Hi y`all

When i drive my car from cold, it will run nice and smoothe. But when it`s hot it`s like it misses a beat in idle and it vibrates, specially around 1100-1200 rpm.

Can it be a vacuum isue

The rotor and distributercap, as well as the ignitionwires and plugs are new. its a 305 with a q-jet carburator.

Kind Regards

Stig

 

Stig I just read an old post that was strikingly similar to yours!!

When the engine was cold it was running in 'open loop' and ran fine.

When the engine was hot it was running in 'closed loop'.

One problem he found was that one of his injectors did not have the proper resistance so he replaced all his injectors. It improved things. But he STILL had symptoms like yours.

He eventually decided to replace his (I think) EGR valve.

That combination of new parts solved his problems.

I will try to find that thread again and come back to edit my post with the link so that you can read it.

So it was a => combination <= of changes he needed in his case. He just kept cutting down through all the possibilities.

Here is the thread link:

https://www.thirdgen.org/forums/tpi/437186-running-rich-no-clue.html?highlight=pulse+iac

 

CamaroRider i will carefully read the thread you linked too, and then look into my car for some troubleshooting, and then report back.

Many Thanks for your answer and help.
Kind Regards Stig