02 Explorer 4.0 stalls after starting/won't start at all.

[Ironhead Dave]

Newbie alert!

I have a 02 Explorer 4.0. It started to randomly stall after starting about a month ago. It will start, idle for about a second and stall. It will then crank but not fire. If I bump the starter, it will stumble a little and die for about 5-10 tries and then start fine. Lately it will not even try to fire. I have noticed that it smells of gas after it does this. Also, the fuel pump only seems to run for a very short time when it does this. Maybe a second or two. It will pump the pressure up from zero to about 10-15 psi and shut off. When it is working properly, it shoots right up to 62.

What I have done:

Checked fuel pressure. When it starts and runs, the fuel pressure at the fuel rail is 62-65 psi steady. Under hard acceleration, it will drop to the high 50s but otherwise is rock solid. When it doesn't start, it is at zero.

Switched out fuel pump relay. No difference.

Checked the MAP sensor and the air filter.

Unhooked the battery for a day to try and reset the ECM.


After searching the forums, I found a thread where a guy has a 99 that is/was acting exactly the same. They leaned heavily toward it being the anti-theft system, primarily the key. I have tried an alternate key with no success. I did not see where there was a resolution to the thread.

I don't think it is a fuel pump since when the pump runs, it holds pressure just fine. It doesn't act weak. I can go for days with no issues and then it will do it again. Doesn't seem to be temperature related. It happens first tin in the morning on the first start or after I have driven it for 45 mins. into work.

I'm at a loss. Please help!

 

[Ironhead Dave]

Is there any way to disconnect or bypass the PAT system? I really don't care if I have it and would like to see if it fixes my issue.

 

[Dsrtdweller]

I have an 02 Explorer Sport 4.0 also and it recently started doing the same thing exactly. I posted the problem and was told to maybe try a bottle of"HEET" in the gas tank to help dry out the moisture in the gas. Just put it in last night but it seemed to start better this morning and hasn't failed to stat yet. You can try any kind of gas treatment that help remove moisture and see if it helps? Dsrtdweller

 

[Exproblems]

Newbie alert!

I have a 02 Explorer 4.0. It started to randomly stall after starting about a month ago. It will start, idle for about a second and stall. It will then crank but not fire. If I bump the starter, it will stumble a little and die for about 5-10 tries and then start fine. Lately it will not even try to fire. I have noticed that it smells of gas after it does this. Also, the fuel pump only seems to run for a very short time when it does this. Maybe a second or two. It will pump the pressure up from zero to about 10-15 psi and shut off. When it is working properly, it shoots right up to 62.

!

A while back I had a similar issue with my Explorer one morning, it cranked over, but wouldn't start, followed by the heavy smell of gas fumes in the air. It would just turn over and not fire after that, only to drain down the battery. During the first key turn to start, I heard a very brief noise from the engine compartment while the engine was starting to turn over. Long story short, the rear timing chain jumped it's time (out of position) due to a bad or slack tensioner and the motor needed replacing. FYI, If the rear timing chain on the 4.0L goes bad, the motor needs to come out. I had no prior problems with the engine prior to that morning. Doing a compression test on each cylinder will tell you if you have a bad timing chain. If you get a "zero compression" reading on all 3 cylinders on either the right of left bank of the motor, that timing chain for that side is bad or out of time. Right bank timing chain is the rear chain and left is the front chain. Hopefully this isn't your problem, but the symptoms you have mentioned sound like the ones I had. Good luck!

 

[Ironhead Dave]

A while back I had a similar issue with my Explorer one morning, it cranked over, but wouldn't start, followed by the heavy smell of gas fumes in the air. It would just turn over and not fire after that, only to drain down the battery. During the first key turn to start, I heard a very brief noise from the engine compartment while the engine was starting to turn over. Long story short, the rear timing chain jumped it's time (out of position) due to a bad or slack tensioner and the motor needed replacing. FYI, If the rear timing chain on the 4.0L goes bad, the motor needs to come out. I had no prior problems with the engine prior to that morning. Doing a compression test on each cylinder will tell you if you have a bad timing chain. If you get a "zero compression" reading on all 3 cylinders on either the right of left bank of the motor, that timing chain for that side is bad or out of time. Right bank timing chain is the rear chain and left is the front chain. Hopefully this isn't your problem, but the symptoms you have mentioned sound like the ones I had. Good luck!

Ex-did your not start after that? Mine will start and run fine. Idles. No missing etc. It just will not start from time to time.

 

[Exproblems]

Ex-did your not start after that? Mine will start and run fine. Idles. No missing etc. It just will not start from time to time.

No, my Explorer wouldn't start after the timing chain jumped out of time. Just turned over till the battery went dead. If yours does start from time to time, then I wouldn't worry about the problems I had mentioned.
If your battery and alternator are good, maybe check the spark at your spark plugs, making sure the coil pack is good. Also check the wiring connections at the starter.

 

[jadez03]

Have you looked at the fuel pump emergency shutoff inertia switch? Maybe someone is accidentally triggering it intermittently. It's generally underneath the passenger dash on the right wall. I've also read threads about these inertia switches going bad and tripping without any intervention.

 

[Dsrtdweller]

Thx. Guys for the feed back all sound like a possibility ... I have a friend of a friend who is a Ford certified Mechanic who is going to check it out for me maybe this weekend. Will repost
what he finds then. Keep God in your Life for he knows all!

 

[ya13ya03]

Just went through this problem. Replaced fuel pump, filter, relay, fuse and a starter from the wife burning it up trying to start it. Add a $100 tow bill and I was over $600 plus a lot of head aches. Finally got it to stall and checked voltage at the pump and it was there but sketchy. Trace everything back to a melted conector on the inertia switch. I was all over trying to find answers. It had voltage but under a load it lost it. New switch and pig tail connector and it's good to go. Just though I'd share.