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sandkwagers 01-15-2012 08:46 AM

Starting Problems 4.7
Recently purchased 2000 grand cherokee lmtd. Wife din't pay attention to heat gauge and blew head gasket. Decided to just pull engine and replace with another. Got new one in, cranks over, but doesn't start. Noticed something I thought was odd. Prior to cranking over electric cooling fan comes on. Is this normal? Does anyone have suggestions on what may be happening. Looked simple enough, just plug and play. This isn't my first engine pulled. My first with so many electronics though. Thanks

cheapjeep 01-15-2012 10:23 AM

Re: Starting Problems 4.7
Were the engines the same year and did you use the ecm that was on your Jeep?

Scottina06 01-15-2012 02:21 PM

Re: Starting Problems 4.7
I would double check all connections...and yes...what year did the replacement come from? You may have to swap the tone rings

Frango100 01-15-2012 02:53 PM

Re: Starting Problems 4.7
Was there no problem with the cooling fan before the problem with the headgasket? If you didn't change the PCM, the problem is probably with the relay under the right headlight assy.
Did you check for any DTC set, regarding the no start issue?

sandkwagers 01-15-2012 02:55 PM

Re: Starting Problems 4.7
Engine came out of 2001, but I made sure it was 16t and not 32t and used existing ecm. Just checked for fuel, not getting nor am I getting spark, shot with starter fluid. Would the engine crank with a bad crankshaft sensor.

sandkwagers 01-15-2012 02:59 PM

Re: Starting Problems 4.7
I never noticed the fan coming on that early before. Where is this sensor located. And when you say Dtc set what do you mean? do you mean Top dead center. I assumed this engine would figure out timing on its own given the fact that it computerized. Thanks

Frango100 01-15-2012 02:59 PM

Re: Starting Problems 4.7
Yes, the engine will crank normally when the crank sensor is bad. But does the fuelpump run for the first 3 sec. after switching ignition on? Did you check the fuses?
With DTC i ment : diagnostic trouble code (key dance)

sandkwagers 01-15-2012 03:03 PM

Re: Starting Problems 4.7
I haven't rechecked connections yet, have checked for fuel and spark have neither. Would crankshaft sensor stop fuel and spark. Engine has same 16t to 16t swap no difference and not HO Thanks

sandkwagers 01-15-2012 03:10 PM

Re: Starting Problems 4.7
Tried the turning key on rapidly 3 times to get code but nothing, not getting any code. Have noticed the Key symbol in upper right hand corner come on, but goes off few seconds after taking key out. I am not getting any fuel to rail, and I don't hear any pump come on.

Frango100 01-15-2012 04:54 PM

Re: Starting Problems 4.7
You didn't get any code, but did it show "DONE" then in the odometer?
It looks if the PCM is dead. Did you check all fuses in PDC and junction block?
The key symbol is from the SENTRY key system. When the light is on, it normally means that there is a problem in the system or with the key.
An other member had this same light on and finally found a fuse from the auto shutdown relay blown. After new fuse all was ok.

sandkwagers 01-15-2012 06:54 PM

Re: Starting Problems 4.7
Nothing happened, odometer didn't say done or any code. I turned the key on and off three times and left on fourth time, no change. I've checked relay and fuse in engine compartment all looks good. Relay from another device that was working. It wouldn't be with the key, haven't done anything with that, would it. Haven't looked at auto shutdown relay, is that in the box in engine compartment or somewhere else? thanks for all the feedback Frango100

Frango100 01-15-2012 08:22 PM

Re: Starting Problems 4.7
Auto shutdown relay is indeed in the power distribution center under the hood. Which relay did you check sofar?
Check fuses 6, 16, 19 and 26 in the power distribution center. For some reason the PCM is not getting power. Also check all the connectors, to be sure that they are well inserted.

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