Crazy nightmare starting problem 02 4.0

[racprops]

Well here’s a problem we cannot figure out.



My 02, Ford Explorer 4.0 has an intermittent starting problem.



It has shown this early on, but only a few time when it had been run and fully warmed up and then allowed to cool of some like ½ to an hour and it will need cranking like an old flooded crab car. Cranking with at least ½ throttle.



She also started to get misses which turned out to be bad injectors # 4 and the #1 spark plugs would get an orange deposit on them, replacing them cleared it for a while.



So we replaced the injectors with a China made set off eBay. As far as I could tell nearly everyone was sell the same make and model.



Plus a new set of Autolite IridiumXP103 plugs.



NOW it is truly a hit or miss what she will do on starting…lights fast and funs fine OR the long crank. Cold, Hot or in-between, some time starts great other time cranking.



We check fuel pressure, 50PSI with first turn of the key. Looking for adaptor for the damn fuel rail port. Only tested a couple of times one day. Considering mount fuel pressure gauge under windshield wiper so I can check on many starts.



Note once lit she runs like great good power all the way to 6K red line.



One other winkle is normally she just leaps off the line (light) for the last couple of day it is not so fast off the line, there is a second delay and I put the pedal to the metal and she build up to a good take off. But she has lost the leap…



Replaced fuel pump relay. No change.



Test Cat by hammering on it looking for rattles, thought it might be intermittently clogging..no rattles.



If it was NOT such a pain to swap out the injectors I would do so as the habit of this intermittent starting showed up right after them and plugs changed so feel they might be the problem…..BUT other times she starts just fine and normal, cannot really blame them.



Any one fought this problem and won??

 

[mtstorey]

Well here’s a problem we cannot figure out.



My 02, Ford Explorer 4.0 has an intermittent starting problem.



It has shown this early on, but only a few time when it had been run and fully warmed up and then allowed to cool of some like ½ to an hour and it will need cranking like an old flooded crab car. Cranking with at least ½ throttle.



She also started to get misses which turned out to be bad injectors # 4 and the #1 spark plugs would get an orange deposit on them, replacing them cleared it for a while.



So we replaced the injectors with a China made set off eBay. As far as I could tell nearly everyone was sell the same make and model.



Plus a new set of Autolite IridiumXP103 plugs.



NOW it is truly a hit or miss what she will do on starting…lights fast and funs fine OR the long crank. Cold, Hot or in-between, some time starts great other time cranking.



We check fuel pressure, 50PSI with first turn of the key. Looking for adaptor for the damn fuel rail port. Only tested a couple of times one day. Considering mount fuel pressure gauge under windshield wiper so I can check on many starts.



Note once lit she runs like great good power all the way to 6K red line.



One other winkle is normally she just leaps off the line (light) for the last couple of day it is not so fast off the line, there is a second delay and I put the pedal to the metal and she build up to a good take off. But she has lost the leap…



Replaced fuel pump relay. No change.



Test Cat by hammering on it looking for rattles, thought it might be intermittently clogging..no rattles.



If it was NOT such a pain to swap out the injectors I would do so as the habit of this intermittent starting showed up right after them and plugs changed so feel they might be the problem…..BUT other times she starts just fine and normal, cannot really blame them.



Any one fought this problem and won??

I have a similar problem with my 2002 4.0 Explorer Sport. It has 150,000 miles on it. Non-starting happens only during hot weather. During winter there is no problem. It started happening last summer (twice). I turn it off, go into store and come out 10 min. later and it won't start. Wait a half hour or hour and it starts right up. Second time it happened, I called AAA. They couldn't start it so towed it to Ford dealer where I have had it serviced since new. By the time they got to checking, it started and they could find no problem. Third time it happened, it was a hot spell several weeks back ((90+ degrees). I had to wait about an hour before it started. Forth time was two days ago. Very hot (95+). It was following a Maryland Emissions Test. It would not start following the test. They had to push the car out to a parking spot. I waited 1-1/2 hrs before it would start. I have discussed the problem with Ford several times and they have no idea what the problem it. I replaced the fuel pump relay. re-seated all fuses and relays in fuse box. No help. I've thought of "vapor lock" but why would that wait for 150,000 miles before deciding to happen? It cranks fast but no start. When it finally decides to start, it barely turns over once before smooth running. Once running it has full power. Gas mileage averages 19 to 20+ mpg. It's like it has no spark in the plugs or no fuel to ignite in the cylinder. Hopefully someone has seen this before and found the cause. Thanks.

 

[stig111]

mtstorey, My 02 XLT 4.0 has similar problem. Consensus is it's the fuel pump.

2002 XLT 4.0 V6 4WD Very Occasionally Won't Start

 

[Mbrooks420]

I don’t think 50psi is that good on one of these. I’d also replace the gimmick plugs. The OHV and 5.0 are both picky with their plugs, the SOHC Might be too.

 

[domct203]

+1

Motorcraft SP500 plugs are perfect. Great power and life.

I believe fuel rail pressure needs to be in the 60’s, hopefully someone with direct experience will chime in

 

[mtstorey]

mtstorey, My 02 XLT 4.0 has similar problem. Consensus is it's the fuel pump.

2002 XLT 4.0 V6 4WD Very Occasionally Won't Start

I guess the fuel pump is about the last thing to try. I wish there was a way to ID the problem without just going ahead and replacing the pump.

 

[Mbrooks420]

I guess the fuel pump is about the last thing to try. I wish there was a way to ID the problem without just going ahead and replacing the pump.

There is, it should have more than 50 psi.

 

[mtstorey]

There is, it should have more than 50 psi.

The no start only happens when I am in a parking lot somewhere. Once I get it restarted after waiting about an hour, it runs fine and has full power. I can't reproduce the problem at home or at the Ford dealership. Do you still think is a fuel pump?

 

[Mbrooks420]

Spund

The no start only happens when I am in a parking lot somewhere. Once I get it restarted after waiting about an hour, it runs fine and has full power. I can't reproduce the problem at home or at the Ford dealership. Do you still think is a fuel pump?

Sounds like a coolant temperature sensor.

 

[mtstorey]

Spund

Sounds like a coolant temperature sensor.

I didn't know it had one. I'll check it out.
Thanks