lude9285

yeah...is my already BIG problem bigger than i think. Why do i get misfires and random misfire codes for all four cylinders? Compression is only really low (100lbs.) in cly 1. Cylinder 3 isnt that high either (145lbs) but cly 2 and 4 are 175lbs.

Billman250

Last s2k I did a comp test on was about 220 on all for cyls.

Your cyl 3 compression is very poor, as well as cyl 1.

If the cyls leaned out, you'll get misfires across the board. 1&3 just happen to be the first to suffer sufficient damage.

As far as upgrading, You won't find anything to go the distance like stock. Even if you do, the gains are not worth it unless you build a full race motor.

Most importantly, you should find the root cause of the problem, so you don't fry the next engine as well.

lude9285

thanks billman for the post......but ive spent this whole summer trying to find the "root" of the problem. Checked/ changed parts to make sure i had spark...checked fuel pressure and injectors...so ive got suffient spark and fuel. Or at least thats what the 3 shops ive had it to this summer tell me! I finally found the reason for my misfires....low compression/leakage...but what could be causing this in the first place?

Billman250

Well, I said it along time ago, but the fuel trim info was vital at the time the problem started. The freeze data from the original codes would have showed if the engine was running lean.

Here's your best bet:

1. Pull the head. It's got to come off anyway. Have it vac tested, disassembled, be sure there are no damaged spots on the valves or seats.

2. Check the cyl walls. Damage is quite obvious on the FRM cyl material.

3. I would watch the fuel trim from the get-go when you're up and running again, to be sure you don't lean out (if that's what it was) the next engine.