I've been cleaning up a 3800sc in a GTP that had a lot or things that needed tuned up. All the vac lines were bad, lim gasket was leaking antifreeze, plugs shot, belts bad, new coolant elbows, n valve cover gaskets. Don't know if SC gasket was good or bad.

Everything was cleaned n painted, then reinstalled. Also did a MPS with 3.2 pulley. Everything should be pretty cut n dry but it's not. Still have a vac leak somewhere. Pretty sure it's the SC gasket again.

Blocked off the vac trees with plugs, blocked the map port with a plug n th evap on the tb. Vac leak Still there. I spray ether at thbase of the tb and engine smooths out. Redone tb gasket just to eliminate it. Still there. Redo SC gasket with coolant o rings. Still there same spot under the tb. I use copper spray n have sealed many 3800 without issue.

My ? Is have you seen warped lim's before or am I just grasping? This is e reason we first started servicing the car. All the vac lines were trashed. We did changed lim's cuz we had one already cleaned up. Think I created this problem from a bad lim? When the 1st vac leaks were just the lines?

Had this down for a week n it's my sons DD. His mother bought for a few years ago n we are not together so you can imagine what I get to here. Probaly y it's going bad . Out of all the cars to have problems with. Anyways could use advise asap. Chris

Check the EGR connection right under the TB...Had a leak there and took me forever to find it..

I had a spare egr here from a swap I did n swapped the tube out n still no difference. Funny thing is once the car gets warmed up it goes away. Not sure if the gasket swells up n seal or what. I guess next step is to clean up the original intake n try that. Wonder if it could be in the TB?

I would put a rubber cap on the PCV valve in the blower, then pressurize the intake with a pvc end cap, rubber coupler, and a valve stem shoved in a hole in the pvc cap.

Thanks for the suggestion. I've been at it this morning for a while n found a few things. Egr was leaking at the egr itself. Injector are leaking going into the head. Vac leak?

A boost leak checker is well worth the time to make it in these situations.

------------------
Turbo 3800 E85 5spd spec5
11.54@132.7

Ok some new info. Last night I put the car back outside, it has been in a heated garage the entire time. Went out this morning n started up the car. Ran beautiful, idle 1100 then down to 900 with no trouble with surging idle. Pulled it up in the shop, went to work for a few hours and come back, fired it up same old story. Runs good at high idle then kicks down, starts surging for a minute then straightens out nr uns perfect. Started it up let it idle down to where it would surge, then uplugged he maf n no difference for 30 sec? Or so then idle straightened out. Maf sensor? Does a vac leak go away within a minute of running every time like clock work?

Try removing the oil fill cap with the engine running and see if there is any change. You may have a vacuum leak into the crankcase, not to atmosphere. If there is a change, look closely at the pcv valve, make sure it is sealing correcly in it's bore.