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Ignition Delay on 2003 Jeep GC
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pgw0963
New User
Jun 13, 2007, 12:21 PM
Post #1 of 4
(1245 views)
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Ignition Delay on 2003 Jeep GC
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Any help with this problem would be greatly appreciated as i am stumped as well as a jeep dealership and repair shop.
I own a 2003 Jeep Grand Cherokee Limited 4.7L V8 N-Vin
My problem started about 2 weeks ago and has these symptoms
-After the jeep has been sitting for a while (over 45 minutes) i get about a 5-10 second crank time before the car will start. I usually have to crank it, turn the key off, and crank it 1 or 2 more times before it will start. Once the car is running, there is no problem at all, it runs perfectly. No missfire, drag, or loss of power. And when i turn the car off and start it again, it starts just fine. The problem is when i start it after it sits. Like in the morning or after work.
I took it to the dealership and had it diagnosed with low fuel pressure. So they changed the whole fuel pump assembly.
I took it home and the repair had no effect on the problem
I also changed all the sparkplugs, fuel filter, air filter, and battery.
I was also getting a fault code P0340, which has to do with the cam sensor circut.
When i took the car back to the shop they ran diagnostic on all my sensors, tested them and re verified that i had correct fuel pressure. Everything checked out and they could not duplicate the problem.
They had no idea what could be wrong and said to "give it a couple days" .... right.
Has anyone expierenced this problem?????
I thought it could also be a fuel pressure regulator, but i understand that is part of the filter assembly.
HELP!!!!
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DanD
Veteran
/ Moderator
Jun 13, 2007, 1:36 PM
Post #2 of 4
(1243 views)
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Re: Ignition Delay on 2003 Jeep GC
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Has anyone performed a fuel pressure leak down test? The fuel pressure should not drop below 30psi after 5 minutes with the engine turned off.
Here’s how I would test this; connect a fuel pressure gauge to the test port on the fuel rail. Start engine and allow it to reach operating temperature. The fuel pressure with the engine running should be 44-54psi. Then turn the engine off and watch the fuel pressure gauge; it should not drop below 30psi after 5 minutes. That’s what the spec is but I would still be suspicious of an internal leak if after 30 minutes the pressure had dropped below 20psi. If the pressure drops you’re going to have to figure out whether the problem is the check valve in the fuel pump module, a fuel injector or the valving inside the fuel filter/pressure regulator that is leaking.
The whole idea behind holding pressure is that if; lets say the check valve is leaking; after the pressure has dissipated the fuel would siphon back to the tank. Leaving the lines, fuel rail empty; now when you go to restart the engine the fuel pump has to fill the lines, the fuel rail, pressurize the fuel and then the engine will start.
Maybe?
Dan.
Canadian "EH"
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thomas74
User
Sep 3, 2007, 5:31 PM
Post #3 of 4
(1223 views)
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Re: Ignition Delay on 2003 Jeep GC
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you my friend need a computer so of to the dealer you go
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thomas74
User
Sep 3, 2007, 5:33 PM
Post #4 of 4
(1222 views)
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Re: Ignition Delay on 2003 Jeep GC
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i had 3 jeeps do the same thing throwed out the same cold all 3 needed a computer
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