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Old 08-26-2014, 01:21 AM   #1
Rocking YJ

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long first crank, starts faster w/throttle

Jeep info: 1995 2.5, 5speed.
The first crank is long, about 10 seconds and then it starts. It starts kinda weak but the rpm kicks in right away. After that I turn it off, crank it again and it starts right away. If I let it sit for 5-10 min, it does the same thing, long crank until it starts. If I step on the throttle it starts quicker but still requires a pretty long crank.

Jeep already has new fuel pump, original failed about a few weeks ago.
It has a new cat, O2 sensors, plugs and wires. It also has a new crank positioning sensor. Plugs have spark, spark is white. There is pressure on the fuel rail.

Right now I'm really out of ideas, I checked for loose wires, disconnected vacuum lines and I can't find any. Any help or ideas would be greatly appreciated. Jeep starts and its drivable, but it drives me crazy to have a long first crank.

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Old 08-26-2014, 01:45 PM   #2
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What kind of pressure on the fuel rail? Sounds like the fuel system is losing its prime.

Try cycling the key a few times before trying to start it.

I had one that gave me similar trouble and it ended up being the short piece of hose that goes between the pickup tube and the pump on the fuel pump assembly. The clamps weren't tight enough to keep a good seal, and it would suck air if it was below 3/4 tank until the gas finally got there and swelled the hose to create a seal again. Installed fuel injection clamps on it since they are made different than regular hose clamps, cured the problem.

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Old 08-26-2014, 02:56 PM   #3
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That's very possible. I had a leak from the hard plastic line that goes on the fuel pressure regulator and replaced it with a regular rubber one with a clamp at each end. If I remember correctly, thats when it started giving me problems. I'll check that sometime this week amd update the thread. Thanks for refreshing my memory!
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Old 08-26-2014, 08:00 PM   #4
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I had a Cherokee that did the same thing, It turned out to be the smaller O-ring in the fuel pressure regulator (mine was on the fuel rail) Given that a new regulator is something between $50 and $100 dollars its worth getting a hand full of #7 O-rings at a hydraulics shop and replace them rather that buy a new regulator.
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Old 08-26-2014, 09:51 PM   #5
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Ok, I'm back from the parts store. With ignition on, the pressure was at 5 or 6. At idle, the pressure was at 31. What are the specs for pressure?
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Old 08-27-2014, 12:38 PM   #6
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I believe the pressure should be (don't quote me on this) but I'm thinking it is 39-42psi.
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Old 08-27-2014, 01:06 PM   #7
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31 at idle 39 with regulator unplugged
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Old 08-27-2014, 11:53 PM   #8
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Update: yesterday I went to purchased the fuel pressure regulator and slapped it on. Jeep starts on the first crank without the help of throttle. I let it sit for 30 minutes, an hour Nd overnight and it starts on the first crank without any problems now.*
Before if I let it sit for even five minutes it would crank for a long time and start, butvthe start would be weak until the computer stabilized the rpms. It would start faster if I gave it throttle but even at that it would hesitate. Now I'm just happy that it starts with no problems, it hasn't worked like this in a few months. Thanks everyone!!!

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