Rough idle. Misfire Issue?


Inverse

10+ Year Member

Joined
Sep 12, 2009
Messages
2
Points
3,001
Vehicle Year
1990
Transmission
Automatic
Did a motor swap on my 1990 4.0L. Has a rough idle sounds like the engine misses. I cleaned the maf sensor, idle air, air temp. Did vaccum test, needle vibrates at 40 fluctuating a few psi.Please help.
 
If the 40 psi is the fuel pressure at idle you have a fpr problem. if the 40 psi is manifold pressure you have a serious turbo wastegate problem.
 
i believe that was the vaccum pressure measured at intake manifold
 
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