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View Full Version : poor idle at initial start up


truckguy94
09-05-2008, 04:32 PM
Since I bought my '94 F150 4 x 4 (100,000 km) at the end of April, it does not want to idle at cold start up. The guy who does much of my mechanical work, did clean up the throttle body, a couple of months ago, saying it was brutally black. He figured this was the source of the problem, but he is a younger mechanic, and does not have the familiarity with a '94 vintage vehicle, so we left it at improved but not resolved at the time; but as we get into (cooler) September temps', the poor start- up idle is more noticeable.

Basically, at start-up, I have to lightly feed it gas, and start the truck moving by putting my left foot on the break, and giving it light gas with the right. After about a minute of driving, it is fine. On a really hot day, it will start fine without doing this, if I go out about 2 pm after having been out in the morning about 9- 10 am, but on a cooler day, I will have to use the "left foot on the brake" routine, for the first 30 seconds to a minute in the afternoon, too.

At no other time, do I have issues with fuel flow, or idle issues.

I asked the guy at the shop today when they pulled the engine codes, and the guy at the desk seemed more familiar with these trucks, even though they are an independent and not a Ford dealer. He mentioned the throttle body (a sensor?) but it could be other things related to the fuel pump losing fuel overnight at the engine (?).

Has anyone else had this same issue?

Bill

Northern Supercrew
09-05-2008, 04:47 PM
could be the IAC sensor. Idle Air Control. not sure if your year of truck has one. i think they're around the throttle body area. maybe Google IAC and see what comes up.

truckguy94
09-05-2008, 07:11 PM
the service manager at the independent shop said something about an IMC sensor...maybe I did not hear him clearly...I think it must be in the throttle body, somewhere, because cleaning it up DID improve it a few months ago

fordtough.ca
09-05-2008, 07:30 PM
That sounds correct IAC