Jeep Problems

[BusaDave9]

Some of you know I had engine trouble in Moab.

Moab 2019 Trail Report

We had 9 jeeps on the 2nd Annual Jeep-CJ.com Moab trail ride. A million thanks to Posi for planning this and to MrIPlayBass for leading the way on the trails. Ben pulled my Jeep to Moab with his pickup. I shot this picture on the way. Monday we went on SevenMile Rim trail north of town...

jeep-cj.com

Although Ben offered to help me fix my jeep I got it repaired at a shop owned by a friend. I've been too busy.

I got the cam, lifters, pushrods all replaced. We were worried about the cam bearings but they turned out to be in good shape.

The machinist really seemed to know my AMC V8. He recommended I replace the front plate for the oil pump because the original one is aluminium and flexes. Oil in the pump can bypass the gears instead of circulating around the engine.

I got my jeep back and i really wanted to take it into the mountains this weekend. My jeep isn't used anywhere except for the trails. I Wanted to get some miles on it before taking it on the highway. I want to break it in properly.

Yesterday I took it out on a dirt road 5 miles from my home. The engine died. It shut off as suddenly as if the ignition switch was turned off. I had fuel flowing through my filter (Clear fuel filters are great for troubleshooting).

My spark tester showed no spark.

I checked all connections.

I have a MSD 6A ignition module.



Installing it involved a lot of rewiring and I couldn't easily go back to OEM. The MSD module has a red LED that was on indicating it was receiving power.

Both leads of the coil go into the MSD. To troubleshoot I found out to remove the negative wire off the coil. I removed the spark plug wire that goes from the coil to the distributor. I used this with my spark plug tester. THen use a wire to ground that negative post to the chassis. If that produces a spark the problem would be the distributor (since it is now bypassed)

I did not see a spark. At this point I'm thinking I need a new MSD ignition module.

I did this troubleshooting yesterday. This morning I realized the test I did could also mean the coil is bad so I went out to measure the resistance of the coil. Just for the heck of it I tried to start it and my jeep started right up. Buy why? What was the problem? It was not vapor lock. Yesterday the engine had plenty of time to cool off so heat is not the issue. I also did not reseat any more connections.

I don't trust my jeep now. I'm not heading for the mountains this weekend. That's a disappointment.

The MSD 6A ignition module is over $200 but I think I want to have one on hand before I leave town with my jeep. What do you guys think?

The 9th Annual Jeep-CJ trail ride is in one month.

 

[Belizean]

Dave I'm not even going to think I know what happened to you on the road. I had something similar happen to me over 30 years ago. Jeep just died going down the road. Long story short it was a ground that was loose on the block, found after a lot of head scratching and looking. I have the MSD 6AL and love it and have never had a lick of trouble with it. Having a spare MSD would be nice. I would drive it around some and just stay near the house for some test runs until you regain some trust

 

[coldair]

I would check all your connections tighten all grounds. Does sound like a grounding problem.

 

[Lumpy Grits]

Double and triple ck that your GND connections are sound.
When it died-Did you think to touch the coil for heat?
You SURE it was not fuel related like vacuum or vapor lock?
Are you still using the OEM style horseshoe connector on the coil?
If so-change it ASAP to a screw terminal type coil.
Some engine bay pictures could be of help--
LG

 

[BusaDave9]

Three out of three say it's a ground issue. I hope that's it but I really didn't seem to do anything with the connections when it started to run.

When it died-Did you think to touch the coil for heat?

No I didn't check that.

You SURE it was not fuel related like vacuum or vapor lock?
LG

I used to have vapor lock problems. Since I installed an electric fuel pump by my tank vapor lock has never been a real issue. There are times when the engine gets hot and vapor develops in the fuel lines. The engine would sputter but keep running. The electric pump would keep pumping fuel and vapor. I would then drive on and on with it sputtering. I'd shift up to keep the RPMs low. Then it would start running good again. But that's not at all what happened this time. There was no sputtering at all. The engine shut off as suddenly as if I turned off the ignition while driving. Also this happened in the morning just 5 miles from my home so it was not hot.

Are you still using the OEM style horseshoe connector on the coil?
If so-change it ASAP to a screw terminal type coil.
LG

Nope, I have screw terminals.

Some engine bay pictures could be of help--
LG

Here ya go.

 

[BusaDave9]

The MSD ignition module is $235 to $250
I'd pay that if I thought I might be the problem but I don't want to throw money away.

