I'm using a nippon-denso electronic distributor with internal ignitor and GT40 coil on my 5k and it seems to be running on 2 cylinders. When you pull the plugs lead off the miss-firing cylinder hold it close enough for the spark to jump from lead to plug that cylinder fires up again. The problem began when I removed the dummy carby and manifold I was using for the twin solex's.

 

Wierd shit. The timing is correct. It's been checked more times than i've had wet dreams. I have traced the problem down to the distributor. I've swapped leads, coils, plugs and swapped out the distributor for another and the problem persists. I think I may need to regraph the distributor due to the cam before I ever get it running on all four.

 

Does anybody know what other issues would cause the engine to run on 2 cylinders?

 

I also found this on my search for the answers. Looks interesting though probably been seen here before. A electronic replacement for breaker points in distributors

Hot Spark

Edited April 21, 201115 yr by GJM85

is the coil output lead arking out on any of the terminals on the coil?. is the dissy shaft bent and not running true?

New coil and new leads and i've used to difference electonic distributors with the same result.

tried swapping/new plugs? how many earth straps do you have on the engine?

 

 

arent you running monster compression? i say go for a thrash

New coil and new leads and i've used to difference electonic distributors with the same result.

Sounds like you have eliminated the ignition system

So I would be inclined to check you haven't lost a couple

of cam lobes.Sounds like a very similar problem i had with a 5K

5k a while ago.

Sounds like you have eliminated the ignition system

So I would be inclined to check you haven't lost a couple

of cam lobes.Sounds like a very similar problem i had with a 5K

5k a while ago.

 

Compression is pretty whacked. Between 125psi and 135psi on cylinders 1,3 & 4 but down at 110psi on number 2.

I've cranked the engine over repeatedly by hand when doing the timing. All the rocker gear appears to be functioning. What gets me is the part where if you remove the number 2 and 3 leads while its running and hold them close enough to the spark plugs for it to arc across they start firing properly. This is what leads me to believe its an ignition issue.

Maybe, and I do say maybe, check the crimp connector on the end of the lead. I had that problem and as soon as you put pressure on it they work just fine, even with brand new leads. And as well check that when you clip them onto the spark plug that the little metal end bit is secured and not loose.

 

I'd check the earth's as well.

 

You definately have a weird problem though, let us know what it is if you do find it.

Really stupid question, you do have the plug leads in the right order?????

 

I'd be pulling the rocker cover to recheck if the valves are opening, and if they are, opening when they should be. Whip out the plugs and earth them to the block. Crank the engine to see if each plug is actually firing.

 

Had an issue like this with aftermarket leads. Was misfiring on a couple. Put standard leads back on and all was sweet. But the red ones looked so good...... :sob:

are you running the twin solexs or std carby?

Maybe, and I do say maybe, check the crimp connector on the end of the lead. I had that problem and as soon as you put pressure on it they work just fine, even with brand new leads. And as well check that when you clip them onto the spark plug that the little metal end bit is secured and not loose.

 

I'd check the earth's as well.

 

You definately have a weird problem though, let us know what it is if you do find it.

 

I'll check all the earths. I swapped leads around a couple of times. I might just get some better quality leads and ditch the bosch one.

 

Really stupid question, you do have the plug leads in the right order?????

 

I'd be pulling the rocker cover to recheck if the valves are opening, and if they are, opening when they should be. Whip out the plugs and earth them to the block. Crank the engine to see if each plug is actually firing.

 

Had an issue like this with aftermarket leads. Was misfiring on a couple. Put standard leads back on and all was sweet. But the red ones looked so good...... :sob:

 

All the plugs are firing. The leads are just standard bosch items.

 

are you running the twin solexs or std carby?

 

I'm running the twin solex's. Initially running far to rich it would turn the garage into a fuel bomb after 2 minutes of idle. we rejetted the mains from 135's to 115's.

 

Could I possibly have wired the distributor incorrectly? There are 2 wires on the dizzy, black and black & orange. I hooked up the original dizzy wire from the lume to the black and ran a line from the black and yellow to the positide of coil. I can't even get it to fart if I hook it up any other way...

the two wires go straight to the coil.

 

black = neg

black and orange trace = postive

Maybe check also a blown head gasket between 2 & 3

between the cylinders only, not water jackets.

have you put the standard carb back on just to eliminate

The twin sidies ?

the two wires go straight to the coil.

 

black = neg

black and orange trace = postive

 

ok. I'll try hook it up that way. Hopefully I haven't already fried the dizzy.

 

Maybe check also a blown head gasket between 2 & 3

between the cylinders only, not water jackets.

have you put the standard carb back on just to eliminate

The twin sidies ?

 

I haven't swapped the single carb back over yet. I was hoping to nut this out with out it. If I can't, i'll pull the head off and check the pistons and valves.

It seems to me that most answers to this question are still missing the main point of interest!When he removes the lead from direct attachment to the plugs and just holds them in a near vicinity so that the spark can jump,everything is ok!

I'm not overly mechanically inclined but it seems to me then that the issue has to be either faulty leads,some sort of issue with the plugs in those cylinders or some sort of short between plug and lead when in contact with each other.

Forgive me if I sound uninformed and overly simplifying the issue,I just can't see how carbies/manifolds/cam lobes etc can be the issue when it runs perfectly under the described test situation.

Hope you all have a good easter.

don't pull the head off yet!

 

 

what is the dwell set on the electronic dissy? should be around the 42 degree mark

 

anything less will cause the coil not to charge up enough and give a weak spark