Mv2.1 grotty idle

Post by **john.e** » 26 Nov 2005, 17:59

The bus (2.1Mv, single DCNF 40) has just developed a grotty idle? Will idle for a few minutes then rollover. During the time it is running it hunts up and down the rev range before finally giving up the ghost.

Couple of weeks ago chokes jammed on carp from unkown source and since carb strip and clean won't idle happily. New gaskets, seals & needle jet/seat fitted to carb. Float set to 52mm just closing.

Other work done... Timed @ 30BDC @ 3000 rpm, new points @.45mm, new dizzy cap, rotor arm, new leads, new plugs gapped @ .7mm. also moved all the leads and plugs about to no avail?No 1 pot keeps missing @ low revs. Just performed comp test and got the following...

No 1 @ 140psi
No 2 @ 150psi
No 3 @ 155psi
No 4 @ 150psi

Applying +-10% appears to be in tolerance but! could this be the root of it. Identified problem firing by pulling plug cap on each pot, No 1 resulted in no change.

Any ideas please.

Post by **Kermit** » 26 Nov 2005, 18:33

Have you got a spark on number 1 sparkplug?

kerr

Post by **john.e** » 26 Nov 2005, 18:38

Have you got a spark on number 1 sparkplug

Good question but not the problem, got a loverly fat one, spark that is. Tis stable too as used inductive strobe on No 1 lead when setting timing, no hint of drop out. Tis this thought what led to swapping dizzy cap, rotor and moving leads and plugs around to confirm is OK.

Post by **Kermit** » 26 Nov 2005, 18:59

umm, good spark, ok compression and timing is spot on then only thing left i suppose are fuel and air, back to that carb I suppose??

I know you mentioned the sparkplugs are new, but are there any deposits on the plugs yet, to determine if its running too lean etc,etc

Kerr

Post by **john.e** » 26 Nov 2005, 19:44

Ah ah, knew there was summut I forgot. No 2, 3 n 4 were a nice light brown/grey colour. IIRC means good mix but No 1 was black and sooty, though not checked since todays tweak and thrash!! Can't decide if just unburt fuel building up or summut else. Appear to be no oil in zorst though (no blue grey plumes or oil smell)??? Also carb is on stock manifold that has had wall welded into it to split manifold, left barrel to pot 3 n 4, right barrel to pot 1 n 2. Oh yeah, steam @ fire up, clears after few minutes!

Current ideas... Head gasket/cracked head n water supressing firing? (but reasonable comp test) or Valve guide/stem seal failed so small oil ingress?

Post by **john.e** » 27 Nov 2005, 17:18

Just checked for leaks on inlet system and can't find any so looks like top end off. Any one tried this in situe? Looks possible according to Mr Haynes but fiddly? Any advise before I rip it down?

Post by **T'Onion** » 27 Nov 2005, 18:57

Sorry John only just seen this on here, been replying to your other post on BG...

When Andy and I did my 1.9dg (blown head gasket on the general lee), I had no choice but to do it with it in the van.

its a pain but we did it, unless you have too try and keep the pistons in the cylinders, mine had be bodged together with gasket goo so when i pull the head off the cylinders came off with it.

You can replace the seals with the cylinder still in,slowly rotate the engine so the piston your working on is at the top,the pull the cylinder just enough to replace the bottom seal,

personaly if i were to have to do it again i would take the whole thing out

Good luck mate...

Post by **john.e** » 27 Nov 2005, 19:04

Cheers Mr Onion. Just posted on BG, gonna be a roadside repair, uck!!!

Post by **skell** » 01 Dec 2005, 19:03

is this what you were looking for garage space for? if yer van were to fit in my garage there should be enough headroom to jack it up to drop the lump

When I replaced my engine at the end of the summer I found a small veedub garage in crowborough to drop the old engine out for me, I took it away swapped ancillaries and so on and took back to have new lump lifted into place and timed/tuned up. cost me 300 notes, but without timing/tune up would be a bit less.

Post by **john.e** » 05 Jan 2006, 11:25

Just to bring this upto date in case it helps others. Following a load of odds'n'sods the beast appears to be happy again but the final clincher was to clean the idel jet ports a 2nd, 3rd and 4th time!!!

Ripped down the entire carb, replaced gaskets, seals, all manifold gaskets, chokes balanced, jets checked, emmisions tweaked, point, dizzy cap, plugs, timing and still it ran like a pig until... the above mentioned 2nd, 3rd and 4th blow through of the idle jet ports.

So if at first it don't work, just try again

I can only assume that there was grto buried deep int he airways and fuel paths that took time to work loose and clear completely.

P.S. Skell, sorry I have not replied earlier, only just seen the offer, and very generous one it is too. Cheers fella though I hope it will not be needed now. Hows your gem going anyway, good I hope? Have you gone back tot he office yet, been very silly here as rolling out SIMS and what a pig it is to get running first time round, think 'tis time to rename Capita to Crapita

Post by **skell** » 05 Jan 2006, 13:27

yup back at work, so more time on here!
Sometimes wish we bought in a student records system, we roll our own on sun/oracle. I'd rather be painting the forth bridge! But I just got promoted so can't be going too wrong, but now get to do the work of 3 people instead of just 2!

I'm in the land of carb stripping and rebuilding and rebuilding and rebuilding, will be giving the jets many cleans this weekend to try and get on top of it. But apart from a littel stutter she's running better than ever.

PS just wondered if I'd get a lowered wedge in me garage for future reference like...