2003 EB 4X2 Stalling at Intersections.

My daughter and her husband purchased a new Exp. in 2003. It's been a trouble free SUV. Low mileage, approx. 125K, always garaged and maintained properly.

Recently it cut out at speed on the freeway, but was easily able to restart. Sputtered on another occasion, but then recovered. Good power and acceleration, and easy to start in mornings.

This AM it wanted to stall out at intersections, and did once, with a little bit of trouble restarting. Other times it just dropped RPM to where it wanted to stall, but didn't.

It's back home and the diagnosing begins. What's the thoughts on where to begin looking for the issues?

Throttle body, fuel starvation, sensors, engine control module???

Fuel pressure check.
Possible IAC valve
EGR passages may need cleaning

Those are the first things that come to mind after reading the ecm for codes.

Stamp,

I'm being told that no codes were showing when the system was scanned. I would think that the OBD II would throw out some codes with these issues. Maybe trying another scanner would bring results.

Will start with examining the three potential causes you mentioned.

Thanks for the quick response. This truck gets a lot of local use on a daily basis and needs to get back into reliable service.

Since there are no codes stored that means the data being sent to the pcm while the engine is running, is rational and within tolerances. So the problem is outside of what the pcm is monitoring.

We are getting some results from testing for the issues that have caused a stall condition on the Exp. The EGR passages have been cleaned. The IAC valve was really dirty and was cleaned up. No work yet on the fuel pressure.

The truck starts easily, both cold and hot. When it gets to an intersection it idles OK, but if you try to accelerate too hard it chokes up and dies. Have a modest throttle response and it takes off smoothly. At normal highway speeds you can hit the throttle, the trans. kicks down a gear and off you go, no lagging, and no shutting down. When it does die at the intersection it starts up easily.

Would it be best to replace the IAC, rather than trust the cleaning up of the unit?

When I had a fuel delivery problem with my 2000 Exp., nothing I did improved or changed the problem until I replaced the fuel pump. It seems that with an immediate change in idle performance that we are on the right track working with the IAC valve and cleaning up the EGR passageway. Is this a reasonable assumption or should we still perform a fuel pressure test?

If we should do a fuel pressure test, what is the best procedure to get that accomplished? I'm working with a son-in-law that is mechanically inclined, but the Exp. has been so trouble free up to this point, he's not had an opportunity to get his hands dirty except on normal maintenance issues.

Thanks.....

Replaced the IAC valve two days ago, and the truck has been operated on numerous short trips since. Problem solved. Even though the valve was cleaned after being found quite dirty, the unit needed to be replaced. The idle is much smoother, and was reported to me that the truck appeared to have a lot more pep with the new valve. Every reportable symptom disappeared. This was the first hiccup the truck has had in 16 years, just amazing.

Thanks for steering the repairs in the right direction.

Can't believe nobody mentioned the bad solder joint on the fuel pump relay. 2003/04 are famous for it. You can have a new relay soldered in, after removing box, or get a replacement box ready to plug and play. Be sure you get right box though. Theirs at least 2 different ones on 03 alone. Hope that helps. Use your Vin# if you do the latter suggestion.

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