ok when i stop at a light sometimes my car surges from 550rpm to 900rpm an then down to around 300rpm then smooths back out to 55o rpm for like 30 seconds... the time between surges is totally random.

but if i hit tap the gas at the precise time it surges, when it drops back down it just dies.

it also stalls allot in reverse


oh btw i have a stock 305 tbi v8

its always done this even after a full tune up......

 

i had a similar problem, but my camaro is carburated, 99% chance urs is fuel injected, and i have no idea how fuel injection works, but mine was a broken choke, i dont even know if urs has a choke lol.

 

have u had it scanned for trouble codes?

 

So full tune up...I presume plugs, wires, distributor cap & rotor, and checked the timing?
Is the air filter clean? You also might want to rebuild the TBI, it's not hard to do. If you've ever worked on a carb, you can do a TBI with one eye tied behind your back (or something like that)!

 

no codes come up....
tune up makes no difference....
my car does run verry rich...to the point if you are standing by the exhaust your eyes burn..

throttle body has new fuel pressure regulator and injectors already

new fuel pump and filter too

even a new o2 sensor thinking it would lean out the fuel mixture some

nothing has helped

if i had the extra $ id swap to carbeurated

 

Does it make a difference if it's a cold or hot engine?

 

remove and clean the idle air control valve. im not exactly sure where it is on the tbi unit itself, but it is a common issue that they get dirty. when they do, the stepper motor has a hard time finding the correct location, thus creating a hunting idle (aka surge). it could also be that the tps might be slightly out of range. there is a write up that will explain how to check it and adjust it. if you still have that problem, replace the iac assembly.

 

I am thinking IACV as well... or a tiny vacume leak... but codes...

 

With the engine surging with RPM's going up and down, I would start checking for a vaccum leak.

 

vacuum leak idk... ive been getting rid of lots of vacuum related crap.

the only vacuum stuff hooked up still is the brake booster. egr. climate control.
other than these 3 items i know of nothing else on my car still hooked up.

iac...is that the little sensor in my air cleaner?

and i dont notice the surging so much when it is cold but it is still there but hardly noticeable unless your watching the tach