Hi Folks. We've had two problems within the last week with our 2002 Sport Trac (4.0l SOHC engine w/167,xxx miles). They may be unrelated, but I suspect there's good change they are. Both incidents happened while my 16 yo daughter was driving, so there's only very limited info on what happens. Both times, when I get there, it starts and runs fine. There is no CEL.

The first time it apparently stalled as she neared her destination after driving only about 2-3 miles at 35 mph or less after a cold start. She was slowing to pull into a parking lot and reported the dash lit up with warning lights, no power steering assist and no power brakes and no power from the engine. When I arrived it started and ran normally. She had fulled up the day before after two days of heavy rain, so I suspected water in the gas. I drove it more than 200 miles within the next 24 hours under a variety of conditions and filled up at a different station. I experienced no problem what-so-ever, and didn't bother adding any dry gas.

Then 5 days later (still on my fill-up) when she tried starting it after sitting all day, she reported the engine started but ran rough before stalling and never idled normally.

Doesn't the fact there's no CEL eliminate a lot of the upstream part of the control system......like sensors and actuators? This leaves things like the downstream parts of the fuel and ignition systems. I.e. from the fuel tank / pump to the injectors and the downstream parts of the ignition system.

What are the possible culprits? Fuel pump, fuel pressure regulator, injectors, ignition module, spark plugs, and....... what else? (I'm not that familiar with what these engines have) And of the possibilities, what are the most likely causes.

I'm still thinking water in the fuel......

Any thoughts would be greatly appreciated.

Thanks,
Bob

 

Just because the CEL is not on does not mean there are no stored or pending codes. It would be worth checking for pending codes. An intermittent MAF sensor could cause stalling and rough running, lack of power, etc. but only set a pending code in the early stages.

An intermittent or incorrectly adjusted CKP sensor can cause stalling as well, along with the fuel pump, etc.

Also, check the age of the battery. If the battery is getting old or weak, it might not have the capacity the engine electronics need to keep the truck running properly. And that could help explain why it acts up for her and not for you. She might be playing the radio louder, using windshield wipers, headlights, sitting at stop lights longer with the brake lights on the whole time, etc., draining the battery and keeping it from being able to support everything electrical that is trying to suck current from it. With modern cars, I don't get surprised if I need to replace the battery after only 3 years of use.

-Rod

 

Any luck Bob?I have an '01 explorer with a 4.0L SOHC. Initial problem was intermittent hesitation and stalling. Then no start on first crank followed by rough idle on second crank which cleared up on third crank. Finally my wife went to parts store where scanner revealed generic code for MAF sensor. Shortly thereafter, the vehicle stalled and left my wife stranded with groceries about a mile from the house. Checked MAF and readings were in spec with Hayes manual. Then went after ECT sensor ( ended up changing thermostat housing and sensors as there was a leak there already). At this point engine will start and run for a few minutes and then sputter out. Changed fuel filter because,once fuel pump pressurized, there was no pressure at rail. Filter helped this issue but engine still cut off. Bye the way fuel rail de-pressurized when engine stalled. Replaced MAF as that was original suspect. No change. I'm going to get a fuel pressure gauge and get accurate readings. I've been reading a lot and people talking about fuel pressure regulator, rail damper, vacuum control lines. Any ideas?
Mike

 

Hi Mike. Sorry I can't contribute much at this point.

Our Sport Trac has started and run normally (knock wood) ever since my post in early February.

 

Mike, have you checked your exhaust during that "second crank" period where the engine idles rough? Does the exhaust look/smell rich? If you increase the engine speed for several seconds does the engine smooth out?

Have you checked other "tune up" items such as the spark plugs and spark plug wires?

Getting good fuel pressure readings will be useful as well. Please post those once you get your gauge.

-Rod