Hello,
I have a 1992 bonneville, pulling a 44 (lean O2) and the weird VATS 58 code. 700 miles ago (now 140,000) I had to replace the head gaskets, the front one popped between cyl 1&3, replaced snout coupler with thanks to BC. Now, I have a rough idle, sometimes hesitation, boost gauge jumping ALL over the place, and weird misfires under the hood and sometimes stalling. Before you say ignition problems, I have changed plugs/wires and ohmed the coil packs. With the lean condition, it shouldn't be the ignition... but do any of you have a clue what I could start tearing apart to dig in to my baby?

Ignore the 58 Vats code. It'* a known bug in the 92 PCM. My first guess would be you're introducing outside air into the mix somewhere, making the O2 think it'* lean. Have you considered LIGHTLY re-tourquing your SC? The bouncy boost gauge is another clue.

willwren
thanks for the speedy reply... only when it is in major hesitation... I mean MAJOR hesitation... does the boost guage bounce. I will check the SC again, maybe some carb cleaner and looking for vacuum leaks too.... it is fun to be at 25 degrees and playing on the engine, thank goodness I can start it to have "garage heat" with a warm engine!!
i will keep ya updated... see if we can stir up anyone else'* opinion too!!

Jason

I would recommend cleaning the throttlebody as well. I had rough idle and major hesitation before i cleaned it. I think you're supposed to use intake rather than carbureter cleaner, but if you take all the sensors off first it oughtn't to matter.

When does it stall? Does it happen to stall during wide right turns or when you're under a third tank of gas? This would be the too-small fuel strainer on 92'*.

with a ame like John Deere Boy, I wouldn't expect that you had anything other than a green Bonneville... The hesitation isn't consistent, noticable at idle, but sometimes driving and coming to a stop brings the hesitation back... as for the gas strainer problem, I don't consider it a problem anymore, just a "driving style" but a major bummer when you are wanting to race and are going low fuel for less weight.... major bummer. I am gonna look toinight at the SC snout, retorque, and hope that works... the throttle body was throughly cleaned when I did the heads... and it was DIRTY... I will update!

oughtn't? Thats like shouldnt right?

lol yeah...shouldn't

try this post out http://www.bonnevilleclub.com/forum/...123&highlight=