Cadillac Seville / Cadillac Eldorado Forum Discussion, Rough Idle. Can't figure it out... 1994 STS in Past Cadillac Vehicle Discussion; Ok here we go,Ii'll try to give all the info I can think of .
Car info : 1994 cadillac ...
Ok here we go,Ii'll try to give all the info I can think of .
Car info : 1994 cadillac sts 4.6 northstar 145,000 miles
4 new coil packs
Here's what the car is doing.
Rich feeling: Idles a little rough, you can smell gas / unused fuel at the exhaust tips. Gas milage is lower than expected (14.6 interstate). Litte sluggish off the line, runs good at crusing speed, but misses when in overdrive and the speed is around 50. (very powerful while moving).
No codes showing except 2 suspension codes (air bags are blown) and the memory lose code (disconnected battery)
It's been to local car mechanic, only thing he came up with is bad convertor (he was guessing I think). Dealer said bad vacuum leak at vacuum manifold ? I did find what he was talking about. It's the connector on the top of throtle body that has 3 vacuum hoses coming out of it. it's cracked and is sucking air.
Dealer said that part is not made anymore and they can't find it anywhere. I haven't looked I just got the car back yesterday afternoon.So I figured I would start here.
But I have always understood vacuum leak creates lean enviorment, not a rich one.IDK
Any help, would be great !!
P.S. I have owned another 94 sts caddy, same age, same car. so I know what this one is doing ins't right. The other one did have fuel problems too, but they were egr related.