Mechanics

"94 . RUNS FINE, WHEN 1ST STARTED. BEGINS TO REQUIRE HIGH REVVS TO RUN, ESPECIALLY ON TAKE-OFF.

1994 Geo Tracker • 4 cylinder 4WD Manual • 300,000 miles

If turned off for a short time, gas pedal has to be floored. Runs very "doggily" until revvs built up & belches black smoke. If turned off longer time (hr+) starts normally & runs o.K. For a while. Tried replacing ECM. Ran fine for a couple of dsys, then back to problem. ECM has been tested by 2 re-builders who say it tests o.K.
"What's up w/ that?"
Thanx, Mack
Avatar
Mack
May 16, 2012.




I would have a back pressure test done on the cat converter. It may be clogged or a piece may be clogging the outlet.

Roy

ASEMaster6371
May 16, 2012.


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