fire797

you should read the pinned stuff in the DIY section.... there is lots of info in there on all these questions....

My radio in my 89 mj did not work either. I found the pink wire check to make sure it was in good shape radio still not working. I ended up taking the fuse block apart and cleaned it with contact cleaner. I have a manual and the clutch master cylinder had leaked at one time. Now the radio works..... I also replaced all the fuses..... If you have a manual then I would bet money this is your problem.... no matter what harness is in the MJ

Okay so the pressure is 30 psi. I have had it running for about 3 hrs in the garage with a fan blowing on the rad and the hood closed. temp is around 210. I cleaned the ballast resistor connections did the cps upgrade. .7 vac at the connector. I also replace my starter wire it had several bare spots in it. I also cleaned the ground connection on the block. as of right now the problem is gone. It starts slow but it does start. thanks for everyones help and I apologize if my frustration upset anyone.... This forum has help me fix many problems on this truck since I pulled it out of the desert 8 months ago. Thank you for your time......

i towed the truck home. the next morning it started right up. when i used the bottle cap the fuel came out with great pressure. it squirt all the way a crossed the engine compartment. i don't travel with my fuel pressure gauge. so imho i think the fuel pressure is great.... this is a heat problem that is stopping the injector from working.....

rockfrog it will not fire at all it just turns over I have spark but no injectors GREAT FUEL PRESSURE...... fuel pressure is not the problem everyone...... I have the gauge and it is fine everyone.....I don't mean to be rude but we all need to move on fuel pressure is not the problem.....

fuel pressure is good. when the truck cools down it starts right up..... I have cleaned the block ground checked the sensor grounds and did the upgrade on the CPS. I have found some play in the dizzy shaft both side to side and up and down....

I have great fuel pressure...... what controls my injectors????? why do I have spark but no injectors????

correct dirty Comanche.... it starts if a pour gas in the throttle body........

all new fuel system tank to injectors..... 1989 Comanche and I have great pressure I used a bottle cap to get gas from the test port to put in the throttle body......

So I took the truck for a test run today. I live in las vegas. mild temps today water temp up and down around the 210 mark. just change to an open cooling system and that seems to be doing its job. However at a stop light the truck just died.... won't turn over..... truck sits for about 20 mins while my wife comes and gives me a jump ( new item to by jump box!!!!). truck starts runs for about a mile dies again. I can pour gas in the throttle body it starts then dies. this tell me I have spark and I check to make sure I have fuel pressure and I do. so this tells me the injectors are not firing.... Can someone tell me why??????

Thank you 91pioneer. great link!!!! problem solved. I cleaned the fuse block and replaced all the fuses and the radio works.....

I have a 89 MJ. I am a journeymen electrician. I have a good working knowledge of electrical system. I have downloaded the wiring diagram from the link I got on this website. It is for a 1988 MJ. It shows the radio being powered by the ETR fuse (constant 12v) and the wire label is red/tan. My fuse block has a label of ANT were the ETR fuse should be. The wire I have in the harness to the radio (constant 12v) is just red and it goes back to the dome light fuse. So is my harness for a 1989 MJ or has it been replaced with a different year and what year do you think it is?????????

I have excess play in my clutch pedal. I think it might be missing some parts. Is there a bushing that goes in the master cylinder arm? that is where the play is. And were can I buy this part?

Well the trans mount is different and so is the fuel pump. Has anybody found a new fuel pump lately???? I mean the whole assembly. Yes you can find fenders and bumper and stuff like that but try looking for parts to get the darn thing down the road!!!!

I have a 1989 MJ. I have been working on it for about a month now. I have replaced the fuel pump and rebuild the BA 10 5 speed ( I know.... Why? ) I have big plans for this truck but I need it running now. Many swaps are planned. However at this moment I keep running into the same problem. Finding the correct parts. The major parts supply houses seem to think that MJ and XJ are the same parts. Painfully I have found out this is not true. So here is the question. Were is the best place for MJ parts???

Has anyone tried using a stand alone EFI??? I have a 1989 Comanche and I have not hurt anything good about the Renix system. Looking to build a stroker motor and doing away with the Renix system.....

you never need a diagram if u just follow what paradisemj said. it works for every car made!!!!!!

I am putting a new pump in my 89 mj. I purchased one from autozone. I need the full assembly [ pump and sending unit}. It was a "direct replacement" not!!!! The strainer and sending unit face the wrong way. They do not go into the baffle in the bottom of the tank. Back to the store I go!!!!!

I did a transfer case swap and put the wrong switch in. One switch has a longer shaft then the other...... The switch stopped it from shifting.....

I am new to this group. You guys have such great information....

Great looking truck. I have a red mj also

This is an awesome looking truck congrats.....