91 Bonneville timing sticks?

[allynnc]

My Bonneville runs great most of the time. Once in 200 miles after running constant speed and try to accelerate I either get a stumble before it accelerates normally. Three times it actually backfired before accelerating. Once in 200 miles it will act like the timing is stuck on full advance when starting. Engine will barely turn over, turning key off and trying again it will start right up and not do it again for a week. Both symptoms would say clean or replace the vacuum advance, if I knew where it was. Maybe with all these computers there is something else that will act like a sticky advance.???

[maxwedge]

What vacuum advance? , no distributor on the 3.8 engine. You need to have this checked out by a competent mecahnic, due respect here, but the tone of your question says you need professional help with this.

[allynnc]

Originally Posted by maxwedge

What vacuum advance? , no distributor on the 3.8 engine. You need to have this checked out by a competent mecahnic, due respect here, but the tone of your question says you need professional help with this.

I know it has no distributer. What else could cause it to act like it has a sticky advance? I have rebuilt engines without taking it out of the car on older cars. I am quite familiar with distributers. But it acts like a sticky advance with only occasional sticking. It happens two times. After driving a steady speed for awhile and then accelerating and sometimes when you try to start it acts like the (missing) distributer is 40 degrees fast...then it starts and runs fine. I drive 100 miles a day and this only happens once every two weeks or sometimes 2-3 times one day and not for a month.

[maxwedge]

Missing is missing?/ Like plugs or wires, spray the engine with some water or look at the wires in the dark see if any arcing, look for burnt or traces of arcing around the coils, there are a multitude of reasons, what you describe can happen.

[allynnc]

Originally Posted by maxwedge

Missing is missing?/ Like plugs or wires, spray the engine with some water or look at the wires in the dark see if any arcing, look for burnt or traces of arcing around the coils, there are a multitude of reasons, what you describe can happen.

Replaced the plugs and wires. I thought it worked...for a week or two, then it did it again. Something has to detect acceleration and change the timing. Thought it might be throttle position sensor, so I changed that too. Now I just don't know. I still figure it must be associated somehow with vacuum. By the way, compression is good, vacuum is good when tested, I've been tempted to drive around with a vacuum hose going to the passenger compartment to try to detect a leak.

[auto trainy]

Have you had to add antifreeze lately?