Hey everyone!

I have a question for you today regarding My 1985 Camaro Z28. While cruizing with the engine near 1000 rpm (+- 200 rpm roughly) the engine will begin to violently surge. this will continue until out of the above range, or engine load is increased.

During idle, the engine will not idle in this range. when idling up, it will approach 1000 rpm and immediatly jump to 1500. the opposite occures when idling down.

I am suspecting a distributor problem, but im not sure. anyone have a clue?

 

oops, forgot to mention. Engine is a G code 5.0 with an electronic feedback carburetor.

 

while driving its possible to be on the shift point where it will up and down shift back and forth although its difficult to do. you may want to check the ignition coil may be getting weak.

 

I will check the ignition coil. good suggestion. it does appear to be original. my fault again though, i forgot to mention it is a manual transmission. and i guess while im at it, a 7 pin ignition module electronic advance HEI distributor. distributor and internals are all oem spec. only addition is an MSD 6 unit, but this problem was present before the MSD was installed.

sorry everyone. been very distracted today. i think i hit all the important information though. lol

 

so, ive been doing some electrical work the last couple days and have had the battery disconnected. i re connected it this morning and took it out for a drive and.... my surge is GONE!! runs and accellerates smoothly all through the rpm range. WTF!?!

 

hopefully it doesnt return. One of the downsides of this type of fix is you were not able to identify which fix was the one that made the difference. Anyway enjoy it.... when a car is 25+ years old a new challenge is always around the corner.