Sorry about this guys- I'm going to post this in a couple of different forums until I can get this figured out, so please bare with me!

Here's the deal: I just bought a 2003 fX4 Screw with 47,000 miles on it. (Highway miles, I knew the guy who owned the truck before and he took good care of it.) Drove back up to school, about 300 miles, without a problem.
Yesterday I washed and waxed it - went all out. Topped off the tank and added a bottle of STP Super Concentrated Gas Treatment (to clean fuel injector and carburetor deposits). I drove about 20 miles today - around town and to school. Again- no problems.

Just now I went to dinner, (it's raining out if that makes a difference) and the truck just died when I was slowing down for a red light. I started it right back up and as I accelerated through the light the truck surges and then dies back about three times - kindof like I'm running out of gas.

What's going on? Could it be the gas treatment working through the injectors? The truck set over night, and I guess the stuff could have all settled to the bottom of the tank, and now it's working through the engine all at once , (I don't know anything about the stuff - does it mix in with the gas or is it denser/lighter?) Could the problem be water getting into the engine somehow? Oh- I forgot to mention- I put a K&N reusable air filter on when I bought the truck. Please help me out here guys - I've got a 3 month/3K warranty on this thing, and I'm only about 7 days/ 400 miles through it!

If I need to take it into my local dealer I will do it - but if you think it's something like a fuel filter I'd like to try that first.

P.S. after dinner it ran fine the two miles back to my apartment. Maybe I should just take it out on the highway and blow it out; but I don't want to get stranded out there!

Thanks a lot for any ideas.

 

I'd start out by replacing the fuel filter. The injector cleaner could have possibly dislodged enough crap in your gas tank to partially plug it off.

If that isn't the problem, you were porbably due to change it anyway.

Good luck.

 

Look for an air leak in the filter box or the inlet leading to the Throttle Body. A leak there will casue the iregular idle. Ask your friend if he ever changed the filter. If not it was due and as Jag mentioned the cleaner might have clogged it. If after you change the fuel filter nothing improves clean the IAC, Idle Air Control, valve.

Regards

Jean Marc Chartier

 

changing fuel filter tonight- that seems to be the easiest thing to try. It just seems strange that it ran 20 miles on the tank of gas, and then at 24 miles it starts acting up. I bought the gas from a "Kangaroo Gas Station" <--- cheapest gasoline around by 5 cents - might have something to do with it!

 

I second a sticking IAC valve.