Stalling out!

[jnc04]

Hey guys, got a question for you.....I have a 93 XLT, sometimes when I start it, the RPM's jump back and forth between 300 and 1300 and the truck stalls. Does not happen everytime. It started after I filled up at a gas station I have never went to before. Thought it was the gas, but a couple of mechanic friends said it could be a few different things. Like EGR, idle speed control, idle air speed, water in the gas...........It happened after fill up. I drove to one store, let it sit for about 20 mins, came out started and RPM's jumped, gave it gas and everything was fine. Went to get something to eat and started it up, same thing, this time it stalled, started back up with no problems. This morning after sitting over night here in NE PA, started just fine. Drove about 20 miles, went into my aunt's business for about 30 mins, came out started up and almost stalled, gave her gas and she was fine, tried dry gas to get water out, same thing still happened. It drives pretty good other than that. Maybe a little rough, but not anything too bad. Whats up? Any clues would really be appreciated.

 

[Bashman]

Since you have already addressed the water possiblilty I would consider either cleaning the Idle Air Control valve (do a search in this forum and you'll find directions) or a possible vacuum leak. The latter can be checked with an unlit propane torch. With the truck running turn on the propane and move it over the vacuum lines, rpms will increase where there is a leak.

 

[Vanquish502]

Change your spark plugs. My trucks do that too. Only use motorcraft though. I've tried almost every plug, they all suck.

 

[Positive Vibes]

What Bashman said.

Also could be a dirty MAF. Is your CEL (Check Engine Light) on?

 

[jnc04]

Nope, no check engine light, I'll try the plugs and wires. and look for a vacuum leak. Thanks guys. I appreciate the info.