NC Toy Boy

Ok Gents Thanks for All Your Help !!! I appreciate You sharing your knowledge and expertise with the Newbee !! I have the Original Fuel Pump back in and It started quickly, I have not road tested it yet, but I feel confident it will be ok. Also the Fuel Gage Reads Correctly now.... I'd suggest Staying Away from the US Motor Works USEP7072S - In-Tank Fuel Pump Module from Summit Racing.... who Now Says that they do not carry a fuel pump assembly for the MJ models.... The one they sent did not pump for very long.... Less than 100 miles since installed.... Now It sounds like the Motor is spinning but it has NO Flow.... IDK...maybe the impeller fell off.... I was Very Careful as to not running it dry when installing it. I did not compare it to the original one when I changed out the tank with the new one... I have compared them now and see some obvious differences.... I have attached a few pictures of the Original to Me working MJ Unit. The MJ unit has offset hard lines that make the strainer set down in the pan in the bottom of the tank. The Tank I used was the Spectra Model JP5B Fuel Tank... It Looks almost identical to the one I replaced. Don't forget to replace the 2 Vent Valves (I used Dormon 911-060) And the 2 Vapor Vent Valve Seals ( I used Crown ). I also replaced the Filler Neck Hoses with (Crown parts)and the inline Fuel Filter... Hopefully this info.will help someone... Thanks Again !!

I spent some time on this today before the rain started... I unhooked the fuel line before the fuel filter. When I turn the key on the pump runs for about 3 seconds and shuts off. With the Fuel Pump Relay. Jumper Pin_1 (Hot at all times) with Pin_4. The pump runs all the time but still no pressure or flow. I will pull the pump next.... I did get the original pump assembly out of the old tank and connected it to the harness.... Same results.... Pump runs for a few seconds when ignition is turned on and the stops... It does run continuous with the FPR Pins 1 and 4 jumped.... MY Question is.... what turns the pump off when it does not have pressure after 3 seconds???? I have not found anything about how to test the Fuel Pressure Regulator and in appears to only have Vacuum and return fuel lines connected... nothing electrical..

A few more Questions.... What Fuel Pressure should I have at the rail? Does the Fuel Pump Run continuously and the Regulator open/close to keep the pressure in range or does it cycle the pump off/on as needed? Is there a way to test the Fuel Pressure Regulator? Bypass it for testing? Does anyone have a Recommended Brand/Part Number for a Replacement Fuel Pressure Regulator? I have the Fuel Pump assembly recommended from Summit Racing Part# UMWUSEP7072S US Motor Works USEP7072S - US Motor Works In-Tank Fuel Pump Modules... I will be asking them for the specs on the Pump. Also, The Fuel Gage now seems to work backwards ??? When Tank is Full the Gage shows empty and Low Fuel Light burn is on ??? I do remember seeing some discussion on this in other posts....

I have picked up a new inline filter... I will change it next....

Ok Gents, I jumped pins 1 and 4 for the pump relay. The Pump runs and I can hear the pump running, I got some fuel flow at the rail, but not a hi pressure squirt when I pressed the Schrader valve. I tried to start it but it did not crank. I jumped the Ballast resister and tried again. No Crank.... I put a spark tester in between the coil and the coil wire. It has spark when I turn it over but still no crank. I put the Pump Relay back in and tried again.... still no crank.... What else could it be???

Help Please! Manche Lovers... This Thing is bout to Worry Me!! I have the 89 Pioneer 4.0, 5 Spd..4wd. Recently (March 2022) replaced the Tank and Fuel Pump Assembly... It worked/ ran well when first installed.. This weekend it started acting up. Spun over several times before it cranked a few times. Now it will not crank.... Runs with starter fluid. Now It sometimes sounds like the fuel pump pumps up and shuts off. Tank is fuel of fuel. But very little Pressure and flow at the Schrader Valve on the Fuel rail. What Pins on The Fuel Pump Relay (C216 I think) can I Jump out to ck the pump with the Ignition on. I have tried jumping the Fuel Pump Ballast. Is there a Fuel Pressure switch or just the Regulator and how does that work? Does the Crank Position Sensor control Power to the Fuel Pump? I am getting confused trying to follow the 88 Electrical Troubleshooting Manual posted on this site... Thanks In Advance !

Thanks For the Replies.... I have not had the MJ for long and just added fuel this weekend. Fuel gauge is not working. I noticed the leak just after putting 10 gals of Non Ethanol in at $4.55..... I got it back on the lift quickly and it appears to be leaking out of the seam on the Drivers Side next to the Chassis or may be above the seam where the fill neck joins the tank.

Help Please, I am getting Confused and Frustrated..... I am looking the replace the Leaking fuel tank in my Short Bed MJ... I have searched and it looks like I need the Spectra Premium JP5B 18 Gal Tank...... I cannot find a listing for a Replacement Fuel Pump with Sending Unit that lists to be for a 1989 Comanche, 4.0 EFI Motor with 18 Gal Tank..... Any Suggestions?

I don't see a center axle disconnect... I added more pics...

They Appear to be cast into the knuckle... I added more pics...

89 Comanche Pioneer? I think VIN 1J7FJ36L5KL510000 4.0 EFI Engine 5 Spd Trans Dana 30 Front Axle Chrysler 8.25 Rear Model 231J New Process Gear Transfer case BFG KM2 35 x 12.50 x 17LT Tires

I will take another look at the axle and get more Pics. Thanks!

Hi Jeepers, Newbie 89 Comanche (Pioneer ?) Owner.... I am trying to identify the Correct Front Dana 30 Wheel Bearing Hubs on my Comanche. The Axle may have been changed by the previous owner.. The cover has 30-7AF BC. I am Pretty sure that the hubs are still 5 x 4.5" Pattern..... I have not found any numbers on the current 3 hole Bearing/Hub Assemblies.

Anybody know where to buy a replacement Manual Door Latch, Handle and Arm rest for the passenger side of an 89 Comanche?