99 Explorer - Fuel cuts out temporarily - No Codes

[dkam]

99 Explorer SOHC with 167k. Fuel cutting out, waiting 20 minutes then ok,
only to have it return.

I am having a strange fuel delivery problem which may or may not be associated with heat. I have searched but cannot find anything similar, at least with the terms I am using.

Drives fine, motor runs great, driving for a few hours in hot weather, I am stopped at a light and suddenly the idle begins to get rough. The fuel is cutting out and the motor starts surging. Up and down through the rpms, by about 500 rpm but still maintains idle without stalling. I step on the gas and it hesitates bad and about stalls. After a push to the side of the road and sitting awhile thinking it over, I bang on the fuel filter and it starts and runs fine. Drove it home and replaced the fuel filter and it's been fine in any weather.

I had no problems for a month....until.......we drive 340 miles on a road trip with no problems at night. Coming back about halfway up a decent grade, it starts again. This time I have the r's up trying to make it up the hill and it starts surging at 3k (no idle issues). Pull over, bang on the new fuel filter and still struggles. About 15 minutes latter of waiting and three short banging sessions (stop banging already). Starts and runs fine all down hill in 90 degree weather for another 130 miles. Just outside of town, it starts again. WTF? Pull over, loose hope, carry on the silly banging just in case, all for around 30 minutes, just about to give up for a tow and I'm on the road.

I pulled of immediately at the next exit, drive two blocks to an AutoZone. I have them pull the codes and ??? No Codes ??? Not even anything in history and it's had the same battery since I owned it. This is good and bad of course.

Can my fuel pump act this sporadic? Wouldn't it just stop working like other Fords I have owned? What else would cause this kind of behavior? Like maybe some sediment in the tank and another clogged filter? I just don't get the on and off behavior.

Regulator, filter, fuel pump, or the dreaded electrical?? I of course don't want to rebuild the fuel system part by part. Especially when I am thinking about what part to buy next on the side of the road.

Ideas? Thanks!

I posted this on the ford truck forum and had a suggestion to replace the filter. I still have not replaced the filter and am using the exp to commute.

 

[BrooklynBay]

Welcome to this forum! Start by checking the fuel pressure. If the pressure is normal, then check the computer, and fuel pump relays. Carry a spare fuel pump relay with you when you drive, and swap it in when you have this no start condition. Do you hear the fuel pump prime when it doesn't start? Do you smell gas when this doesn't start? A bad ECT (engine coolant sensor) might cause it to flood the engine after driving for a while causing it to run rough, and then stall. It then starts up again after it sits after the excess gasoline drains back into the tank. It's something like the old style carbureted engines which get flooded when you keep pumping the pedal a little too much, then try to start.

 

[chriswells78]

fuel pump can be that sporatic. How long has it been since you changed your fuel filter? It would be that sporatic if there was a problem such as a bad wire or a bad ground.

 

[IZwack]

As Brooklyn suggested, next time this happens, put a pen up to the schrader valve on the fuel rail and make sure fuel squirts out of it.

 

[dkam]

Damn that's fast service!

no start condition.

It'll actually idle and not stall if I keep off the gas. Just kind of sputter like there is just enough pressure to idle. When I was climbing the hill, I was running 3-4k and it had enough pressure to get me over to the side of the road. It wasn't like the fuel just stopped. The tach starts to jump, I'm going to say more like 1k versus .5k.

I'm liking the ECT idea because of the heat but could just 20 minutes of waiting get me another 2 hours of driving.

fuel filter? bad wire or a bad ground.

Fuel filter had around 1,000 miles since the last incident. Bad ground or wire would make sense if something changed, like off roading or wet conditions, but that's all been constant. The only thing I can think of is heat. Like vapor lock.

schrader valve

Still had enough to maintain idle and even after a few minutes I could rev the engine and it could red line but still spike and eventually stall.

The spike behavior was like a heart beat or a rev spike per second.

 

[dkam]

ECT.....

Looky here: http://www.explorerforum.com/forums/showthread.php?t=191493&highlight=engine+coolant+sensor

 

[BrooklynBay]

 

[dkam]

Thanks. I would have to have some way of confirming the temp to compare the voltage output. Not in my tool box. Plus, it may only malfunction at high temps.
*edit* just noticed I would measure the voltage for temp and ohms for the sensor.

Strangely, the gauge always showed normal temp. It never got hot, but when I opened the hood, it seemed really hot. This has also only happened in the heat on long drives.

I think I'll just replace it for $20. It seems like a quick fix since it's right at the front.

Never the less, thank you for leading me in the right direction.

I had also found some threads on EGR but I would think I would get all the related codes o2, MAF, etc along with stalling and rough idle. What do you think? Right now it's been driving like nothing happened aside from my new concern for related gas mileage loss.

 

[colindo94]

This would happen to me and it turned out to be a $5 fuel pump relay. just my 2 cents

 

[dkam]

I'll do that too. I am up to $25, I better slow down.

 

[manaen]

ECT.....

Looky here: http://www.explorerforum.com/forums/showthread.php?t=191493&highlight=engine+coolant+sensor

you may have a different fuel rail design than that thread. Some years do not have a FPR on the rail, it is actually attached to the pump in the tank. You can tell if you have a returnless rail setup, that is, a fuel rail that only has one line coming in and nothing returning. These types of systems in these years also have a higher running pressure so don't be alarmed if you test your pressure and come up to 60psi (like I was initially)

I'm not totally sure which years were like this(mine is an '01 SOHC it has it), but I wanted you to be aware of the possible differences when you are testing your fuel delivery. There was little information about these differences when I first started working on the engine.

BTW, if you do have that system, there is a surge supressor on the end of the one line(driver side rear) that could be confused as a FPR. It has a vacum line attached but it doesn't have the return line coming from it. It just caps the rear of the fuel rail.

good luck with your problem..

 

[dkam]

Thanks. From what I have read so far, it has an FPR.

Thinking about the behavior of the ECT, wouldn't that be a constant problem if it was bad? Plus, it would make sense to be rich from cold and stay that way, versus all of a sudden when it was hot and then act normal after 20 minutes. In my experience anything that gets hot on a motor takes an hour plus to cool. Plus, there was no rich smell to the exhaust. Would the ECT throw codes?

The motor was fluctuating in rpm versus bogging and stalling at idle. Would a rich system show this behavior?

I should also mention that I just had emissions done and the tester commented that it showed numbers like a new car. That plus no codes would rule out EGR, MAF, o2 sensors and other emissions equipment right?

I will certainly go with carrying a relay and waiting.

 

[dkam]

Fuel pump? http://www.explorerforum.com/forums/showthread.php?t=190268&highlight=fuel+pressure+regulator

 

[wickedrigs]

I am having the same exact problem. So far I have replaced the ICM. We will see if it fixes it. I will be changing the ECT sensor next. Here is what recommendations I have been given:

http://www.explorerforum.com/forums/showthread.php?t=285076