Mystery Part

[Davew]

I have 2 Comanche's that I use on my Coffee Farm in Hawaii.  Great trucks, will climb nearly anything. I just finished overhauling my 1989 MJ, reinstalled the engine and found that I have lost a part and wud like some help, I can describe it but I don't know name or part number.

 

Under Hood on LH side mounted on the inner wheel well is a white ceramic part about 3 inch wide with screw holding it to firewall and 2 wires with push connectors connected to it. I must locate another one but I do not know part name or number. I think it is a resistor but not sure. I swapped one from my other MJ and engine starts well but my other MJ does not start at all now. So it has something to do with power.

 

I have an 88 and a 89 MJ and the same part works on either truck so, would a similar part from a 99 Cherokee work? I am trying to find how big a pond I have to fish in to find a replacement part. I have already found that I cannot buy any new parts,  So I think I must find a an auto wrecking yard. Would help if I had Name and/or Part Number.

 

Davew

[Minuit]

99% sure you're referring to the fuel pump ballast resistor. It was added in 1988 as part of a "recall" to reduce fuel pump noise. It can be eliminated with no ill effects. A quick search is showing that 88-93 is the same part. Cherokees will have it also.

[sloride]

:agree:....  part number 33000682

[Pete M]

it can be eliminated, but those wires still need to be connected. :yes:

 

the computer puts a full 12 volts directly to the fuel pump at startup and then a couple seconds later switches power to route through the resistor which cuts the volts which lowers the speed of the pump which lowers the noise. 

[cruiser54]

Yep. Don't worry about bypassing it. 

 

Your MJ will just keep hummin along around your coffee farm........

[onlyinajeep726]

Connect the two Orange w/ black strip wires together and call it a day.

[jpnjim]

Learn something new every day.

 

I knew what it was, and why,

but I never noticed that early 4.0Ls didn't have them.

[cruiser54]

Learn something new every day.

 

I knew what it was, and why,

but I never noticed that early 4.0Ls didn't have them.

Only 87s came without them, and if a customer complained about fuel pump noise, there was a retrofit kit the dealer installed. 

[Strokermjcomanche]

 

 

Learn something new every day.

 

I knew what it was, and why,

but I never noticed that early 4.0Ls didn't have them.

Only 87s came without them, and if a customer complained about fuel pump noise, there was a retrofit kit the dealer installed.