5.0 AWD Starts when cold, not when hot...?

[SparkyJeff]

2000 5.0 AWD Mountaineer.

this issue popped up the other day, after driving around all day, I stopped at a store a mile from home, 20 minutes after stopping I get in and try to start her up. The engine barely starts, it's missing or not getting enough fuel, or something. I walked home, loaded a backpack with some tools, and rode my bike back to the truck. An hour after it wouldn't start right the truck started and ran perfectly. I drove it home- shut it off- tried restarting- same issue- barely running.

I replaced the ECT sensor today and drove around 12 miles, after stopping- same issue. truck barely starts.

When it is cold and i start it, it runs great, it idles smoothly in drive and park, plenty of power when i step on the gas.

But if it is warm i need to let is sit for an hour before i can start her up again.

Any thoughts?

Thanks
Jeff

 

[SparkyJeff]

I will add that this problem started right after helping another guy jump start his car...

I was walking to my truck and the guy parked next to me got in his car (with his lights on) and only got the solenoid clicking. He asked me to for a jump, so I started up and drove around so the batteries were close. I noticed my battery terminals were a little corroded. We hooked up, he got started, said thanks and gave me a dollar. I went about 150 yards to the parts store to buy some of those battery washer things (planning to go home and clean the battery terminals), Stopped for 20 minutes at another store on my way, and the truck would not run right after trying to restart.

The truck would start, kinda, it was missing, wouldn't run smoothly, the gas pedal didn't help.

When started cold, the truck runs on the highway, in stop and go, parked at idle while i do my business for 5 minutes. But if I shut it down, I won't get it running right again for 45 minutes. (It will do the barely start dance-- won't actually run right until it cools down)

What can cause this? the coolant was a little low, I remedied that and installed a new ECT sensor.

Should i be checking fuses? <--- Geez, I can do that anyway, which ones should i check? All? makes sense.

This truck has always been dependable. After jump starting some guys car, it won't start when it should be easiest to start. (while hot, after running for ½ an hour)

I searched and people have talked about ECT, IAC, coils and ignition module. What else am I overlooking?

help a guy out please,
Thanks
Jeff

 

[SparkyJeff]

Anyone?
Any ideas?

 

[SparkyJeff]

Today I cleaned the idle air control sensor.

Started fine when cold, drove for 15 miles then the truck started losing power, it gave up and quit six house away from mine.

I will find/buy a fuel pressure gauge, and see where I am with fuel pressure.

Shall I keep sharing here? seems like nobody home.

 

[MrQ]

Sometimes there are so many threads in this particular forum popping up at the same time that they get pushed to another page. Its from my experience that people rarely go through the second page to check for issues they can answer.

As for your problem, one of the issues that was diagnosed on my dad's v8 was that the insulator on the connector for the drive range module comes lose on the transmission and pushes the wire block out of the connector causing a no start when hot. Simple fix is to replace the connector, but that's up to you.

 

[Flag Gibby]

My first thought is a dirty fuel filter. The most mileage I have gotten out of one is 38k and I burned two spark plugs up letting it go that long. Ford is not joking when they say to change the fuel filter every 30k.

 

[SparkyJeff]

Yep, it's a fuel problem, I rode my bike to pick up a loaner pressure gauge,

I'm getting 10 to 20 PSI

I'll certainly replace the fuel filter, but, I'm probably looking at a fuel pump.
Ya think a filter might be the cure?

I may or may not have replaced the filter 20k miles ago (can't remember which truck that was)

The pump has 142k on it.

Do ya buy a pump at the dealership (10 miles away0, or go to autozone (6 blocks away).

Jeff

 

[MrQ]

Autozone has a good pump, just make sure that when you drop the tank you replace the sock and clean the tank. Don't do what I did and wind up replacing the tank twice, the fuel pump three times, and dropping the tank four times.

 

[SparkyJeff]

I was thinking of going the trapdoor route.
http://www.explorerforum.com/forums/showthread.php?t=182160&page=4

 

[FIND]

Check your fuel pressure regulator, EGR and TPS.

 

[Flag Gibby]

Yep, it's a fuel problem, I rode my bike to pick up a loaner pressure gauge,

I'm getting 10 to 20 PSI

I'll certainly replace the fuel filter, but, I'm probably looking at a fuel pump.
Ya think a filter might be the cure?

I may or may not have replaced the filter 20k miles ago (can't remember which truck that was)

The pump has 142k on it.

