In preparation for intalling a racing beat exghaust system with headers i removed the air pump and split air valve and installed the blanking plate in its place. Drove it for one day and the idle was rough, engine continued rough up to 3k rpm. Todayi re-enstalled the split air valve and it idles normally agian.

Any ideas. Is the computer looking for censors?a vacuum leak maybe?

My car is 1985 gsl-se

Thanks in adavnce for your help

 

Probably a vacuum leak. Most people seem to have that problem after installing the block off plate. Spray some starting fluid or maybe something like wd-40 around the area and if the idle goes up, then you got your leak found.

 

Welcome to the forum!

Propane also works to find vacuum leaks.

 

yeah, you guys were right it was a vacuum leak. I sealed the blanking plate with some high temp silicone and the idle has gone back to normal. thanks again