1999 3.4 V6 Rough Running?
Beachmom
02-22-2005, 08:32 AM
Has anyone experienced the following problem: After my van has been running for awhile, it will start "bucking"/"jerking". It kind of acts like it is having a hard time moving forward. I have taken it to a local auto shop, and they couldn't find anything wrong. I took it to a transmission shop and they had to drive it about 70 miles before it did it, but their computer did show anything wrong with the transmission. I then took it to the local Olds dealer, and they couldn't get it to do it and their computer didn't show anything either. They said next time it acts up to just bring it to them right away. Well it did it this weekend when we were coming home from a trip on a Sunday, (of course they aren't open on Sun.) My husband drove it all over town yesterday to get it to act up, but it didn't do it. Does anyone have any idea where this problem may be coming from?
Thanks,
Cheryl
Thanks,
Cheryl
94 Jimmy
02-25-2005, 01:00 PM
Cheryl
Sometimes you just have to wait for it to quit, then tow it in and have it fixed...or...try shotgunning it(not that way), changing suspected parts and see if it helps, this can be expensive if your wrong and don't do the work yourself.
The engine has a crankshaft sensor which is the master timer for everything that happens in the engine, ignition, ignition timing, fuel injection, everything important. It is the one sensor that does not have a limp home work around in the computer, if it fails (as mine did in a 89 Olds 98) you don't go anywhere. But if it gets a little bad it can really foul up the engine (as it did on my 88 Plymouth Horizon).
These sensors are Hall Effect devices which are solid state switches that are sensitive to magnetic fields. Like all solid state devices they are sensitive to heat, they can fail totally as in my 89 Olds or just lose gain as they did in my 88 Ply. When they lose gain, the signal that tells the computer about the position of the crankshaft and everything else in the engine is delayed, which retards the ignition, fuel injectors ect. All in all, the engne loses power or misfires. My 88 Ply had a top speed of 25MPH floored, and its exhaust manifold was cherry red hot, because thats where most of the gas was being burned. Is this your problem, maybe, that's why we call it shotgunning. No real target just hit everything.
If your engine is losing power, and misfiring at idle or low speed, when warm, that would be the component I'd change first, they run about $30 at Rockauto.com, and mine was about $100 to install. If it's only a little bad perhaps it isn't setting a code in the computer yet. I took the part to the mechanic and paid to have him install it. Mechanics double or triple the cost of parts they buy from the same store you do.
Another possibility is the ignition module which lies below the ignition coils. If it were misfiring one of the coils that would cause a loss of power and jerky operation.
Or perhaps you'd just rather wait. Sooner or later it'll get bad enough to set a code, but to keep paying shops to say "Welp, I just don't know" is a waste.
Read the forums, and service manuals. Get to know your vehicle and save lots of $$, be informed and take the kids to Disneyland with the money you save.
Let us know what you find.
See ya
94
Sometimes you just have to wait for it to quit, then tow it in and have it fixed...or...try shotgunning it(not that way), changing suspected parts and see if it helps, this can be expensive if your wrong and don't do the work yourself.
The engine has a crankshaft sensor which is the master timer for everything that happens in the engine, ignition, ignition timing, fuel injection, everything important. It is the one sensor that does not have a limp home work around in the computer, if it fails (as mine did in a 89 Olds 98) you don't go anywhere. But if it gets a little bad it can really foul up the engine (as it did on my 88 Plymouth Horizon).
These sensors are Hall Effect devices which are solid state switches that are sensitive to magnetic fields. Like all solid state devices they are sensitive to heat, they can fail totally as in my 89 Olds or just lose gain as they did in my 88 Ply. When they lose gain, the signal that tells the computer about the position of the crankshaft and everything else in the engine is delayed, which retards the ignition, fuel injectors ect. All in all, the engne loses power or misfires. My 88 Ply had a top speed of 25MPH floored, and its exhaust manifold was cherry red hot, because thats where most of the gas was being burned. Is this your problem, maybe, that's why we call it shotgunning. No real target just hit everything.
If your engine is losing power, and misfiring at idle or low speed, when warm, that would be the component I'd change first, they run about $30 at Rockauto.com, and mine was about $100 to install. If it's only a little bad perhaps it isn't setting a code in the computer yet. I took the part to the mechanic and paid to have him install it. Mechanics double or triple the cost of parts they buy from the same store you do.
Another possibility is the ignition module which lies below the ignition coils. If it were misfiring one of the coils that would cause a loss of power and jerky operation.
Or perhaps you'd just rather wait. Sooner or later it'll get bad enough to set a code, but to keep paying shops to say "Welp, I just don't know" is a waste.
Read the forums, and service manuals. Get to know your vehicle and save lots of $$, be informed and take the kids to Disneyland with the money you save.
Let us know what you find.
See ya
94
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