 

[Lumpy Grits]

Have you called MSD for help?
You need a cleaner A/F.......
Try a jumper wire from the POS(+) side of the battery to the POS(+)of the coil and go for a drive.
This will remove the IGN switch, if there's any issue there.
LG

 

[BusaDave9]

Have you called MSD for help?
LG

Not yet. This happened Friday and by the time I did the basic troubleshooting it was too late to call MSD.

You need a cleaner A/F.......
LG

I clean it regularly but it's a reusable K&N. It's never white. I need to replace it anyway. It's in bad shape.

Try a jumper wire from the POS(+) side of the battery to the POS(+)of the coil and go for a drive.
This will remove the IGN switch, if there's any issue there.
LG

Even the positive wire on the coil is not always +12 V. Both wires to the coil go into the MSD now. It doesn't matter anyway. It's running. I want to keep running it and when (or if) it dies I'll do some testing. With MSD they recommend shorting the negative to ground instead of bringing the positive to +12. This should produce a spark. The LED on the MSD along with my multimeter told me that the MSD ignition was getting 12 volts.

 

[Lumpy Grits]

If it dies again-And it will cause that just the way intermittent ele issues work.
I would look at the ign switch area.
When you installed the MSD. Did you remove the resistance wire from the wiring loom on the fire wall? You should...
How is the MSD attached for battery power?
LG

 

[BusaDave9]

How is the MSD attached for battery power?
LG

Here's the drawing I made for my TeamRush Upgrade thread.
https://www.jeep-cj.com/forums/f2/teamrush-ignition-upgrade-11416/

If it dies again-And it will cause that just the way intermittent ele issues work.
I would look at the ign switch area.LG

I know the MSD is getting 12 volts because I measured it and the red LED is on.

 

[Lumpy Grits]

I had to ask, 'cause I've seen folks just run the NEG(-)to the fender and such.
Double check the power leads are 'tite'.
HINT-If you have RFI issues with your radio. Run a lead from the top of the MSD mounting bolt, to the fender.
Another thing-Pull the MSD plugs apart, and check to be sure the contacts are clean. Dielectric grease works well here.

LG

 

[hole]

Dave, let me state I have no experience with MSD. Many years ago I had a 77 FS Cherokee and a 78 F-350 give the same intermittent problem. Usually, both restarted after sitting awhile, but still frustrating nonetheless. The Cherokee ended up being an issue with a factory connector from the distributor-PCM loosing contact, and direct butt splicing took care of it. The F-350 ended up having an issue with a connection in the distributor, and a new distributor took care of it. Both took many many months to track down because of the infrequency and lack of being able to duplicate the problem in a shop setting and damn near got sold for scrap because of it. I cant tell you how many hours it took myself, multiple reputable mechanics and even the dealer out of desperation (who insisted it was the PCM and changed it 3 times on their dime and didnt solve the problem), but painstakingly one thing after another got crossed off before the culprit(s) were found. I hope your's is an easy one!

 

[hagar]

Being that it was running fine with no electrical issues before the engine mechanical issues occurred, I would be looking at electrical items/anything that was removed or unbolted for engine repair access.
Carefully grab wires and gently tug on them at the rear of the connector(s) to see if the wire is loose or pulls out.
It might not even be on the engine, just in the compartment.
Think what was unbolted/removed and set aside or out of the way ?

 

[hagar]

With the engine idling you could also start wiggling connectors around to see if you can make it stall.

 

[garagesss]

msd is a great product, I've never heard of problems. unless you reverse positive with negative. check all the connections maybe something oxidized, or a cable stops with vibrations. are the spark plug and distributor cables new?

 

[PistolDave]

This may sound silly, but years ago I had an 86 ford ranger that did exactly what you described for over a year. It would run fine for weeks, then with no warning the engine would just die. After sitting for a while it would start right back up. The problem turned out to be a loose terminal on the battery. Why it would run most of the time and then just randomly die I have no idea, but after I tightened up the battery terminal the problem went away for good.

 

[BusaDave9]

I have replaced the coil and it's been running good.

Sorry I should have posted sooner.

I also installed a big K&N air filter.

 

[Belizean]

I have replaced the coil and it's been running good.

Sorry I should have posted sooner.

I also installed a big K&N air filter.

We know you were just testing it !

 

[hole]

That filter is going to make Lumpy very happy!

 

[Lumpy Grits]

No secret-I hate K&N A/F's.
Nut'n filters better than paper does.
PLZ do the research-
Fingers crossed it's fixed!
LG