Need help! Weak spark.

[vping]

Just about started but won't. I pulled a plug & checked my spark. It is weak and after about 8 sparks, no more spark. What could this be?

 

[Deleted member 3577]

Dang......Can't go very far on 32 sparks, now can ya?

My WAG is coil.......How much of the ignition system are you sure works?

 

[ccougill]

what kind of ignition do you have, points, petronix, crane/allison?

 

[Deleted member 3577]

I always say coil......(or control box, if it's a charging problem)

Cause I'm very suspicious of the goings on, inside these Lucas "black boxes"..

 

[ccougill]

ahhh, but it could be the condenser if using points, or maybe the points aren't opening. also, what are your plugs gapped at? points systems use a narrower plug gap than modern electronic ignitions

 

[Deleted member 3577]

Vping has 5 British cars......(God bless him)

I'm assuming it is something bizarre & confounding.

Nothing is as peculiar as an intermittent coil or amplifier problem.

 

[ccougill]

and I thought I was nuts, I only have two. But I agree, ignition problems are often a poser

 

[DrEntropy]

Agreed. Electrons are ~supposed~ to behave logically. Unfortunately the bloody 'widgets' the electrons pass thru on their way to the buisness end (the firing widget) are very fickle with regard to "logic". Coils are among the worst offenders. Followed by condensers.

 

[Deleted member 3577]

Quote: there's a fine line between "hobby" and "mental illness" /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/thirsty.gif

 

[DrEntropy]

We prove that theorum daily.

 

[vping]

Stock ignition & Plugs are gapped @ 032.
I changed the points & condensor & got a better spark. Probably need to adjust the points but need to check the book on how.
CHOKE HELPS!! duh it's been a while.
Runs pretty **** good if I do say so myself. 50PSI on the OP @ 180ºF.
Little run on after I turn her off and a bit of a pause when I restart as if the battery is not giving enough to start but it is new. Wonder what that is.
I really should rebuiuld the SU's.

 

[ccougill]

could be timing

 

[DrEntropy]

run-on and hesitant start is likely due to timing issues. Plug gap may be a bit wide for a points type iggy tho. .028" would be my choice there.

O/P is good, temp is steady at 180? That's good too.

 

[Deleted member 3577]

Elva's MGA engine LOVES the NGK BP6ES plugs gaped at .035 w/ the 40,000 volt coil + Pertronics.

The standard 17,000 volt Lucas likes .025-.028 for a plug gap.

Also....I run 16 degrees static & 30 full in, as far as timing goes.
30 sounds like a lot but, B series engines like it. /ubbthreads/images/graemlins/yesnod.gif
(If it pings buy super93 or back it off 2 degrees at a time)

And run the dog snot out-a it /ubbthreads/images/graemlins/grin.gif

 

[piman]

Hello Vping,

the plug gap should be 0.025", check that the coil polarity is correct. Points gap should be set to 0.015" and if you have a meter do a voltage check from the coil to earth with the points closed. You should have about 12v on the +ve terminal and 0.2v on the -ve terminal much more than that on the -ve then there is a bad connection between the coil and the distributor.

Alec

 

[vping]

The plug gap was another thread that I thought I had nailed down. Book states .032 as stock. Should I still change it?

https://www.britishcarforum.com/ubbthread...rue#Post196950.

2 things to do tonight are:

Check points gap.
Check timing.

It the overall concensus to change SPG to .030 - .028? even though it's a stock iggy? (disregard Bentley?)

How much will the wires play in its running. They were just replaced when it was parked.

 

[kennypinkerton]

New wires should be fine. But if you suspect them, get the car running at night, and if they're microcracked you get to see the prettiest lightshow you ever thought of in a car. If no pretty blue streamers along the wires, then they should be fine.

Make sure you haven't pinched the internal wire (on the points - the cloth covered one) between the distibutor and the cap... It's easy to do and causes weird problems. Also that you have the little plastic washer in the correct place (the one at the end of that same wire where it bolts down).

 

[vping]

I reinstalled the cap and the cloth covered wire as was the original. I removed the nut & then the plastic washer, added the cap and cloth wire, then replaced plastic washer & the nut.
I checked for any pinching and it was ok.
Before I look it up, what is best way to adjust the points.

 

[Naomi]

I don't have an answer but I'm sure gonna watch this post since my 79 has broke down twice due to the ignition---in a month's time /ubbthreads/images/graemlins/frown.gif

 

[vping]

Need help again. Ran fine last night & 22 hours later, I try and start it after work. Spark is weak to nothing.
I am going to try and change the gap.
PIMAN, email me with the specifics on the meter settings to check the coil.