1995 GMC Jimmy Rough idle, runs rich

1995 GMC JIMMY

178,000 MILES • 6 CYL • 4WD • AUTOMATIC

123FISH

MEMBER
2 POSTS

Jimmy was running fine until I turned a corner, then it stated running like it was hitting on only 3 cyls, shaking a lot, running rough, putting out strong gas smell and small amount of white smoke. No water in oil. I was told by mechanic to replace fuel pump, sending unit, and filter. no change.
then to replace wires, no change. Then to disconnect catalytic conv, no change. Have replaced TPS, checked Map sensor, all to no avail. Still runs like older car with vacuum leak but I have checked the hoses too. Put a scanner on it but get no codes??? I am stumped, any suggestions what could be causing this?
Please help.

Jul 18, 2010 at 7:42 PM

EDWARD.S

✓ASE Certified Mechanic
166 POSTS

Hi. What It Sounds Like To Me Is The Injectors .The Fuel Pressure Reguator And Injectors Are All One Unit .Under The Upper Intake Manifold.The Black Plastic Manifold. Inside Is The Injector Assy.It Look Like A SpiderIt's A High Failure rate on the trucks.try to use a ac delco replacement much easier to install and you need the upper intake seals.

Hope This Helps You
Good Luck

Edward S.

Jul 18, 2010 at 8:08 PM

OBXAUTOMEDIC

✓ASE Certified Mechanic
3,711 POSTS

Hello,

I would suggest pulling plugs and see if any are gas fouled. If so possibly the CPI Assembly will need replacing, or as some of us call it a Spider Assembly.

Would aslo check fuel pressure. Pressure should be 55 - 61 psi. The fuel pressure test port is on the driver rear of engine. Check link below for test proceedure...

https://www.2carpros.com/car_repair_video/test_fuel_injection_pressure.htm

Post findings

.

Jul 18, 2010 at 8:09 PM

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