duff0000

Another thing I am thinking that it might have ran too lean, My setup is a CTSC at the stock 5.5 psi, header, testpipe and exhaust. The car tends to run lean with the testpipe/exhaust combination, and has attributed to some blown motors in the past.

blackout

running lean usually generates more power until the point of blowing the motor or misfiring, does it knock at all??? if it was an all of a sudden kinda problem then i would say something else other than comp. or leak down testing. Nice to do but It shouldnt suddenly lose power unless you fried a ring running too lean....hmmm tough call

duff0000

UPDATE: Good news, prefromed a compression check, all cylinders were at 210.

Do you reccomend that I do a leakdown, being that all cylinders read 210?

I wonder what this problem could be. As stated before I:

-Removed and cleaned out IAC valve, and TB
-Prefomed MAP whack
-Switched out MAP sensor with a friends, ran the same
-Checked all vaccum connections for leaks
-Compression check: 210 across the board

whitemistress2k

Just throwing out ideas here b/c I had idle problems and a misfire CEL...
I had two clogged injectors on cylinder 2 and 4...
Had them replaced along with updated MAP sensor and cleaned the IAT sensor too...
Lots better now and no CEL or rough/dying idle...

duff0000

How did you know that the injectors were clogged?

Spec_Ops2087

No need for a leakdown test if compression test passed (or so I have read)

R3DS2K

check ur pvc and fuel pressure? also in the op you said a CEL came on.. did you pull code. if it turned off it could be pending or in history..

s2k_dreams

i had this happen to me once when i reset the ecu. im stock btw. but it seemed like the car had a difficult time relearning the idle control. i pulled over and checked to see if the fuse and MAP sensor were on correctly. I retightened (wiggled the MAP back into place) and also re inserted the ecu fuse to make it more tight and the problem was solved.

GL with figuring this out

whitemistress2k

My last option really... I'd already changed the plugs and the coils were swapped around...
I'm guessing that's why the CEL kept coming on as a misfire too...

CoralDoc

This is incorrect.

It is quite possibe for an engine to show decent compression and have poor leakdown numbers. The old engine in my Miata was an example of this; 175-185 psi compression in all 4 cylinders with 38%, 25% and 18% leakdown in 3 of the cylinders. The engine made poor power. Of interest, the cylinder with the second to highest compression had the worst leakdown number.

That said, it is encouraging that the compression numbers are good as that eliminates some of the catastrophic engine failure modes, like holes in the piston, etc. I'd still do the leakdown test to confirm other engine parameters are good. If nothing else, it gives additional data in diagnosing the problem and a good baseline for future checks.