Engine GMC Car Answers
I am back and need help.I need to re set the timing...2.5 what is TDC, I have all plugs out, #1 cyl. and #4 are at the top, the notch is pointing at the timing mark, and the rotor is pointing at #1 plug wire on the cap..won't start.If I pull the distributor (new)back out and start again from scratch what am I looking for at each cyl location, rotor and timing marks. Hope you can walk me through the retimeing of this motor.
Thanks Mark (grrrrrrrrrrrrr)MY TRUCK HAS A 4.3 LITER V6 WITH ABOUT 170, 000 MILES ON IT. IT DOSN'T BURN ANY OIL (JUST A SML PUFF WHEN STARTING AFTER IT SITS FOR A DAY). THE ENGINE ACCELERATES STRONG AND SMOOTHLY WHEN COLD BUT WHEN IT IS WARM THERE IS A VERY SLUGGISH SPOT IN THE MID R.P.M. ( BETWEEN 1500 AND 2200 RPM )FOR EXAMPLE, WHEN SHIFTING INTO 2ND ( AUTO TRANS ) IT FLS FLAT ON ITS FACE UNTIL THE RPM'S GET UP TO APPROX 2200 RPM AND THEN IT STARTS PULLING STRONG AGAIN. SAME FOR 1ST-3RD AND OD. LOW RPM POWER IS GOOD TILL ABOUT 1500 RPM. WHEN COLD THERE IS NO NOTICEABLE LOSS OF POWER AT L. THE MOTOR HAS NEW PLUGS, WIRES DIST.CAP/ROTOR, FUEL PUMP, FUEL FILTER, AIR FILTER. WHEN LOSING POWER, THE MOTOR DOSN'T MISS, IT JUST LOSES POWER.
ANY SUGGESTIONS GREATLY APPRECIATEDThe check engine light comes on and stays on for a few days. Then the light goes off for a week or so, then commes back on periodically. Ran a diagnostic check and it says that the fuel mixture is too rich. Which sensor needs to be changed. The car is running great. It's just that the check engine light keeps coming on.I am not quite sure how to catagorize this question. About two or three years ago I had my oil pump replaced on my 1993 GMC Jimmy S-15, and less than a year later had the lower intake manifold and a few other things replaced. Now my oil pressure is crap again. It reads at almost nothing, and when I stop it dips low enough that it trips the "check gagues" light. Thinking there is no possible way the oil pump is bad already I bought an oil pressure sensor switch today. I went to replace it and every mechanic, dealership, and parts store (including the back of the box of the part and my Haynes Manual) say that all Jimmys 1991 and newer have standard three blade sensors. For some reason mine has a single blade in there. No one can seem to figure this out, so I am giving this a shot. ANY info you have would be a help. Thanks.
Karl OttoMy dad is stuck in Arizona pulling a heavy load on a trailer. The problem started a few weeks back, before he was pulling the trailer, but it has gotten really bad in the past day.
The pattern has been that, while driving, the engine will quit. He lets it sit for 20-30 minutes, and it will start up again and run. The time between stalls has gotten shorter--as bad as 0.7 miles!
He has tried having the fuel filter changed. The mechanic checked the fuel pump at the time, and it had good pressure. Any other ideas?I am afraid I am going to wear out my starter prematurely! Engine used to crank right up, but is becoming harder and harder to start, at any temperature. After finally starting, it may miss sometimes for a few seconds with rich exhaust, then smooths out, runs fine after that. I would suspect fuel starving except for the rich exhaust. Plugs replaced, no help. I need somebody smarter than me to tell me what to try next.Engine runs great at idle and when up to speed but has terrible hesitation on acceleration (engine dies sometimes). Vacuum hoses have been replaced, timing is good, local mechanics have been stumped, I found a service notice: 86T186 -SEP 86 -Engine - Stumbles or Hesitates on Turns, but can't find details for this.