Weird start/surging
Thread Starter
3rd Gear
Joined: Apr 2026
Posts: 3
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Weird start/surging
I have been chasing this weird start problem on my 94 c4, at first it was just slight rpm drop/ surging at red lights and then it completely stopped starting, traced to the optispark and got that replaced along with spark plugs. Was running/starting great after that but still had that slight rpm drop. Started getting worse a couple months later and having a hard time starting again. Found a vacuum leak and replaced all the cracked hoses. Thought it was fuel, changed the fuel filter and did pressure test everything was correct and still had the same issue. Ive replaced the battery as well as cleaning the throttle body and replacing the idle air control valve 3 days ago. It started right up after installing it didnt feel the surging at first but its still acting weird, idles better and starts better but it doesnt crank over first try every time and still has that surging, it gets worse with the ac on. Has never stalled out but its pretty bad i noticed the other day that my battery voltage drops with it ( stupid to just notice it not i know) but im at a loss, the only couple things i could thing of are alternator, tps or maf. Any help would be appreciated this things only got just under 90k miles (got it at 64k)
