After one hour 93 explorer shuts off

[electronblue]

I am doing alot of research on this issue. After driving for about exactly one hour the car suddenly idles rough and shuts off. This happens while driving also. It will start back up sometimes but will not run correctly until the car cools down. Then it will repeat the above. I have started to do the different things suggested. I just thought that since it does this almost on cue, someone may have the answer. Thanks, great site

 

[electronblue]

I didnt get any replies, so I hooked up one vacuum line that was hanging loose. Not sure where it goes put it on the air box for now. Cleaned out the intake with carb cleaner. Patched some small holes in the air coupler. Drove to gas station got 89 octane for first time. Ran car for two hours without a problem. Although I now here a bubbling sound coming from the gas tank. I will continue working on testing and changing whatever I need. This is strange, Happy Easter

 

[MrShorty]

I know mine has intermittent "rough running" like that that is due to bad fuel pump that shuts down when it gets to hot. Easy enough to see with a fuel pressure gauge.

I can't think of anything specific to the one hour time. I'd probably start with basic diagnostics: fuel pressure test, pull codes (even if CEL isn't coming on).

 

[electronblue]

Thanks for the reply, the fuel pump was supposed to have been changed prior to purchase. But it will definitely be something to check out. Fuel gauge does act funny and I heard bubbling sound coming from fuel tank yesterday.

 

[nmos]

If you ever track this problem down please post a follow up. I've been fighting a similar problem for 2 years. In my case it isn't quite as consistent (unless you count always dieing at least once on each vacation consistent). It only happens in 85 degree + weather and generally after 2+ hours of driving although a long steep incline can trigger it sooner. At first I thought it was the fuel pump relay since cooling that area seemed to get it going sooner and at first a replacement relay did seem to fix it but the problem was back 6 months later. I did notice that that relay (and the ecc relay near it) seem to get pretty hot. My fuel pump is noisy but hasn't shown any other signs of trouble. I did replace the FPR at one point along the way so it's not that. Maybe a coincidence but my fuel gage hasn't worked in over 100,000 miles.

 

[Reejerey]

Sounds like it could be an overheating fuel pump.

 

[electronblue]

After it shut down on me again I had it towed to a local shop. They told me that it is the fuel pump. They actually told me that the pump was 500 dollars and it would cost 800 to put it in. I went back to where I bought it because he claimed that he changed it before I bought it. He checked the price of the fuel pump, as most of you know its 100 dollars. So I will pick it up and take it back to where I bought it. Thanks for the input-appears to indeed be the fuel pump.

 

[Verno]

Not sure if it still applies, but in the old days (before fuel injection and electronic ignitions) failing coils wold cause a stall at higher temps. Had something to do with the oil inside the coil breaking down...

 

[Tony H]

Fuel Pump Relays... they can heat up and cause this. it may look like a bad pump but try the MUCH CHEAPER Relay first.

The Coil Scenario wouldn't apply to the Ignition Pack on the 'X'

 

[Diff Whack Daddy]

Nope, definately the fuel pump. A relay would either be on or off. I had the same problem and the Ford dealership couldn't figure it out. They told me it was a bad MAF sensor and a clogged cat. I replaced those and the problem was still there. I took it to a different Ford dealer ship and they told me the same thing (It was still under warranty) I called BS on them and told them to check the fuel pressure, which was fine at idle, but apparently their diagnostic procedures don't include stepping on the gas pedal while monitoring fuel pressure. Long story short, it was the fuel pump, like I told the first dealership and they paid my warranty deductable and half of my parts cost for the cat and MAF sensor.

 

[Tony H]

Relays, Do heat up, there is an increase in resistance as they heat up, Then they can 'Break' connection and shut down teh Pumps.
Also the connection to the relay... if not solid can cause a resistance there causing the fuel pumps to run slower.

 

[410Fortune]

I second the relay or the pump

replace the relay, I had one that appeared good when tested... would fail intermittanly, it was corrosion on the terminals and the relay actually had the housing seperate from the internals so one of the pushpins was getting PUSHED up inside, it would pull out when you remove the relay, so it appeared to be good

Bubbling or gurgling from the fuel tank = pump is getting weaker

I suspect both, but would replace the relay first, its cheap and simple

 

[Diff Whack Daddy]

For cheap testing, just swap it with one of the other relays and see if your problem moves.

 

[locolarry]

whoilen my older ford did that it was the coil

 

[heavy_dman]

Been heaving similar problems with my 94, only have problem on warmer days, and the hotter it is the quicker it happens, The fuel pump was the 1st thing I replaced, and it was bad, hot wire burned in two between assembly and pump, only thing is problem persisted, changed fuel cut-off switch next, still persists, then the ECC and fuel pump relays, still happens, last thing I tried was ignition switch, went out again today, I also checked out the ECC and it looked fine, no bad capacitors or anything like that, but what I can tell you is that whenever it goes out, it completely kills all power to the fuel pump, and thats checking it at the wiring harness for the pump, if you have any more luck than I did let me know, cause when I pulled codes all I got was the O2 sensor.

 

[Tyexplorer]

Gurgling sound when warm

Has anyone figured this out if so. please post a solution? My 94 Ex with 127K has two problems. (not really there are more but I'll keeep it short). After hours or tests, I am pretty sure they are releated. Once the engine is warmed up and then shut off for 10-15 minutes, it idles rough for a minute. Not sure it's flooded or starving. At times I have smelled fuel but no leaks. It starts and idles perfectly when cold or if I wait and hour. An hours seems to allow the engine to cool enought for the temperature gage to drop below the "N" in Normal.

The other clue is when the key is turned, you can hear the fuel pump and gurgling/bubbling. This can only be heard during a warm state after sitting for 10-15 minutes and the level in the tank does not matter. There is no gurgling sound when when cold.

I have replace half the injectors, cleaned the others and installed a new FPR.

Is the engine getting too hot while sitting and boiling the fuel?

 

[MrShorty]

Is the engine getting too hot while sitting and boiling the fuel?

The fuel system should be pressurized, which would make it very unlikely that the fuel is boiling. As for the OP, my first suggestion is to put a fuel pressure gauge on it and see what the fuel system is doing on warm starts.

 

[Tyexplorer]

Fuel Pressure Results

Here are the results of Fuel Pressure measurements:

Key On Engine Off 38 PSI and will hold for >5 minutes

Engine Idle vacuum attached 26 PSI
2000 RPM vacuum attached 36 PSI

Engine Idle vacuum detached 38 PSI

Now the old beast is also breifly idling rough in the morning when stone cold. It still also idles rough when restarted warm and the bubbling sound in the tank always precedes that rough idle. In the warm start instances when no bubbling is heard in the tank, the beast will idle as smooth as new.
:exp:

 

[siguaw]

sounds like gas cap is not venting

 

[MrShorty]

Was the engine acting up during those fuel pressure measurements? The gurgling in the tank sure suggests something is up with fuel delivery. There are only two sounds I can think of that would come from the tank- the sound of the pump running and the sound of returned fuel streaming into the tank (this latter is usually not very loud if it can even be heard over sounds the pump makes).