What could this problem be?

[Pace 1989]

My car sputters, and pops when under heavy (not WOT) acceleration.
Also, just cruising on the highway it will jerk, almost like a misfire, but no backfire. It's pretty bad. Even if the cruise control is on.
Here's what I've done:
-ran on direct scan, and I can find nothing. The LV8 goes up, timing goes a little down, pulsewith doesn't change too much, rpm jumps down a little, and it doesn't matter where the tps is at. But nothing showing what is going wrong first.
-I usually run the Translator and extender, swapped it out and put in an oem maf & chip, still the same problem.
-tested coilpack, it's good 12.4k ohms at each terminal.
On the highway it can be pretty bad, like a mule kicking the cowl panel. Please help!

Ken

 

[topfuel]

I had a bad cam sensor once, it caused symptoms similiar to yours. Start the engine then unplug the cam sensor, if the problem goes away then the cam sensor is bad.
good luck...

 

[jastrckl]

Just because the ohms measured good on the coilback doesn't mean it's necessarily good. It just means that it's not guaranteed dead. It could still be failing under load or heat. When my ignition module went out, it was somehow cutting the ecm on and off and DS would show some empty frames. Something may be resetting your ECM. The cam sensor is a good bet, or maybe MAF. Tap the maf with the engine idling and see if it stumbles, if it does, it's bad. I have a suspicion it's the MAF.

 

[Quick6'n'-K.C.]

i too would say coil pack and or module-

if it idles and revs fine in neutral, but any type of load in gear and it pops, then swap em out together to see if the problem goes away-
BW

 

[1BADDAM]

Friggin contagious

Ken,

Let us (me) know what you find, mine too did it this morning, must be contagious. Haven't driven the car to work in over six months, get in and its sputtering down the road. Ran fine the night before when I went to get gas in it.

Mine does it under even a light load, sputtering like its running out of gas. Idle seemed to be higher than normal on cold start up, no sputter when you rap the throttle in park or neutral. Checked the fuel up to the injectors, all is fine. Mine has a new coil pack from Caspers, can't have more than 2k on it.

 

[Pace 1989]

Found it!

-swapped the ecm, no change.
-swapped the maf, & chip no change.
-checked the coilpack, and it ohmed alright.
-swapped the module & coilpack, and bingo no more problem.

-I'm not sure if it was the coilpack or the module. I know coilpacks can ohm within range and still be bad. It works now, no more popping or bucking.
-hope this helps someone.



Ken

 

[MSDGN]

That's why Caspers Coil Pack/Module Tester is an invaluable tool...
you can use it to test the coil pack/module under varying levels of load...

 

[Pace 1989]

Bad news

Bad news. Was getting on the highway today, stomped on it and when it got to about 17lbs of boost it did it again. I never floored it before. It never did it again, and doesn't seem to be a problem under partial load or light throttle.
Just wanted to keep you guys updated.

Ken

 

[JoeNational]

Question is this only happening when your in OD? becuase it sounds very similar to the tcc solenoid being bad because of everything else you tested and did. becuase my car feels like it is going over bumps (sputtering type of thing) and change coil pack and still have the problem.

 

[BJM]

Have you had the coil pack and module off the car for any reason? I bet your ground from the module, through the bracket, throught second bracket to the manifold is bad. My car did the exact same thing (mule kicking thing) about month after swapping the unit and after the air cooled down a bit. Sanded down the brackets at each joint and problem was fixed.

 

[Pace 1989]

-I'll try cleaning up the brackets. When I swapped out the module/coilpack I noticed one of the nuts holding it down on the driver's side was gone, and the other was loose. I replaced them both w/the correct type nut/washer.
-I sort of suspect a wire, when I went to check the coilpack one didn't seem to click as good as the others and I took a pair of pliers and squeezed it until I could feel a good click. I have MSD wires, and they are less than a year and a half old. I'll check that wire.
-I don't think it's the torque converter sol. I just had the tranny rebuilt about 1500 mi ago and they used all new parts. This problem just started happening about 300 mi ago. Also when it does the "kicking" thing on the highway it's intermittent, and direct scan shows that the TCC is on, and stays on. It's also sputtering when I get on it in lower gears. Wouldn't that suggest that it is not the TCC sol?(I'm guessing here)
-I'll try these things this weekend and I'll keep you updated, thank all of you for all your help!!!!


Ken

 

[BJM]

If I am right, its the entire ignition shutting off and on randomly from losing the ground, exactly like mine. I forgot to mention I used dielectric grease on the freshly sanded areas to keep them from corroding.