1999 Ford Explorer engine won't run

BUCKHAMMOND

MEMBER
1999 FORD EXPLORER
6 CYL
4WD
AUTOMATIC
180,000 MILES

When turning my key to start my SUV, my engine turns over and trys to crank. It even runs as long as I have my foot on the accelerator. As soon as I take my foot off of the accelerator, the engine stalls out. I've replaced the spark plugs, spark plug wires, PCV valve, fuel filter, and air filter to correct this problem but it's not working. No engine light is on- so no codes present. I'm thinking O2 sensor, fuel pump, or ignition coil but don't know for sure. Shot in the dark. Any suggestions?

6 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Hi buckhammond, Welcome to 2carpros and TY for the donation

Do below to determine if its fuel or spark problem and get back with some results

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine atleast 3/16 away from ground-have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs, coil's resistances, distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it

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Thursday, June 17th, 2010 AT 2:02 AM

BUCKHAMMOND

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3 POSTS

I'm currently out of state and away from my broken down truck but as soon as I get back in town, I will try those things out. Most helpful.

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Saturday, June 26th, 2010 AT 2:52 AM

BUCKHAMMOND

MEMBER
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I tested the spark plug wires for spark and was getting spark at the wires. I hooked up a fuel gage to the fuel port and had zero fuel pressure when cranking over the engine. As a result, I just replaced the fuel pump/ sending unit/ fuel strainer. It's still doing the same thing. Which is engine turning over, but when gas pedal is pressed down the engine will run all day long. As soon as I let off the gas, the engine will die out. I don't understand how this is possible when I have a reading of zero fuel pressure! I haven't checked the fuel pressure since the new pump has been installed YET. I've heard the idle air control valve could be a problem, or the EGR. The EGR sounds like air was releasing out of it and the diaphram sounds like it rattles when the engine dies out. It seems contradicting to me that I have zero fuel pressure, yet my engine will run with my foot on the gas pedal. So far, i've replaced the PCV valve, spark plugs and wires, fuel filter, fuel pump/ sending unit, and air filter. Could it be the EGR or Idle control valve, or could the ignintion coil be weak or something. Or what about the O2 sensor? I've still got no codes though.

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Thursday, July 15th, 2010 AT 8:02 AM

RASMATAZ

MECHANIC
75,992 POSTS

Could it be the EGR or Idle control valve, Both will cause your problem-you shouldn't hear anything from the EGR valve start here-sounds like it leaking

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Thursday, July 15th, 2010 AT 12:58 PM

BUCKHAMMOND

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The truck is now operational. The problem turned out to be the idle control valve. I took it apart and cleaned out the carbon in the valve and then put it together again, and the truck started right up. So there's some FYI info for you in case you have another guy with the same symptoms. I can't explain why my fuel pressure was zero though, unless I ended up with two problems. The fuel pump and idle control valve. Oh well. I appreciate your help and love the web site, keep it up.