When I push the clutch in while slowing down to stop, I've had problems with my 86 302EFI stalling out. I ran a bottle of injector cleaner through it because I just changed the oil. I havn't even gone though the whole tank of gas yet, it already seems better, but still stalls out once in a while. Should I be using better gas or something?

 

Check all vacuum lines for cracks or loose connections, could be a vacuum leak, when was the last time you replaced your pcv valve.
Check the catalytic converter, for any restrictions.
Replace the fuel filters.

 

How's the idle? Could it be set to low?

 

An EGR sticking open will also do that. The EGR opens while cruising and is supposed to close when you let off the gas to stop. If it sticks open, it acts like a vacuum leak and stalls it out. You can just clean the carbon build up off rather than replacing it and it will act like new.

I would bet a coke that it is the EGR. -g-

Good Luck,

Lee

 

I plugged the egr valve, and I had even tried removing and plugging the vacuum line to it, no good. It's a new egr valve and a new sensor on top too

 

The idle is set by the computer. But if you mess with the screw adjustment on the throttle cable, you can get it out of wack.

The first thing I would do is take the throttle body apart and clean it. Also take the IAC valve off the throttle body and clean it too. Make sure it moves freely.

Get it all back together, get it idling, and while idiling, unplug the IAC valve. If the engine suddenly comes to a stop, the throttle adjustment screw is too far back. If when you take the IAC plug off, the engine keeps running normal, then the throttle cable adjustment is too far open.

When you get it right, unplugging the IAC should make the engine slowly loose rpms and then die.

 

I took off the IAC yesterday and cleaned it out. It was free, but there was some soot in there, we'll see. I also pulled a couple plugs. They have about 10-15K on them, they were a little worn but looked pretty good. The wires, cap, and rotor are newer than that, probably 8-10k on those, but the rotor was carboned up on the end It was all premium napa stuff. I wire wheeled the rotor clean and put it back together. BTW I have an msd coil and spark box hooked to the TFI.

 

does your truck have dual tanks? If it does you are going to have two filter, one located in the the black box on the frame rail by the transfer case, and one located beside the transmission.

 

No, it's a shortbed. One tank. I've changed both fuel filters. The rear filter was BLACK!

 

Clean around the throttle butterflies.

Make sure the passage ways are clear going to the IAC

Then do the pull the plug test on the IAC.

 

Loosen the air dam for the throttle body, and spray some thottle body cleaner down the throat of the throttle body while your engine is running.

 

I had the same problem with my 1988 Ranger V6. I took it to the Ford place and they got it fixed. They said they had to desludge the throttle body.

 

Have you pulled codes.
That is where you should be starting.
I've found out recently, that a bad distibutor and hall-effect (pick-up) can cause similar problem. That is a bit harder to detect though until they fail completely.

Also, check your base timing.

It has been my experience that a vaccum leak will cause a fast idle more than stalling.

 

I'm not getting any codes. I did clean the IAC, it didn't seem too gummy though. The same day I had to clean a lot of carbon off my ignition rotor, and it hasn't given me a problem sense. (Knock wood) I'm thinking it was the rotor, although the IAC couldn't have hurt either.

 

It wouldn't hurt to replace the IAC if its carboned up real bad. If the truck was running to good, it could be the spark plugs are also carboned, and might need to be replaced. Pull a spark plug or two and check the condition of spark plugs, replace if necessary with some Motorcraft spark plugs. Some times it is necessary to remove the upper throttle body and clean thoroughly with throttle body cleaner, replace the upper throttle body gaskets.

Other items to replace are

1. PCV valve,
2. Cap and
3. rotor,
4. Gas filters,
5. Air filter
6. crankcase filter are sometime overlooked and need to be replaced,
7. And good set of spark plug wires,
8. Make sure the battery terminal are cleaned, it does make a difference on how an engine will run on these EEC IV computerized systems.

my 75 cents.