19vette89

the other day my 89 l-98 just started idling rough. swinging from about 1200 rpm to 600 rpm. it was idling so rough that the car was almost shaking or quivering. weird, because i've never had an idle issue. could it be the ethanol additive that is being put in to gas now? i know when i first got the car, i found straight pins inserted in to the tps connector??? i removed them months ago and did not see any change in the idle. any ideas? the car has been through a complete tune-up. also, it has a new fuel pump and filter.

jspeakman17

im going through the same thing! i was advised to check the injectors. it seems to be the consensus around here, so thats my next move. i replaced everything too, and im in the same boat! read some of the other threads for more details. it will help! good luck!

1989vette

Sounds like its a miss. Best thing to do would be to ohm every injector, and make sure every cylinder is getting spark. Make sure all 8 wires are good and producing spark.

seenalot

last November my 1989 started idling rough and hesitating. My injectors were replaced previousily when the car was throwing out codes, none this time so tried dry gas and injector cleaner. Nothing help so put it into storage for the winter. Started driving it late March, after a few fill ups the condition improved where its running like new.

Could be bad gas. Also never overlook the injectors but mine were throwing codes, neither of you are mentioning codes.

bd2626

A real quick thing to try is a shot of TB cleaner in the TB and see if the idle improves....TB may just be sticking, then maybe a vaccum leak?