crank and pressure question

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Jeeptech
Posts: 125
Joined: February 12th, 2007, 10:22 pm
Location: Elkhart, IN.

Post by Jeeptech »

For long crank time you want to check fuel pressure - the regulators go bad and leak back all their pressure back into the tank. If this is what's happening, the only sure fix is a new tank unit assy. (pump, reg, sender).
As for your oil pressure, I've seen some with worn cam bearings loose oil pressure hot at idle and a pump won't fix this. Need to check actual oil pressure with a master gauge and drive at highway speeds for 15-20 minutes straight. Check gauge at idle and see if it's dropping to less than 10 psi (2-3 psi is where the light comes on). This is repairable, but not cheap as the motor has to come out and apart to at least short block to replace cam bearings and several other common repairs should be done if you do this (like rear main seal and t-chain and possibly main/rod bearings). We see this at the shop in 80k plus units especially if purchased used and possibly not well maintained by 1st owner (read leased vehicles).
'98 XJ, long list, skinny wallet! Bummer.
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green50gt
Posts: 1356
Joined: January 16th, 2007, 10:08 pm
Location: Goshen

Post by green50gt »

1. I am here to testify that if it is indeed a pump issue that you have to replace the entire assembly. Tried just replacing the pump itself on my red cherokee and that was about $130 dollar mistake.

2. My green 97 TJ did that too. Replaced the oil pressure switch or the oil pressure sending unit and it got better, but didn't entirely fix the problem...of course didnt keep it around long enough to fix.
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