mark 39

I went out this morning and turned the key and heard the pump prime and engine started. I unhooked ceramic ballast jumper bypass and restarted engine 3-4 times let it warm up and checked fuel pressure; 39-30 lbs. vacuum hooked-unhooked. Now I don't know if I should trust it or not; don't want to pay to get it home again. I won't be able to work on this for a few weeks due to eye surgery but would be nice to be able to get around if need be.

Drove my '87 MJ 4.0 AT on errands today. Several stop-starts no problems,then no start. Would sputter but not continue to run. Could not hear fuel pump when turning on switch. Jumped the resister on left inner fender,no go. Don't know what else to check before I call pump failure. Any suggestions would be welcome. If I need a new pump what brand(s) are reliable and what other parts will I need to order? Thanks for any help. Mark

Looks like someone tried to open the hood with a big pry bar.

Yes it's in the registry; I entered it in the last couple months. Painted by PO 8+ years ago and been parked outside the last 6-7 years since I bought. Must be the mild Wisconsin weather(lol) that preserves the finish.

Thanks Limey, I guess my mind isn't totally gone. The panic stop trick is something I will try. And Pete, I'm waiting on info from Jeg's on universal belts; US made, good price. Mark

Are original MJ belts inertia reel or pendulum lock type ? I thought I read somewhere that oem were side specific; after markets seem to be interchangeable side to side . Trying to determine if my oems are still usable or should be replaced . Quick yanks on belts don't lock either side. Would parking on a steep down slope allow gravity to simulate a sudden stop ? Any ideas other than hitting the proverbial immoveable object would be welcomed. Mark

I'd be interested in both sides. As for price not over $100 per.

1987 MJ Base 4.0/aw4/231/d30/d44/lwb W. WI Daily Driver Red ext./Blk int./Blk-Wht. factory cloth bench/column shift/full gauge panel/Durango? rear bumper

What is the indicator that designates an MJ as a "metric ton"? My '87 has the trans cooler, d44, 3+2 springs, bigger radiator (since replaced), but no Metric Ton logo on tailgate. PO said he had replaced the original box and that this truck had the "tow package".

Yes I've done most of Cruiser's tips. I'll have to find a replacement module and see if that cures the problem. Thanks everyone for the help.

Wipers work on high and low full time positions and mist. On intermittent only operates at slowest and fastest delay, nothing in middle. Bad delay module? Multi function switch ?Dirty connection? Thanks for any help in advance. Mark

Would one use the 2dr or 4dr Cherokee belts in an MJ ?

^^ ffdynamics.com Sorry I'm not confuser competent so couldn't give you a direct link. I should learn a bit more , I guess.

Thanks Don. I have another question you can probably answer . Do factory trans cooler lines fit or do I need to adapt with hose? I have the factory tow package cooler so do I even need to go through the radiator cooler? It does get below zero here in winter ; perhaps warming trans fluid wouldn't hurt? Any mounting problems or just plug and play? Thanks again . Mark

I need to put in a new rad and decided on FFD aluminum two row. I can't tell from the web site pictures or description if there is provision for stock fan switch sensor in left tank. Plan on using stock mechanical and aux. electric fan . Information on this or any other tips or warnings will be appreciated. Thanks in advance. Mark

Finally tried the REM that I got last December. How does all that info fit in such a small box? A few questions mainly for my edification. 1) ST Fuel trim default is 128. Should real time running number be higher or lower if everything is working properly ? 2) Is the voltage reading on REM for O2 sensor (12v-5v) from before the final connection to the sensor ? ( Back probe sensor side if in doubt ?) 3) Where did those of you with a REM route the cord through the firewall , dash, etc. Thanks for answers and any hints for using this toy to advantage. Mark

You're getting a lot of good advice. Having every thing VERY clean is quite important. Pay attention to duty cycle; tripping the temp breaker too much is not good for the welder. I did it to my first unit and I couldn't use higher settings. Breaker would trip almost instantly.

Good, you fixed it. What was the cure?

^^ {johnj's link} PO of my '87 MJ did much the same except did not weld on L-bracket. Dakota bumper only wraps about an inch around fender; not concours but looks decent.Perhaps adapt stock ends? Also tow rating is lower than Westin bumper if that matters to you.

^ +1

Is the vinyl you used the carpet runner style or is it a stiffer harder plastic?

Eastwood has a rust encapsulating spray with a flexible tube that fits on the nozzle. It's designed for use in blind spaces. I use Fluid Film spray in frame channels, rocker boxes, lower door panels, etc. myself. It's a lanolin oil base, doesn't dry out, has a not totally unpleasant odor for a week or two. Google "auto rust prevention", you"ll find more info than you'll want to read on fixing your problem.

Remember to lube the end of tubing with brake fluid and threads of flaring tool with light oil . Seems to help me make better flares.

Thanks again for all the help. Mark