Dies randomly while driving (1 Viewer)

[Plantman]

For months my Cruiser has been randomly shutting off while driving. I have not been able to predict or replicate it when I want to. When checking things without actually driving, everything seemed normal. Last week it died entirely and has no spark.

It’s a 1977 FJ40, 2F, MSD6, Mallory magnetic dizzy.

I replaced the coil, tested the MSD box, tested the ballast resistor, found some corrosion on the contacts in the dizzy (looks like it got moisture inside, not surprising since I don’t have inner fenders). I cleaned the corrosion off. After doing all this there’s still no spark. Any ideas or similar experiences? I’m wondering if it’s a broken wire somewhere or if somehow the MSD box is not working properly even though it seems fine when I test it (basically just firing a spark between ground and the end of the coil wire).

 

[ceylonfj40nut]

Check your idle control solenoid, assuming it is an aisin carb

 

[pithicus]

Could be a faulty magnetic module in the dizzy. The 2 wires coming from the pickup module should have a resistance reading. Should be around 700 ohms.

****The above is for some model pickups, others say 50 to 150 ohms is normal, depending on your model. So open circuit or dead short would mean it's no good.

 

[DougAustinTx]

Could be a faulty magnetic module in the dizzy. The 2 wires coming from the pickup module should have a resistance reading. Should be around 700 ohms.

****The above is for some model pickups, others say 50 to 150 ohms is normal, depending on your model. So open circuit or dead short would mean it's no good.

Make absolutely certain that your ignition coil/ignitor assembly is fully grounded or it will not spark, at all. On my '79, everything looked good and the two bolts holding the ignition assembly to the inner fender were in place, but apparently there was rust or corrosion on the bolts to the point that it could not get a good ground. I put a temporary jumper wire from the coil bracket to a clean bolt and got perfect spark. Took the two coil assembly mounting bolts off the inner fender, cleaned the bolt threads and the inner fender and solved the issue.

 

[Green Bean]

We had a similar problem: Turned out that it was a lose connection at the ignition wire plug behind the dash. It was difficult to diagnose because of the intermittent way that it would present itself. You may want to check wire terminals under the dash working your way toward the engine bay to ensure that everything is tight and no shorts. Best wishes.

 

[85roktoy]

I had a similar issue recently and have the same MSD box. Tested everything it ended up being a bad ignitor in the distributor. Friend of mine who works on race engines said those boxes are pretty bulletproof. Good luck

 

[72LANDI]

I recently had a similar issue with a new out of the box D.U.I. It turned out the 12V + female lead that plugs into the D.U.I. was defective and was making intermittent contact with the male lead.

 

[Plantman]

Check your idle control solenoid, assuming it is an aisin carb

Forgot to mention, It has a Weber 32/36. I wish it had the factory Aisin.

 

[Plantman]

Those are all good suggestions. I’ll check all those things and see what happens. Definitely wouldn’t have thought of some of them. Thanks for the help! I really appreciate it, especially since I’m trying to get the thing running during finals week and moving because I graduate.

 

[Plantman]

We had a similar problem: Turned out that it was a lose connection at the ignition wire plug behind the dash. It was difficult to diagnose because of the intermittent way that it would present itself. You may want to check wire terminals under the dash working your way toward the engine bay to ensure that everything is tight and no shorts. Best wishes.

Did this cause you to lose power to just the ignition system or all systems connected to the key switch. I have an electric fuel pump that will still run even when there’s no spark.
This thing had a lot of non-factory equipment on it when I got and I haven’t worked out all the bugs from the previous few owners (who may or may not be my dad and grandad...).

 

[pjohnson]

@Plantman Not sure where you are in Idaho, but you could try posting over in the Treasure Valley clubhouse forum. There's a few Cruiser experts around here.

ID- Treasure Valley Land Cruisers

forum.ih8mud.com

 

[Plantman]

@Plantman Not sure where you are in Idaho, but you could try posting over in the Treasure Valley clubhouse forum. There's a few Cruiser experts around here.

ID- Treasure Valley Land Cruisers

forum.ih8mud.com

I'm over in Rexburg. I'm guessing everyone on the Treasure Valley page is in the Boise/Treasure Valley area?

 

[pjohnson]

I'm over in Rexburg. I'm guessing everyone on the Treasure Valley page is in the Boise/Treasure Valley area?

Mostly, but many from outside the valley also, at least one LC semi-guru in Mtn. Home.

 

[Plantman]

Mostly, but many from outside the valley also, at least one LC semi-guru in Mtn. Home.

You must be talking about Eric.

 

[Tooth Fairy]

definitely Eric.

 

[Tooth Fairy]

I’m not responsible for anything my dad did.

It ran fine when you were 2. What’s the problem?