our 03 grand with the 4.7 died on my wife..while she was on the interstate. no warning and no previous problems. when i had it towed to garage....it flooded while they were checking it and filled the cylinders and gas came back out of the intake, filling the the intake box where the filter is....garage says they have never seen this before.....any ideas?.....thanx.....:brickwall:brickwall
07-04-2009 07:46 AM
any ideas please??
07-04-2009 07:57 AM
the fuel pressure regulator could have failed causing the fuel pressure to spike to extremely high pressure. i had it happen on a ford truck one day while we had a gauge hooked up to it press. went up to 100-110 psi and fuel flooded the cylinders. but only thing is that was a ford truck and you have jeep. what is the cranking fuel pressure?
07-04-2009 09:38 AM
thank you for the reply but i dont know the cranking fuel pressure and the mechanic didnt say....ill try to check but dont have a gauge
07-20-2009 09:46 PM
finally got pressure gauge on it......read 60 at initial crank and then drops to about 48.....needle on guage jumping whole time...regulator or pump?
07-20-2009 10:19 PM
A wj with the 4.7 does not have a regulator. Pump pressure should be 49.2 +/- 5 psi at idle. Can you get it fired and take a pressure reading? Sound likes you have one or more flooding fuel injectors. I have not seen a pump cause this before but I have not worked on many 4.7s.
07-21-2009 07:07 AM
The only way fuel can get into the intake manifold and cylinders is through the injectors. There is definitely something wrong with one or more fuel injectors and they are either stuck in the open position or cracked so that they leak. I'm surprised people at the garage couldn't figure this out.
BTW, the fuel pressure regulator is combined with the filter into a single unit performing two functions.
07-21-2009 07:34 AM
Isn't this the infamous "died on the highway" symptom that points to the CPS? I haven't had it happen to me yet but I thought this situation sounded pretty familiar to the CPS being bad.