Cranks but no start

[jloktalGst]

I am hoping that someone can give me a hand. My son has a 2002 4.0l Explorer, gas not flex fuel. He brings his family back to TX from Norfolk as he ships out to the Gulf, (not of Mexico). Anyway, the daughter in law was driving, truck quits, restarts once, long enough to get out of traffic, truck dies again, cranks, no start. I drive over, pull codes, nothing. I listen for the fuel pump, no sound....should be simple enough. Tow the car to my house, stop and get a new pump. Put the pump in, pumps fuel like it should, still no start. Get a check charging system fault on the dash. Battery takes a charge, pull the alternator, take it down, tests bad. I replace it, wondering how in the heck that could be the problem. Well it might have been a problem, but truck still doesn't start. Checked the fuel inertia switch, it isn't up. Checked the fuel rail, have fuel. Checked for spark, have that as well. The alarm light on the dash flashes slowly until I turn the key, it then goes off. (I believe that is normal). Through the scan tool, watch the TPS % as I move the throttle..it is getting a signal. Outside of just throwing more parts at this thing, any ideas? My next steps were the various sensors that control timing. I am really open to suggestions.....

 

[Exproblems]

I Outside of just throwing more parts at this thing, any ideas? My next steps were the various sensors that control timing. I am really open to suggestions.....

You can try doing a "compression test" on all the cylinders. If you get zero compression on all 3 cylinders on either the left or right bank cylinders, your timing chain is shot or jumped out of time. This will cause a crank (till the battery dies), no start condition. It happened to me last year. The 2002-2005 4.0L engines are prone to timing chain failures. It was the right bank chain or rear/guide tensioner that failed on mine and I had the motor replaced with a new, reman motor.

 

[jloktalGst]

You can try doing a "compression test" on all the cylinders. If you get zero compression on all 3 cylinders on either the left or right bank cylinders, your timing chain is shot or jumped out of time. This will cause a crank (till the battery dies), no start condition. It happened to me last year. The 2002-2005 4.0L engines are prone to timing chain failures. It was the right bank chain or rear/guide tensioner that failed on mine and I had the motor replaced with a new, reman motor.

Thanks! Not really the best news, but I'll give it a shot when I get back in town. As a note, the 4.0l V8 Jags have the same problem with timing chain tensioners failing from 98 to about 2002 when they replaced them with a metal part. I'll report back what I find, thanks again.

 

[Exproblems]

Thanks! Not really the best news, but I'll give it a shot when I get back in town. .

Your no start, but cranks over condition may still be due to something else. I was just giving you something to rule out. When my timing chain jumped out of time and the engine wouldn't start, there was a heavy smell of gas fumes in the air each time I tried to start it.

 

[dud3iknow]

my 02 xlt 4.0 had the same problem jumped time on me to.fortunate for me it did restart several times after but it ran with a miss to it. I to was stumped till a friend of mines tore it all apart.rebuild wasnt cheap so i went with a reman.good luck hope its something less costly.

 

[Boricua8412]

Same Issue New chains

You can try doing a "compression test" on all the cylinders. If you get zero compression on all 3 cylinders on either the left or right bank cylinders, your timing chain is shot or jumped out of time. This will cause a crank (till the battery dies), no start condition. It happened to me last year. The 2002-2005 4.0L engines are prone to timing chain failures. It was the right bank chain or rear/guide tensioner that failed on mine and I had the motor replaced with a new, reman motor.

I am having the same problem described here. Only difference is all my chaines and guides are new. Used the OTC kit and all went well. Could the right tensioner being bad cause chain to jump a tooth even with new guides. This has happened twice. (timed/put back together/timed again/ put back together again) Both times I had succesfully started the engine on the first turn of the key and it ran excellent! But after about a minute or two, heard what sounded like chain slap and then it stalled as described above. Both times the right side timing was off after stalling. I am thinking the chain tensioner could be allowing the chain to jump or perhaps something with the rear jackshaft sprocket. Any help?

I bought the truck with bent valves after the previous owner's failed attempt at timing it without the tool kit. So the new timing kit was already installed. He gave me very little information to what he had done to it. The tensioners may be the old ones...

Now i dont mind buying a tensioner or both if thats all that im going to need. I just dont want to buy it, take it apart a third time, re-time it, and all just to find out it could be something worse like a loose jack shaft sprocket or something.

I consider myself lucky that it hasnt bent a valve on me yet..

Thank you all for you time and help.

 

[Boricua8412]

Well i spoke too soon. About the valves not bending on me. Pulled the right head and there they were all three exhaust.valves bent The intake valve also hit but not as hard. Cant see if they bent or not. Will be replacing entire cylinder head as that is what apears to be my problem.. not the tensioner as i first suspected.