Running problems, help!

[K@rlos]

I was driving my bus last week and it was fine, but then started to feel sluggish then finally cut out on the A12, not good. It restarted but now runs crap! It will start, idle & rev up fine but the moment you try pulling away it either bogs down popping and banging or just cuts out. It starts again ok but will keep doing the same thing every time I go to move.

I've changed the points & condenser, dizzy cap and HT leads. I've also blown the carb and fuel line through with an air line but still the problem persists so I'm now abit boggled. Wondering if it's a naffed coil or if the timing is out but I can't check it a my strobe light is fooked.

Any suggestions greatly appreciated.

Karl

 

[chicargo]

hi fella, did you try changing the spark plugs, one plug may be weak ???.

 

[K@rlos]

hi fella, did you try changing the spark plugs, one plug may be weak ???.

Hi mate

No I didn't, did think that but their only about 6 months old so I sorta ruled it out :-/ I fitted a carb rebuild kit a couple of weeks ago so am thinking that it may not have sealed properly?

 

[flynster]

found that coil Karl its ready and waiting

 

[K@rlos]

found that coil Karl its ready and waiting

Cheers Steve! Graeme said he'd stop off and get it for me. I owe you a pint

 

[71Westy]

Karl,

That could also be timing or a manifold leak. If you've changed the points, then it won't be the gap.

It didn't pop the backfire plug from the carb did it?

Nick

 

[sparkywig]

I went through 3 sets of plugs before I sorted a misfire, so it could be a bad plug. Although it does sound like a timing issue.

 

[K@rlos]

Nick, that's the plate the size of a 5p on the carb body right? If so, no it didn't.

Simon, yeah I'm thinking timing or a duff a weak coil. The reason I think coil is because whist rewiring the bus I left the ignition on for ages and the coil got really hot, so hot in fact I couldn't bare my hand on it :-/ so I'm wondering if it's finally hand it.

 

[sparkywig]

The coil insulation could've broken down if it got that hot.

 

[K@rlos]

The coil insulation could've broken down if it got that hot.

Yeah, which would result in a weak spark right?

 

[sparkywig]

Yes

 

[K@rlos]

Well I fitted coil tonight that Oroo kindly gave me and still the problem persists >:-( the engine starts first time, idles lovely and revs up clean but still whenever I pull away it losses power then pops, bangs and stumbles badly. It must be carb/fuel supply related, so back to the drawing board.

 

[sparkywig]

Check the timing and/or plugs, if it revs cleanly not under load it can't be a fuel problem.

 

[K@rlos]

Check the timing and/or plugs, if it revs cleanly not under load it can't be a fuel problem.

That's very true. I'll clean and gap the plugs, then check the timing.

Cheers Si

 

[ZedBed]

What you describe is what ict's do when you get them with too small idle jet, so don't discount fuel.
Does sound electrical though.
I cured similar prob once after running it it the dark - HT tracking across the coil to the -ve coil terminal.
Same with a MK1 transit - HT leads like fairy lights.
Same with another car - split distributor cap - HT tracking round the outside along the crack for some reason.
Darkness can be your friend.

 

[K@rlos]

What you describe is what ict's do when you get them with too small idle jet, so don't discount fuel.
Does sound electrical though.
I cured similar prob once after running it it the dark - HT tracking across the coil to the -ve coil terminal.
Same with a MK1 transit - HT leads like fairy lights.
Same with another car - split distributor cap - HT tracking round the outside along the crack for some reason.
Darkness can be your friend.

Well I initially thought fuel related because as you say the symptoms are like when twin carbs are too lean, had that trouble with my old IDF fed motor. Well the carb is spotless and the ignition system appears sound, just the plugs I've not checked yet.

 

[71Westy]

Karl,

I'd still go for lean mixture - perhaps through an inlet /carb leak - as my first bet.

Have you tried the squirting around with carb cleaner trick?

Nick

 

[K@rlos]

It is fixed. Was the distributor, don't think it was advancing properly. Fitted another dizzy, checked points and timed up. Drives lovely! Thanks to you all for your help

Karl

 

[ZedBed]

Result!