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soteloel84 04-06-2013 11:57 PM

Starting Problem need help
Hi i have a 2002 overland 4.7 HO i over heated head blew up engine so I got new heads and had cylinder bored and new pistons, i reassembled engine installed, now jeep wont start it turns over trys to start after you release key. I replaced crank, cam sensor, new starter, new plugs, i checked to make sure got correct crank with 16 tooth gear, i have 49 psi fuel pressure, correct timing, i have spark, injectors are pulsing the main thing i have noticed is when you let key go it trying to start but then quits, i also noticed on my friends scanner it did not show pulse injector voltage. To me it seems like i got something knocking my ignition system out cause it will try to diesel when i release key from cranking.

Frango100 04-07-2013 06:54 AM

Re: Starting Problem need help
Did you replace the complete crank shaft, or was it the crank sensor? Are you completely sure that the valve timing is spot on, because when of a little bit, it already doesn´t start.

soteloel84 04-07-2013 09:22 PM

Re: Starting Problem need help
I had the crank and rod machined to new bearing, and replaced new crank sensor, timing is set exactly the way the manual said, i had 3 different friends that used to be techs look at it

Frango100 04-08-2013 10:39 PM

Re: Starting Problem need help
No fault code(s) set?
You said that you have spark and the injectors are pulsing, but then lateron you say that on a scanner there is no fuel injector pulse?
Was the tone-ring removed from the crankshaft and maybe not correctly installed? (not sure if this is possible, just an idea)
Did you check the auto shutdown relay if it de-energizes during the start attempt?

soteloel84 04-08-2013 11:00 PM

Re: Starting Problem need help
no codes at all

sorry, the computer showed no voltage but when i placed a test light it would flash,
i have no clue on the tone ring but i can find out

My question is when the ecm sends signal to injectors does it send it back to the ecm.

soteloel84 04-08-2013 11:47 PM

Re: Starting Problem need help
Hey fran i just read on a research that if my cam tone ring isnt the right one with the crank tone ring it will not start i got a complete engine rebuild kit with new cam gears chains and tensioners im gona look at that in morning

thanks for your input

Frango100 04-09-2013 11:09 AM

Re: Starting Problem need help
The PCM in fact doesn't send any signal to the injectors. The injectors have 12 V on one side and the PCM just makes a ground path for it to operate. There is no feedback signal from the injector to the PCM, but it can be that the PCM sees a current flow or not and can detect a faulty injector in this way.

soteloel84 04-15-2013 12:24 AM

Re: Starting Problem need help
That was the problem they sold me the wrong cam tone ring it would start for like 3to 4 seconds then die

Frango100 04-15-2013 06:31 AM

Re: Starting Problem need help
Good to hear you found the problem. Is it now running ok?

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