'85 FB GSL-SE Sporadic Rev-ing Problem

[jimbo3san]

I am going to be as descriptive as I can on this problem...here goes.

I just purchased an '85 GSL-SE. I haven't registered it yet because I need to get all of the kinks worked out before I take it in for smog and saftey.

I have most of them worked out now but I have this problem:

When the engine is cold or warm and NOT UNDER LOAD, it will idle no problems. When I rev the engine up to 1500 RPM there is a stumble or a drop in what seems to be fuel injection after about 1 second. Almost as if the whole intake system stops working for approximatley 1/2 second then goes back to a smooth "normal" idle then about 1-1.5 seconds later the same thing happens. So the engine sounds like a waaaaahhh---waaaaaahhh---waaaaahhh.

This seems to be the problem all the way up through about 5000RPM then seems to go away. Keep in mind that this is all when the engine is not under load.

When I am driving it around it doesn't have this problem. Seems to be smooth and fine. It is only an issue when there is no load on the engine.

Which will be bad for smog becuase they test the engine while standing but run it at 2700 or so RPMs for 30 seconds.

What are the likely culprits here?

Thanks!


Jimbo3san

[fcdriver]

Ok this is probably not your problem but when was the last time it had a tune up?

You should not rev the engine while it is cold, it needs to warm before taking a load, this keeps the engine running happy and not hurting it.

You could check the tps to make sure there aren’t any flat spots on it to causing erratic readings.

You should also run the car (after it has warmed up) to heat the cats so they are at their optimal temperature so they work how they’re suppose to.