened.
If you’re noticing fluctuations in voltage, I’d start with the charging system.
If you did retain the LS computer system, something like a sensor would certainly throw a code to point you in the right direction. If not, you’ll need to do quite a bit more diagnosis. In my experience, sensors don’t “typically” fail and then start working normally again. But weirder things have happened.
If you’re noticing fluctuations in voltage, I’d start with the charging system.
Last edited by wscott62893; Jun 4, 2019 at 05:52 AM.
Drifting
Joined: Jul 2015
Posts: 1,844
Likes: 375
From: San Jose, CA
Are you using a Corvette throttle body?
There are LS1s with mechanical cable throttle bodies, and LS1s with electronically actuated throttle bodies. The corvette is electronic. Being electronic, as far as I understand (and I have been wrong before, heh) there is no IAC, because the throttle actuator cracks the throttle plate slightly open to act as idle air control.
Now to me this sounds like an electrical issue. You are going to need to start with pulling any codes and then hooking up scan tool(s) to see what the computer is reading. Otherwise we're just guessing. If I was randomly guessing I'd say maybe the MAF is off, but that's just a random guess. Let's do it intelligently.
There are LS1s with mechanical cable throttle bodies, and LS1s with electronically actuated throttle bodies. The corvette is electronic. Being electronic, as far as I understand (and I have been wrong before, heh) there is no IAC, because the throttle actuator cracks the throttle plate slightly open to act as idle air control.
Now to me this sounds like an electrical issue. You are going to need to start with pulling any codes and then hooking up scan tool(s) to see what the computer is reading. Otherwise we're just guessing. If I was randomly guessing I'd say maybe the MAF is off, but that's just a random guess. Let's do it intelligently.
Racer
Joined: Sep 2011
Posts: 310
Likes: 38
Kind of sounds like it could be fuel too, loading up at idle. Any smoke as you rev it? I think youd have to diagnose more, I wouldn't just start throwing sensors at it.
Had an LS3 swap car that loaded up at idle like that, and you could smell it was rich at idle.
Had an LS3 swap car that loaded up at idle like that, and you could smell it was rich at idle.
Last edited by jrob56; Jun 6, 2019 at 12:03 PM.
