The TPS is good and so is vac. I haven't done a compression test yet though..

I compared the L67 harness that was still in the car with the L36 and they did match up at the firewall plug. (That was one of the first things I checked when I got the car )

It'* back there somewhere and the fuel trims are good.



So.... Compression test time?

Do me a favor and check the EGR one more time...specifically, where the tube bolts into the LIM.

My wife'* car was having very similar symptoms to yours, until I figured out that some d*mned idiot (me ) stripped the threads in the LIM where the EGR flange bolt screws in. Thus, the flange was not sealing well and giving me occasional fluctuating idle, lean trims, etc...but, like you, problems would show up only when warmed up and idling and decelerating...no problems when running / accelerating.
It was one of those maddening, intermittent things that passed all visual inspection, and would never happen when I was actively looking for the problem

(BTW, I fixed it by finding some good threads in the LIM with a longer bolt (spare LIM bolt Boosty sent me some time ago) and some washers as spacers between the bolt head and the EGR flange)

P.*., if you need a good compression test kit, you can borrow mine (but you'd have to pay some serious cross-country shipping )

Well..
I had the plate that unbolts the EGR to the LIM off and I inspected the tube as best as I could. I couldn't find any cracks or carbon deposits..
I also sprayed the crap out of that area specifically with maf cleaner (alcohol) and it didn't change the idle.

I can check it agian this weekend though.

Did your wife'* car have a good idle while in drive?
As soon as I put it in gear, it idles good.

Thanks for the compression tester offer. I'll let you know.
I'm not positive but I think one of my buddies has one.

Nah, it had a fluctuating idle when in Drive, also.

I did a compression test today..

Remember I do have a cam so compression will be lower..

Front bank:
1 = 115 - 125
3 = 120 - 130
5 = 120 - 130

Rear bank:
2 = 90 - 110
4 = 120 - 130
6 = 95 - 115

I put a few drops of atf in the low cylinders and it went up to 120 - 130.

When I had everything apart to repair the front head, I only replaced the front head gasket since I didn't have to take off the rear head.

So... even though the oil test is pointing to rings, should I replace the rear head gasket? Maybe the crash loosened it up?

I don't know if this may or may not help but I will tell you about an experience I had. I toasted a bearing on my 85 mustang'* stock motor. So I found someone down the road that had a 90 that was wrapped around a tree. We pulled the motor and swapped some parts on the long block then installed it. As I drove it for some testing the car kept overheating and we couldn't figure it out. Then we blew air into the cylinder and found it blowing into the radiator. We pulled the heads and found the impact moved both heads, poped the gaskets, and bent the bolts . Yeah so I am not saying this is the case but it might help to look at things from a different approach.

Blownville, I might have hit that hard.

This hard:


It was a wooden utility pole.. my car actually knocked it down.




What should stock compression be?

Any guesses as to what it should be with a mild cam?

Did my compression about a month ago (fully warmed up...still got the blisters on my forearms to prove it ).

Stock cam, stock heads (aside from SR rockers), and got 160 +/- 5 psi all around.

With a cam, I would expect compression to go down.

But are your heads decked? If so, how much? What kind of head gaskets? What cam is that you've got again (S1X?). Is your cam advanced (or retarded) from spec?