DrThunder Posted March 1, 2008 Share Posted March 1, 2008 Sooo...... sending unit and fuel pump replacement on a comanche. the job shouldn't have been that hard but, and there's always a but. The tank has plenty of room on side right next to the driveshaft, plenty of room to work and the sending unit is right on the side of the tank. For starters i cut the lines and gas starts pouring out, huh well the lines must have had some gas in em, nope i filled the tank a few days ago before i parked it. no big-e i take a nice gas bath and the unit is out. Next i go to put the new one in and match them up, different but close. everything is the same but backwards. i figure ok maybe there was a flaw in the original design and they figure to put the float and all near the front of the tank instead. it should work. look at the tank. put the unit in and its clangin against metal and $#!& so what the hell? I take the plastic shield off the bottom of the gas tank and see the tank is dented in the front. OHHHH, there's the problem! syphon the rest of the gas outta the tank and drop it to band the dent out. Finally get it out and inspect the damages when i see this $#!& in there. there is a pan in the tank doing god knows what and my new "different" unit is hitting this $#!&ty contraption. so now i sit at home at night wondering how the @#$% i'm gonna get to norwich with no other vehicles but the chevelle tomorrow in the 5 inches of snow. awesome huh? Link to comment Share on other sites More sharing options...
skimore11 Posted March 3, 2008 Share Posted March 3, 2008 Where did you get your fuel pump? I definitely don't want to buy mine there. I have been putting this one off for a while now. Link to comment Share on other sites More sharing options...
jaekl Posted March 3, 2008 Share Posted March 3, 2008 That looks like a baffling baffle. My quess it is to maintain fuel supply for the pump as the level goes down while you're sloshing the fuel. I don't see any holes to let the fuel flow, but your pictures look like the fuel is at the same level. Could you use the pump for your trip? The gauge or the inlet could bottom out before the tank is empty but might run out of gas unexpectantly. Link to comment Share on other sites More sharing options...
maddzz1 Posted March 4, 2008 Share Posted March 4, 2008 I remember reading that there are two different sending units. I forget if the other is for the 2.5 or what. I think they gave you the wrong one. You need to exchange it for the correct one. I think in the other thread the guy just needed the fuel pump so he switched it to the original sending unit. I will look for the other thread and post back if I can find it. Link to comment Share on other sites More sharing options...
maddzz1 Posted March 4, 2008 Share Posted March 4, 2008 Check out this link and read the 11th post down. http://www.comancheclub.com/forums/view ... nding+unit What brand is it? There is also something about needing to switch parts around on the bosch replacment in that thread Link to comment Share on other sites More sharing options...
DrThunder Posted March 4, 2008 Author Share Posted March 4, 2008 as for brand it was just one from autozone but i checked three other parts stores and got the same product. the pumps are the same but the sending units are differenent, thats where my problem was. my sending unit was rotted. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted March 4, 2008 Share Posted March 4, 2008 So Doc, did you resolve the problem yet? :popcorn: Link to comment Share on other sites More sharing options...
maddzz1 Posted March 4, 2008 Share Posted March 4, 2008 Is the sending unit bottoming out on the tank? or the filter or the float hitting on something? Link to comment Share on other sites More sharing options...
Duner Posted March 4, 2008 Share Posted March 4, 2008 You have fallen into the XJ - MJ trap. The parts manufacturers think that all of the parts interchange directly between the cherokee and comanche but as we know here from experience it is steering wheel forward, after that most of the parts are unique. The bowl or pan in the tank is to prevent fuel from starving the pickup tube on the fuel pump when conerning or climbing hills. Second the unit you bought is for a cherokee (it is the only unit that I can find anywhere for the 4.0litre engine) It will not properly fit the comanche tank. I completely dissected my new cherokee unit and reengineered everything to fit the old comanche pump assembly. If your sending unit works just buy the pump seperately, if your like me and need a new sending unit it requires some careful demolition and rewelding to adapt the unit to your needs. Float is on the wrong side, fuelpump pickup is pointed the wrong way, and after I relocated everything I had to lengthen all of the wires. I should have taken pictures of the project but I was just trying to get the truck up and running for school the next day. Link to comment Share on other sites More sharing options...
chicofuentes0224 Posted March 4, 2008 Share Posted March 4, 2008 After, hours and hours of research I never found a replacement sender assembly. So there's four choices I see. 1) do like duner did. 2) Buy the airtex pump part # AFE709IS which comes with the assembly. I've seen em on on EBAy from anywhere from $65.00 to $150.00 plus shipping. Then go to radiator connection and a cherokee 20 gallon gallon tank goes for like $100 with shipping. The only differnce I see is that the cherokee tank is about 3 inches shorter (height wise) and you might need to modify something to hang the tank. 3)Find a used one in good condition. 4)they usually go bad where the hard lines go into the "cap" to the sender, so somehow weld the cracks in the lines. Link to comment Share on other sites More sharing options...
djag12 Posted March 4, 2008 Share Posted March 4, 2008 One more option. Send it out to be rebuilt. Link to comment Share on other sites More sharing options...
djag12 Posted March 5, 2008 Share Posted March 5, 2008 Does anyone know the MOPAR/JEEP part number fot the sending unit? Is it 83506282? :roll: Link to comment Share on other sites More sharing options...
BLHTAZ Posted March 5, 2008 Share Posted March 5, 2008 Does anyone know the MOPAR/JEEP part number fot the sending unit? Is it 83506282? :roll:That is the number for the one for the 20 gallon 86-89 XJ tank. 86-89 MJ 18 or 23 gallon, 6 or 7 foot bed is a 83504485...BUT...as everyone here already knows, you can't find them anywhere :roll: :mad: Link to comment Share on other sites More sharing options...
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