zeihert

My 1995 ford 4.9 6cyl hesitates badly during warm up and continues even when warm but cant feel it as much.I replaced fuel filter,plugs,cap and rotor,plug wires dont look to bad.Ive got 92,000 miles on the truck.I cant seem to figure this one out please help.

mechhound

I would add a container of a name brand fuel injector cleaner to a full tank of gas. The fuel injector cleaner has done wonders for me. If that doesn't help, I would consider replacing the spark plug wires.

zeihert

I tried a good cleaner and it didnt help,plug wires arnt throwing any sparks.

wafrederick

Try puting on a new IAC motor or try cleaning the old one with Carb or brake cleaner.There are problems with them,that will cause it and is held on by two 8mm headed bolts.It could be the Mass Air Flow sensor too.

unclebubbles

If the above suggestions done help, heres a few things to check. As suggested above, cleaning the MAF sensor may do the trick. Does it run rough while it hesitates, or is it idling and running smoothly and just lacks power? If you mash it to the floor, does it help a little , or make it worse. If it helps, check the MAP sensor. Do you have two tanks? If so, switch to the other tank when its doing it and see if it makes a difference. If it does ok on the other tank, then the pump in that tank could be getting weak. A drop in pressure of as little as 5 pounds can cause this. If it does the same on both tanks, or you only have one tank, then check the vacumn line going to the fuel pressure regulator. Have the fuel pressure checked. Also check the engine coolant temp sensor, it helps control the cold start fuel enrichment and can also cause fuel feed problems at operating temp if its bad.

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rhandwor

Use an ohm meter if you don't get a reading you can cut off about 3 inchs and put new ends on. Sometimes I just use a tool I have to recrimp the ends.
If you are short on cash try this. The ohm meter should be around mid range.
I have used a small screw driver and removed them and reused them. You will have better luck if they are original equipment than some cheap wires.

zeihert

Can you tell me where the iac motor valve is located?

dstrick32

On the side of the throttle body!!

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92 Chevrolet Silverado 5.7 Automatic 2X4