Pesky Misfiring Pinto

[Guest davidimurray]

Know we have a few pinto experts on here so any thoughts gratefully appreciated - save reposting everything here, the details of my troubles can be found here http://www.locostbuilders.co.uk/viewthread.php?tid=189605

[blue]

Ok having read your other post I think it's time to go basics !!

Do you have a standard carb and manifold to try.

Also have you took the tops off the carbs and checked that the needle still has the circlip on it cos your post sounds like your running lean on one cylinder hence the AFR on your wide band has gone from 12s to 14.

You say the slides are all moving but not that the needle is moving with it

[Guest Chris Russ]

Can I suggest you re-check your valve timing as well, My Pinto 2.1 managed to 'jump' a tooth & caused all kind of weird issues with misfiring & fuel mixture!! .....took me ages to find it, having checked everything else first!

[Guest peter2b2002]

check any gaskets might have a small leak when hot

peter 2b

[Guest mower man]

As said basicsand then the head scratching starts ,1 afr at 14 is good ,2 have you checked tappets,3 are you running std plugs ,I ask as I had a drama with a set of 3 electrode plugs having th the gap closed by minute piston contact [ head has been worked ] ,4 rotor arm dizzy cap ,leads ,coil packs ,5 float hieghts on all carbs ,I leave it at that for now mowerman

[Bob Tucker]

Not just valve timing, but valve clearances too.....it could be valve recession, or cracked valve seat closing the gap.

[Guest davidimurray]

She lives

 

Valve timing and clearances all checked and fine.

 

Prize to blue for setting me on the right path. Whipped the diaphragm assemblies out of 1 and 2 and noticed that no2 needle was sticking out further than the other. Stripped the needle and found the spacer washer under the circlip missing. Found one in my box of spares, fitted and all good.

 

Mystery is how has it been fine since I last touched the carbs 200 miles ago?I can only think I missed refitting it and the circlip has been sat on the ledge all this time until it dropped down?

[blue]

Glad to help. That's what this clubs here for !!!