1985 FJ60 5-speed swap successful - but the next day it won't start

[Dave L]

hi all,

So after a bit of cursing and the use of five jacks I was able to get the H55F up in, and the cross member in place - it started fist time and drove around the block - all good!

then the next day I can't start it. battery feels low. jump pack low too. charge & swap it for the spare, that won't start it either. it grudgingly turns over but doesn't catch. Charging makes no difference.

I figure maybe it's a battery problem and get another - it turns over better and almost catches, almost.

I check the ground connection - clean up the contacts. check the connections to the starter and clean those contacts

no spark when I try a spark plug lead to the block or a tester with a bulb

check the coil ohms - they are 0.7 across the little ones and 11,200 from the big one to one of the little ones.

Holding my finger over the coil lead when turning over gives me no shock

coil is getting 12V

open up the box on top of the coil and every contact inside gets 12V

coil is constantly outputting 12V

Getting pretty despondent - any help diagnosing this would be greatly appreciated

 

[jclark]

There are definitely smarter people here, but at first blush sounds like a faulty ignition coil, possibly the distributor. Are you on points?

 

[DrRock]

I would check all of the ground bonding straps that go to the engine. Also, re-seat of the connectors such as spark plug wires, coil wire. It sounds like you did the swap and left the engine in. If so, I would look and see if any wires got stretched during the install too. I recently did this on my 1985 too but I installed the whole drivetrain complete as I was also installing a new engine.

Cheers, James

 

[OSS]

Sometimes... coincidences do happen - and I think that the engine problem you're having now has nothing to do with the new transmission. It's just a dumb gearbox.
Since you've identified a dead coil - definitely replace it.
The ignitor (aluminum box) that's bolted to the top of the coil, serves the purpose of amplifying the faint signal from the hall-effect sensor/pickup in the distributor. If the ignitor went dead (very rare) you wouldn't get any spark at all.

 

[Dave L]

Sometimes... coincidences do happen - and I think that the engine problem you're having now has nothing to do with the new transmission. It's just a dumb gearbox.
Since you've identified a dead coil - definitely replace it.
The ignitor (aluminum box) that's bolted to the top of the coil, serves the purpose of amplifying the faint signal from the hall-effect sensor/pickup in the distributor. If the ignitor went dead (very rare) you wouldn't get any spark at all.

Thanks OSS - the tips you gave for replacing the transmission really helped. I didn't follow all of them, but when it was in I understood where you were coming from.

You really think that I should replace the coil? What other diagnostic could I perform before confirming this?

The ohms tests on the coil itself seemed to suggest that it's ok so could it just be the ignitor?

If I'm getting a buddy to try the ignition and sticking my finger on the coil contact with no shock is that a definitive answer that the coil or igniter are bad?

many thanks

 

[OSS]

Check the ENGINE fuse in the fuse panel in the cab. It might look ok but check it with an ohm meter to make sure its not burned out.

The coil output lead has to jump to ground to spark. Either to a piece of metal on the fender or the engine block. Its not going to shock you if you're not grounded to the car - and I definitely wouldn't recommend trying that,

 

[Dave L]

Check the ENGINE fuse in the fuse panel in the cab. It might look ok but check it with an ohm meter to make sure its not burned out.

The coil output lead has to jump to ground to spark. Either to a piece of metal on the fender or the engine block. Its not going to shock you if you're not grounded to the car - and I definitely wouldn't recommend trying that,

It was the ground strap - I only ever had it strapped to the frame. never knew it should go to the block - thanks OSS!

 

[Dave L]

I would check all of the ground bonding straps that go to the engine. Also, re-seat of the connectors such as spark plug wires, coil wire. It sounds like you did the swap and left the engine in. If so, I would look and see if any wires got stretched during the install too. I recently did this on my 1985 too but I installed the whole drivetrain complete as I was also installing a new engine.

Cheers, James

it was the ground strap - I had it running to the frame. I guess when i put it all back together after the engine rebuild i couldn't remember where all the bits went and figured the frame was a good place to put it - hooked it to the block and it fired right up - thanks Dr Rock

 

[Spike Strip]

Replace that old worn crap ground strap with a heavy duty one or a 2/0 cable.

 

[DrRock]

Brilliant, great so see you got this sorted!

Cheers, James