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New MJ (pics) and Fuel Pump Question


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We are long-time owners of a 1991 XJ that we restored for our son. My son and I found a 1987 MJ this weekend.

 

97,000 original miles, 4WD, 4.0L, 5-speed short bed. Lot of cosmetic work, but engine is solid and body is straight. Picked it up for $500.

 

The engine is hard to crank. Turns and turns and turns before catching. The previous owner told us this problem started after he installed a new fuel pump at the gas tank. He said the gasket or o-ring did not seal correctly, and it is pulling air. He said that it is an easy fix - there is a bracket that spins around to release the fuel pump, and then the gasket is simply replaced.

 

Does anyone have experience with this? I searched on the forum, but could not find anything specific.

 

Thanks in advance for any info. My son and I are excited about restoring another Jeep!

 

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Thanks for the info. Located in NC.

 

We've had the MJ a week now, and we've had a little time to spend with it. What we have found is that it is almost impossible to crank - runs the battery down and we have to jump it before it will finally fire up.

 

Once it is running, you can restart it with no problem. I've had it sit as long as two hours and it still starts up fairly well. However, if it is left overnight, it is again almost impossible to crank.

 

In addition, most if not all of the fuel injectors are leaking a little.

 

Could the fuel injectors be the problem? Could they be allowing the fuel rail to lose fuel pressure, and everything has to prime after sitting for a long time?

 

I've checked the spark plugs, and they are clean and gapped correctly. I'm thinking if it were the CPS, it would continue to be difficult to crank after we get it started the first time.

 

As always, thanks for any ideas.

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Changing the fuel pump or the gasket can be a pain....just did it on my brothers MJ. you have to

drop the gas tank to do it. If you decide to change either one, I recommend disconnecting the drive shaft from the differential to give you additional room for tank removal.

I don't think the gasket/oring is your problem...it looks to me as if it is just there to prevent gas from leaking out of the tank...I don't see it as a pressure seal.

First thing I would recommend is to remove and thoroughly clean allthe ground wires in the engine bay, and then add an additional heavy ground from the battery to the front clip.

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Thanks for the info. Located in NC.

 

We've had the MJ a week now, and we've had a little time to spend with it. What we have found is that it is almost impossible to crank - runs the battery down and we have to jump it before it will finally fire up.

 

Once it is running, you can restart it with no problem. I've had it sit as long as two hours and it still starts up fairly well. However, if it is left overnight, it is again almost impossible to crank.

 

In addition, most if not all of the fuel injectors are leaking a little.

 

Could the fuel injectors be the problem? Could they be allowing the fuel rail to lose fuel pressure, and everything has to prime after sitting for a long time?

 

I've checked the spark plugs, and they are clean and gapped correctly. I'm thinking if it were the CPS, it would continue to be difficult to crank after we get it started the first time.

 

As always, thanks for any ideas.

i think its the injectors because that was the same thing mine was doing after it sat for 5 years try tapping the injectors with a screw driver while its running to try and free them up but don't do it to hard or u mite break them also unplug them then plug them back up that also freed mine up 2

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