3800 Stumbling/surging on any sort of load

[digitaloutsider]

Well, I'm posting this here because it also applies to 3800 Regals. At first, this was a sporadic problem, but it's definitely gotten worse. On idle, the engine will stumble a little bit, and when you rev it up, it stumbles and surges BAD. The car is nearing an undrivable state. There's no power at all at any speed. The plugs are about 4k old. Numerous tanks of gas. What the hell could be the problem? ICM/Coilpacks?

[maybe2fast]

ICM/Coilpacks?

 

I think you are barking up the right tree

[glock19]

I've seen bad plug wires cause this as well. Maybe one was damaged when you replaced the plugs 4k ago.

 

Glock

[3pt1lumina]

Lazy O2 sensor or bad plug wire, maybe ICM.

 

If it was coilpacks would it act up all of the time?? Sorry, I'm new to DIS ignitions.

[DiscoStudd]

I'd suspect the crank sensor, as they're known to go out fairly often on the L27 (and it won't throw a code when its bad, either.) You'll have to yank the crank pulley to replace it, and get a special tool to align the new sensor properly on the timing cover.

 

Have you changed the fuel filter lately? They're in a really "fun" spot on the H-Bodies (up under the exhaust tunnel close to the engine...)

[jdcutty]

I second the crank sensor. I had a mid 80s 3.0 that had a badly aligned crank sensor and it ran like shit. jumping, hisitating, you name it. It eventually slung the belt at about 70mph. No joy in that ride

[Brian P]

I'm going to 2nd an ignition problem. Check the wires first (my moms car had a problem like that, wires were arcing at the coils)

[dsgrntld187]

Definately check the wires. This happened to my Cutlass, and it ended up just being one wire.

[94CutlassSLCoupe]

I agree sounds like coil packs or plug wires

[digitaloutsider]

Okay, it isn't the wires. Still could be the coils/ICM. I haven't changed those yet. It's running so rich, the exhaust smells like just gasoline, nothing else.

[dsgrntld187]

Really sounds like the coils/ICM to me

[digitaloutsider]

The Bonneville is back in comission. I swapped the coilpacks from my GP and voila! Thanks, guys!

[99RegalGS]

Glad to hear you got your car running better again Shaun.

 

and get a special tool to align the new sensor properly on the timing cover.

Actually the newer 3800 crank sensors do not need that alignment tool. Not sure when they switched to it, but I'm assuing when GM went to the fast start C3 ignition on the 3800's. IIRC that was in 88' for the LN3

 

I wish I had a pic of the newer Crank sensors, but there is a dowel pin in the front cover and the sensor simply get's put onto the dowl pin, no alighnment nessary.