running rich on one side?

[libraryboy]

was wondering if anyone else has had the problem of running rich on one side? I have a single pierburg on top of standard intake manifold which feeds both sides of a 1.9 watercooled lump and have found it has started to run really lumpy.took the silencer of to stick on some new gaskets and found the n/s pipes where coke'd up but the o/s was clean. have recently rebuilt carb,servo pipe,coil,timing,leads,plugs,hoses.
anyone?

[kevtherev]

It's more likely that WBXers run weak on the left (3 & 4)
One possible reason for an imbalance is if the vacuum brake servo pipe is leaking air and or there is a gasket failure on either of the intakes on the manifold in my opinion.

Coking up may even be broken ring or ring wear.
how do the plugs look after a high speed run (over 3000 rpm for a coulple of miles) ?
tested the compression?

[libraryboy]

manifold gaskeys are the last to be changed..any idea where they can be got? or am i back to the kelloggs cornflakes

[kevtherev]

I think baxter does them

[Ian Hulley]

To check for the manifold gasket leak with the engine running spray WD40 round the gasket and listen for the engine revs picking up on their own *

*This advice given to me t'other week couresy of Steve Mocki (on mine it was the vacuum elbow that was loose)

Ian

[jason k]

yup what they said. it cant be rich on one bank its the same carb feeding both!!

gotta be an air leak

[libraryboy]

I agree with all.
first thing i did was used a can of carb cleaner (more combustible) and drowned the whole lot but found nowt. have read on vzi of similar prob and turned out to be dizzy and vacumn at fault also second chamber in carb not opening. luckily i picked up a dizzy at bustypes so gonna swop and report back.
has anyone stripped a vacumn of the side of a 1.9 dizzy? can it be done ?

[silverbullet]

has anyone stripped a vacumn of the side of a 1.9 dizzy? can it be done ?

Well they have to be assembled originally - usually the vac actuating arm is hooked onto the points baseplate. It is meant to be seviceable as the diaphragms do split with old age/high miles etc.
Had one go on my old V8 Rover and it took an age to find. Couldn't get the mixture right and the carbs wouldn't balance. New vac capsule and right as rain

[libraryboy]

good news !!
after swapping the dizzy and re timing its running spot on. i guess that after changing the servo hose ( with timing set to compensate the prob ) it just escalated the running probs .so with a change of dizzy and re-timing it has sorted it. just gotta strobe it now and then leave it alone.
has anyone had any advantages after altering dwell angle back or forward ?

[CovKid]

If its manual points, you set dwell to basically give you a longer service life between adjustments. if you're talking about timing, too advanced and it will predetonate (or pink), too retarded and it'll run like a slug. You can can also get overheating or lack of power probs if its not adjusted correctly. My years on v-dubs say you adjust advance until it just doesn't pink and then its right for your engine but by the book is fine.