Fuel Sender Interchange

[bigalpha]

Will a sender from a 1986 (2.5L only engines during that year?) fit into a 1989 MJ with a 4.0L RENIX?

 

Are the senders are different between the 2.5L and 4.0L tanks; what about the LWB vs. SWB? I know the pumps are different but not sure about the senders.

[jimoshel]

3 engines were available for '86. The 2.5 4cyl, the 2.8 V6 and the 2.1 diesel. The senders are the same. I have noticed a slight physical difference between pumps of different manufactures but not to the extent they didn't fit or work. The pressure between he 2.5 and 4.0 motors is 30 and 40 psi. However I have swapped them and never noticed any problem. LWB and SWB makes no diff to the sender.

[HOrnbrod]

There were three different fuel sending units used in the 86 gas models, all based on the thee tank sizes. So unless the 89 tank is the same size as the 86 donor, I doubt if the sender will fit w/o modification. I'm pretty sure the only differences were in the length and travel of the float arm.

[bigalpha]

So basically I'll need to make sure the tank in the 1986 matches the size of the tank in the 1989 for the sender to be plug and play.

 

If it's not, then the 1986 sender will need modification to work in the 1989 tank.

 

Did any of the three tanks offered in 1986 match the 1989 tank?

[HOrnbrod]

The tanks offered in the LWB 86s were 16, 18, and 23.5 gals. Same offerings in 89 depending of SWB or LWB.

[bigalpha]

Awesome, thanks! I'm trying to get my mom's MJ back on the road. Apparently the tank is so rusty it clogged the fuel pump and the sender is rusted badly too.

[jimoshel]

Must disagree. There were only 2 fuel tank offerings. 16 gal standard and 23.5 optional. I don't have a '86 MJ tank but I do have a '87,'88 and '89. I placed the '87 16 gal and '89 23.5 gal fuel pump and gauge assembly side by side. They are identical. However I can't guarantee the parts were OEM or if a PO swapped something.

The height and width of both tanks is identical. The extra 7 gal came from extending the rear end of the tank, thus making it only available on the LWB.

[HOrnbrod]

From the parts manual:

 

SENDING UNIT, Fuel ***

5200 3671 1 w/16 Gal. Tank - Carbureted Eng. - 7 Ft.

Box

5200 3644 1 w/18 Gal. Tank - Carbureted Eng. - 7 Ft.

Box

5200 3652 1 w/23.5 Gal. Tank - Carbureted Eng. - 7

Ft. Box

5200 3644 1 w/23.5 Gal. Tank - Diesel Eng. - 7 Ft.

Box

[bigalpha]

So it looks like the sender for the 18GAL carbed engine is the same as the diesel engine. If I find a diesel engine at the yard, I'll bring it home.

 

When I pull the sender, will there be a part number or ID number stamped on it?

[HOrnbrod]

My spare HO sender has the part number stamped on the mounting flange, so it might. But you never know from year to year. :brows:

[jimoshel]

I got my info from the '86 FSM and '86 owners manual. I'm looking at my parts manual, page 619 lower left hand corner. Shows 2 gas tanks.

sending unit, it only lists one, PN 83504483 for '86-'90

18 gal PN 83503398 and

23.5 PN 83502632 and the diesel tank, which we're not concerned with.

Also I do have a '86 MJ. Forgot about it. Can drop, measure the tank on it if needed for anything.

The '87, '88 and 89 tanks are out and laying on the floor if any info is needed on them.

[bigalpha]

W O W.

 

Thanks for hitting me up with this knowledge. Basically, I need a tank, fuel pump and sender to get my mom on the road again. There's an 86 in a yard not too far away from me. I was going to go pull the tank, pump and sender if it would interchange with my Mom's MJ.

[bigalpha]

Got to the yard today and the fuel tank was cut open. Apparently the salvage yard cuts all the fuel tanks open.