mikekisss

i have a 1988 audi 80 4cyl. the car just dosent idle right. It revs up to 1600rpm and then drops down 1200 then picks back up going in cycles. I checked all the vacuum lines, replaced the intake boot, put on a new head valve gasket, new spark plugs, new oxygen sensor, cleaned the isv and throttle body. Yesterday, I accidentaly left the plug to the fuel pressure regulator unpluged and when i turned the car on it had a steady idle but when i plugged it back in, it would start reving like it did before. Any thoughts or suggestions would be very appreciated.

Harowing

check all the wires to fuel controls, might also check your fuel lines sounds like your shorting on gas a little bit intermitantly, oh, might also check the carbon canister valve, if that's bugging out it could be bouncing between rich and lean too, though I doubt that's the problem