Mechanics

STUMBLING, MISSING, NOT REVING UP

1990 Plymouth Laser

Engine Performance problem
1990 Plymouth Laser 4 cyl Front Wheel Drive Manual

this vehicle will not rev up, it boggs and cuts out as soon as turbo spools up. It has fuel pressure (38psi), new pump and filter. All four plugs were fuel fouled. 150psi compression in all cylinders. Tried new plugs, wires, coil and ignition module. No air leaks found after maf to throttle body. Tried used crank angle sensor and known good maf. Nothing fixed the problem. Timing marks on cams and crank line up and timing is set at 5 degrees. Vehicle runs ok until turbo spools up. Exhaust is cut at downpipe to eliminate plugged cat. Any help or advice would be appreciated.
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Sapperton
August 12, 2009.




Problem could be coming from the turbocharger itself or the following

Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor
Bad TPS (throttle position) sensor
Bad or dirty MAF (mass airflow) sensor
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump)
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve)
Bad gasoline (fuel contaminated with water or too much alcohol)

Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include: Dirty or worn spark plugs
Bad plug wires
Weak ignition coil
Wet plug wires

Rasmataz
Aug 12, 2009.


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