Mechanics

ENGINE SURGES WHILE IDLING

Ford F-150

1997 Ford Ranger, 150,000 miles. When it's 50 or colder outside, once the truck is warm, the engine will surge or buck while idling, unless I give it a little gas. Check engine light is on (has been for over a year) with the same two code, lean fuel and transmission, yet no one can seem to find the problem. Have had the O2 sensor, fuel injector, all kinds of other sensors, etc, replaced, but nothing, other than the weather warming up, seems to help. In the summer, the truck runs just fine, although the check engine light stays on, even after the codes have been read and reset. Then today, an especially cold and windy day, started the truckand the check engine light was flashing. This is new. Any ideas on how to fix all of this. I don't mind braking with my left foot to give gas with the right, but I also don't want the truck to totally die on me. ANY help would be GREATLY appreciated!
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Julie Lohr
January 15, 2006.




Did you put in any gas line anti-freeze in to make sure their is no water in the gas for starters

Tiny
Dude
Jan 16, 2006.
Hmmm? Strange indeed. Usually surging is caused by the fuel injection system adding fuel or air unevenly for some reason. Possibly the engine temp sensor might be flakey, and in cold weather it runs in its flakey zone. Just a guess. I wonder if your car has a IAT sensor, (Intake Air Temp), some injection systems have these things. At idle the EGR valve should be closed and not working (unless being held open by carbon or something). It is possible that there is a vacuum leak near the injection unit that seals up when engine hot. Sometimes just running some water from a hose at a trickle on suspect areas will cause a change in operation so you can locate the leak. Possibly there is a defect in the IAC (Idle Air Control) valve and it is hunting or something like that. If you have a MAP sensor make sure the vacuum hose to it is tight and in good shape, if the hose is soft and gummy, replace it. Thats about all that comes to mind without more diagnostics.
Good luck
Datrryl.
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Tiny
DARRYL
Jan 16, 2006.

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