intermittent cutting out

F

FTC

Member
Joined
May 17, 2002
sup guys, actually been chasing this problem for a while now. seems to be intermittent and only on the highway at cruising speeds prob around 50-70ish. but the car will cut in and out today was the worst ive seen it in a while its more than a miss, closer to bucking or surging. up until today it would only do it once then be fine but today it surged in and out a couple of times in a row. a handful of times it happened going up an incline. anythign other than light accel ie. med to heavy throttle the car performs just fine. so far ive changed the coil pack/ign module with known good units, crank sensor, plugs and wires. car needed a tune up anyway do i did all of this within a couple of weeks. any ideas whats going on?? thanks
 
Possible bad cam sensor. Just went through this on a friends car. Would buck at light throttle but would run ok at heavy throttle.
 
Ok sounds like your definitely on the right track, I held a vac hose up to the cap and hear a very distinct ticking from the cam sensor cover. So just want to be sure that this is not normal and would indicate the sensor going bad. Tomorrow I will try and unplug it after starting then drive to work and see if there are any cut outs to be sure
 
On the drive to work today I unplugged the cam sensor and still was doing the same thing with the hesitation/cutting in and out so I think the cam sensor is ruled out. The only other thing I can think of is the ECM is no good, any ideas? Thanks
 
also i think i might have narrowed it down to it happening when the cars cold, cause in the afternoon when i drove home from work today it didnt do it. and im not too sure how it works but when driving to work in limp home mode with the cam sensor unplugged the motor lost its timing and started backfiring real bad and eventually died, i pulled over plugged the cam sensor back in and all was well aside from the cutting in and out. and i do have an off idle or "tip in" stumble. does that give any clues as to whats happening. thanks
 
ok took a log of it happening tonight, seems that the load and rpm spike harsh but yet the tps stays steady anyone know what would cause this??
 

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can i get that mail, too?

badguyv6 or FTC - i'm chasing the same exact problem, but mine is more consistent than ftc's. He's also gone further in chasing down the demon than i have. I've redone coil pack, wires, plugs. about to change injectors & chip (just gotta get time). My next guess was going to be the converter, but I don't think it's the converter because it still does it when I unplug the 4-pin connector on the driver side of the tranny (I was told this could be a clue to a converter that is beginning to fail).

Any way one of you could be a "goodguyv6" and send me that same reading material???

Mine basically feels like i'm accidently hitting the brake pedal every now and again while i'm driving at light throttle. If i open it up & let it scream it doesn't happen. I also have the same stumble on tip-in, but that's typically when the motor's cold / cool.

Thanks for any help you can provide.
 
So today checked a bunch of stuff
Cam sensor - all is well there cap and interruptor look fine
Iac - looked fine but cleaned with carb cleaner anyway
Crank sensor - all good
Changed plugs from autolite 23s to ur5s
Wires, module- all good didn't have a meter to check coil pack did a visual check on wires

After all that problem is still there and worse than ever. On the road test tried to push through the stumbling and got a flashing check engine light so that leads me to think the ECM. Tomorrow will check the PL connection and tidy it up, check pos and neg batt cables, check orange ECM wire which does have a anti theft device on it, wonder if that has anything to do with it? If all else fails will order a new ECM and report back.
 
You might want to unplug your ECM and look at the pins and the terminals. If you have corrosion in there, that could be all it is.

Spray them with some contact cleaner and carefully plug in and unplug each connector a few times to clean the contacts and do nothing else then test drive again.

If that helps, then add a light coating of dielectric grease to the pins with an acid brush. I had a similar problem a few years ago and this was my solution.

Bob
 
Thanks bob definitely will do, last night I pulled the ECM to clean up the powerlogger connections. But before plugging in I was planning to clean up the contacts.
 
check the ignition module wires.Had a problem like that before.With car at idle ,move up and down back and fowar the module wires and look for any changes.
 
Changed the ECM and no dice, now I'm getting frustrated with this thing. Battery cables appear to be ok. Tomorrow will check ECM and ign module connections. Now is happening everytime the car warms up, sure as **** about 5-10 minutes into a road test it will start breaking up and popping anything above extremely light throttle. When it's cold everything seems to be working fine
 
Stock or reman MAF? Give it a rap and see if it stumbles at idle. Ign modual? Is the stuff inside gooey when it is warm. If it is stock it may be on it's way out. One of these two is my guess. Hope you find it.
 
Make sure your positive battery cable is not against the passenger's side header, also check all your ground wires, some on the back of the motor to the firewall. It sounds like it's electrical in nature, good luck.

Chuck
 
Maybe the fuel pump? Might as well change the plug wires as that is easy and could be the problem.
 
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