PLEASE HELP ASAP!

I installed a 180* stat today, and immediately following, as I was travelling down the highway, if I try to accelerate too much, the engine sounds like it is backfiring... not loud, only enough to hear it. It only does it sometimes. It will also hesitate or lurch forward, or stutter when accelerating.

I'm no mechanic, but I can't figure out how my changing the stat could've caused this...

PLEASE HELP. She is all I've got to get around... Any Ideas?!


I have to teach classes tonight, and we're taking my girlfriend'* car.
I'll be back on later tonight.

I'm thinking you might have accidentally left a vacuum line disconnected or maybe knocked one loose. Check out the lines and connectors carefully. Sometimes when they get older they become brittle and just bumping a connector can induce a crack. While you are looking for those, also look for any loose or dangling electrical connectors (although most of those would set a code if undone).

To me it sounds a lot like an ignition problem, possibly plugs/wires/coils. Not that changing your stat would cause this of course, but it just could be coincidental.

Definitely check your vac lines first as Bill said. You'd be surprised how much one bad vacuum line could screw up your engine'* performance.

Thank you so much. Here'* an update... Now the car is stuck in front of my girlfriend'* house. It turns over but won't start. My dad is worried that I might have jumped time somehow, from the backfires that were occurring before, and then we both had a thought...

A little over a year ago, I had the coil pack / power thingy (pack, i think? technical huh?) underneath it go bad. I had almost identical symptoms as the ones I am having now. This is not uncommon. My dad'* SSEi had the same problem happen when he had it. When we replaced the power pack, the wires looked pretty crappy, good enough, but crappy. I am wondering one of two things... could the coil pack'* power thinginmajiggy have gone out AGAIN, or are the wires just trashed?

I'm really not sure, but I have to say I think Bonnie94 might have the right idea. It'* cold as hell here, so I didn't get to take a long look at the vacuum tubes/wires. I did check all the ones I recently replaced, as well as others, and the wires, but not near the coil pack. I'll have another look after classes tomorrow morning and let you know what I find. It'* very worrisome, but I'm hoping this is all in my head and it turns out to be something simple.

Thanks for the help guys, and if anybody can think of anything else, please jump in!

I'm Frantic

If you could look in techinfo and find the way to scan the car for codes, see what you have.

You may have a sensor magnet, etc as well.

Your car didn't jump timing. No Bonneville on this Forum ever has.

while I like to expect the worse and hope for the best, those words are very comforting Bill, thanks. the car'* not throwin any codes at me, so we're gonna take the coil pack/etc to O'Reilly and have it tested and i'll let u know what happens...

That'* a waste of time. We've seen good ICM'* test bad, and bad ones test good. Their testing ability is VERY limited and unreliable.

Did you verify spark and fuel first?

Well, I got the car to start again, brought it over to my dad'* house where we're a bit more capable of working on it. O'Reilly didn't even know how to test the darned thing. Took it to AutoZone, and both the coil pack and control module tested bad. Obviously I'm gettin spark and fuel if it started again, so I'm wondering if the pack and module are really the problem. This would be the 2nd time it'* had to be replaced since I got the car...

Read what I said above.

There'* no way all 3 coils and the ICM are bad. Testing these is a JOKE. Test the coils per the Techinfo article yourself. Bench-testing the ICM at auto parts stores is a waste of time as I stated above.