Author Topic: 1973 CJ6  (Read 52865 times)

Wingman

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Re: 1973 CJ6
« Reply #885 on: August 11, 2018, 06:55:49 AM »
Almost all drivetrain control relays are mounted in the main fuse/relay box located in the factory GM engine compartment.

The pump motor must be getting hot to make that current draw grow to the point of relay failure. I had similar issue with my cooling fan at Big Dogs this year...
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rejeep

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Re: 1973 CJ6
« Reply #886 on: August 11, 2018, 08:12:18 AM »
These are remote mounted relays, not like the later fuse block mounted ones.
So basically external heat your saying is not a factor?

Pump is in tank... where and I going now?
I never wanted a red car.. always thought they were tacky and common...
I now have 4 very not common cars and they are all red.. :o

Wingman

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Re: 1973 CJ6
« Reply #887 on: August 11, 2018, 08:42:32 AM »
The fuel should be keeping the pump plenty cool. Hmmm...

Bigger relay?  ;D
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rejeep

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Re: 1973 CJ6
« Reply #888 on: August 12, 2019, 03:09:54 PM »
Haven’t really driven this much this year.. weather was crappy beginning of the spring and I have the Rover I have been putting shakedown miles on.

When I pulled it out of storage it was very hard starting/idle and there was a pop with a backfire...
I felt it was low on power, but I chalked that up to feel after driving a low geared dauntless in the Rover.

So I got it detailed and polished and when I started driving it home the temp gauge was running hot and wonky...   down a gallon of coolant with no leaks...

Make a very long story short... Intake manifold gasket gave up..  turned this around in smike time, had 1 night in the garage in between work trips..






I never wanted a red car.. always thought they were tacky and common...
I now have 4 very not common cars and they are all red.. :o

rejeep

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Re: 1973 CJ6
« Reply #889 on: August 12, 2019, 03:11:38 PM »
I was also able to find and eliminate the biggest gremlin and general PITA Ive had ever since this trust was built...

long explanation..

*UPDATE*

I like to post updates to persistent problems in hope it could spare somebody the same aggravation.

Since "new" I have had some underlying issues with the ignition/fuel injection system.
without going through all the details the 2 second version is I would experience random shut downs either while driving or at idle.  Sometimes it would fire right up after a min or not.

After swapping out the Duraspark module for a Mopar Orange box I no longer had any ignition trouble, but still random shut downs.
end of last year all signs pointed to the fuel pump relay possibly giving out, and I had not experienced another issue until yesterday.

Yesterday while running some errands the truck shut down at several traffic lights.. I would be idling just fine and then nada..  wait a min (a very long min in traffic) and it would fire right up.

I made it home after errands and picking up the kids.  It was shutting down on me more often than not.. it was finally failing with enough consistency that I felt good about diagnostic and finally nailing this..

I let the truck idle in the driveway until it shut down...  thinking it was the fuel pump relay I bridged the relay for constant 12 volts and let it idle..
engine shut down...  GREAT.. not the fuel pump relay

while sitting with the ignition switch in the 'RUN' position I observed some pulses on my Fuel pressure gauge, but nothing constant.
I don't know what tempted me at this point to wiggle the connections on the ballast resistor, but I did and i was able to replicate the pulses of the fuel pump.  Turned the ignition off for a min and turned key to "ON" and I got a solid pulse from the fuel pump and I was able to fire the truck.

I'll cut to the chase now..

In my dealings with the Duraspark (frying them constantly) I was told to throw a ballast in there to hopefully keep it alive longer..
The Howell computer has a "tach filter" in their harness that steps voltage down to 5 volts for the ECM trigger (taken from the - side of the coil)  Howell gets a full 12 volts from their supplied fuse block connected to an ignition on source.
What I think was happening is the ballast resistor would step the voltage down before going into the coil, coupled with the tach filter in the Howell harness the ECM wasn't getting enough signal to trigger the computer.

For right now I have the ballast resistor bypassed.  A full 12 volts going to a correct internally resisted coil (electronic ignition) and things seem to be happy.  I have a snappier throttle and so far no shut down from the Howell system.  I'm carrying a spare coil at the moment, but I feel like I finally have this licked.

Moral of the story for people that scrolled to the bottom looking for a picture..
too much resistance = too little a signal for fuel injection
I never wanted a red car.. always thought they were tacky and common...
I now have 4 very not common cars and they are all red.. :o

rejeep

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Re: 1973 CJ6
« Reply #890 on: August 12, 2019, 03:13:03 PM »
Now for the fun stuff... 8)

FINALLY taking the kids wheeling.. and finally getting myself out of the office..

This truck is Catskill Jeep Jambo bound...
Starting prep work this week.
I never wanted a red car.. always thought they were tacky and common...
I now have 4 very not common cars and they are all red.. :o

mr.mindless

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Re: 1973 CJ6
« Reply #891 on: August 12, 2019, 03:45:26 PM »
I really hope that's a final fix!! Long road
Quote from: etk300ex
oh lord!

M4wdFab

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Re: 1973 CJ6
« Reply #892 on: August 12, 2019, 04:34:26 PM »
welcome back
FLX picnic this weekend if you need a shake down attica trip!