Do ya buy a pump at the dealership (10 miles away0, or go to autozone (6 blocks away).

Jeff

Check the pressure before the fuel filter and you will know for sure where the issue is. I had a vapor lock problem in the past (on a suzuki samari) that ended up being the fuel pump, but was very hard to pinpoint because the vehicle would only go into vapor lock after about 1.5 hours of driving. I am not sure what manufacturer autozone carries for the pumps, but I personally have had issues with the quality of parts that they carried in the past.

 

[AccordRanger]

Also check the fuel pump relay.

 

[Flag Gibby]

I was thinking of going the trapdoor route.
http://www.explorerforum.com/forums/showthread.php?t=182160&page=4

Don't do that! It is only a couple of nuts to drop the tank out of the straps and then you can get at the fuel pump.

 

[SparkyJeff]

Check the pressure before the fuel filter and you will know for sure where the issue is. I had a vapor lock problem in the past (on a suzuki samari) that ended up being the fuel pump, but was very hard to pinpoint because the vehicle would only go into vapor lock after about 1.5 hours of driving. I am not sure what manufacturer autozone carries for the pumps, but I personally have had issues with the quality of parts that they carried in the past.

The filter has over 20k miles on it, probably lots more. Can a filter bring the fuel pressure down to 10 psi? I'll change the filter first (would have changed it last night if i didn't need a dumb tool).

Can't/won't drop the tank, (Minnesota truck, limited garage space, roof is low, driver isn't a teenager)

 

[koda2000]

normally 20k on a filter wouldn't be enough to clog it and a clogged filter doesn't present itself with your symthoms. sounds more like the pump. with miles and after running for a while it may be getting weak. you can always do the easy/inexpensive stuff first. switch the relay with one of the other ones under the hood and change the filter. when it won't start, can you hear the pump running?

 

[pitbulldell]

sounds like the fuel pump to me, I had the same issue before and it was the fuel pump going bad.

 

[Flag Gibby]

The filter has over 20k miles on it, probably lots more. Can a filter bring the fuel pressure down to 10 psi? I'll change the filter first (would have changed it last night if i didn't need a dumb tool).

Can't/won't drop the tank, (Minnesota truck, limited garage space, roof is low, driver isn't a teenager)

I had a dirty fuel filter burn two spark plugs on my Mounty because the split fuel rail setup on the engines allow the right side to get plenty of fuel and the other side ends up getting starved (not noticable when cold, but once hot it is). I am in agreement with others that it is most likely the fuel pump only putting out a portion of the pressure it should, but I have seen many things that are a combination of components and that is why I reccomended checking the fuel pressure before the filter to isolate the problem.
As far as cutting a hole in the floor to access the fuel pump goes, I see that as introducing a vibration in the rear floorboard that will drive you nuts with the conditions that you drive in. Just putting the rear axle on stands/ramps is more than enough room to use a jack to lower the tank down and do the necessary work. The tank is really light if you siphon most of the gas out of it before you try to move/work on it.
I understand the delima, in the past I have had to make vehicle repairs in below freezing weather without a shop or a easy way to lift a vehicle. I am only offering advice and you are free to do whatever you want to your vehicle, but there is no easy way of going back once you cut an access panel.

 

[Flag Gibby]

I talked to some of the 5.0 mustang guys and they say that the engine runs fine with only 35 PSI fuel pressure and plugged lines/fuel filter can easily drop the line pressure down to 20 psi. Also, the 4.0 engine is a high pressure (63-75 psi) system but the 5.0 is a low pressure fuel delivery system (30-45psi). Thought this information might help you decide if changing the fuel pump is necessary.

Edit: See next post, the fuel system got changed on the 5.0 to a high pressure system in 1999.

 

[Flag Gibby]

It looks like in 1999 Ford changed things on the 5.0 fuel system and I think that you want to read this thread since it details fuel pressure check for the 5.0 and similar issues to what you have. http://www.explorerforum.com/forums/showthread.php?t=265157

 

[Turdle]

Pull the fuel pump relay and check the sockets it plugs into for heat damage. While the relay is out, swap it with another like it, there are several in the same power box

Let's ---see if the problem moves to the "new" circuit. Also, give the relay tabs a slight ( very slight) twist with a pair of pliers, this makes it contact the socket better.

Also, re seat the big PCM connector on the firewall. ( unplug it and plug it back in tightly)