Electrical Problems And Hard Start

[TheDude]

Hello everyone! I just purchased my first MJ yesterday and have been going over what needs fixed to make her anywhere near ready to drive. First up is the starting problems. She cranks for a good 15-20 secs before dramatically and loudly turning over running fairly well for a truck that hasn't been regularly driven in 7 years.. This may be caused by the fact that the exhaust manifold is leaking and the rest of the exhaust ends halfway through the muffler.

 

My second problem is that nothing on the inside of cab works.. No working cab lights, dash lights, radio, blower motor, or door buzzer. My only lead is that where some of the interior fuses plug in, the metal part the fuse contacts with is partially broken.. Is that likely the cause for nothing working inside? and is there any way to repair that or do I have to replace it?

 

Any ideas or comments would be greatly appreciated! 

[Comanchemodder]

Congrats!  First, you will need to provide some detail on the year/engine/transmission.  Not that I am an expert, but that's what the experts will ask.  Assuming it a RENIX systems, Cruiser's how-to is some great reading to understand the system and extremely valuable for diagnosing problems:

 

http://comancheclub.com/topic/41178-later-guys/

[TheDude]

It's the one I have listed in my signature since I only have one.. for now.

[kq.echo.413]

I just bought one with the same issue.. Do a engine ground check.. Hook a jumper lead to the front of the engine on the long head stud driver side ..then hook the other end to the hood latching point (that is a clean no paint latch in the front corner above head light) go fire your truck and see if that helps..I also unplugged my blower motor cleaned connection blower works fine now..and reground your dash ..that should get you in the right direction

[Oyaji]

Since it runs, you won't have a spark issue...

 

On a newly acquired vehicle, it's never a bad idea to start with a compression check to give you an idea of engine condition.

 

If you have acceptable compression, this sounds like a fuel problem. Make sure you're getting full fuel pressure, and that it comes up quickly. If it doesn't, refurbishing/augmenting the high-current grounds might help... after the starter, the fuel pump and injectors draw the most current of all other electrical components, and less is available for them under the high demand of the starter. Combined with the current demand from the starter, drop in available power might delay full rise to full pressure.

 

A vehicle that has high mileage and/or has sat idle for long periods may have marginal/partially clogged injectors. If you have full fuel pressure within a couple seconds after energizing the fuel pump, check the injectors for spray pattern and delivery volume. Injectors should not leak until energized, and once open should all have a uniform spray pattern, with fuel delivery within around 10% of each other. (Matched -flow injector sets are advertised as being as close in flow as within 1%.)