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Model specific boards => Golf mk2 => Topic started by: leeroy20vt on 11 September 2009, 17:07

Title: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 17:07
hello boys and girls after a bit of advice just got my conversion running apperently engine been standing for a number of years

when first started all seems good bit rough on tickover but thats all give it a few revs and let it tickover agin it begins to smoke then if u rev it again u get loads of smoke  :angry:

also noticed that only one carb seems to be running on tick over if u put ur hand over carb that is inline with 1 and 2 it trys sucking ur hand in but 3 and 4 hardly anythink

and if u take plug leads of 3 and 4 it doesnt make a difference at all until u try reving it

could this be a sticky/bent valves or oil seals

or am i barking up the wrong tree here


any help would be great
lee
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 11 September 2009, 17:29
chould be meany things.

pull the plugs first off, and comapre them,   then do a dry compression test followed by a wet compression test.

it's more than likely going to be a head off job.  the missmatch pulling of air choudl just be really badly set carbs.  but the smoke is the worry, if it's comeing from 1 cyl  it's proaby piston if it's a pair it more likely to be head gasket. 

the loads of smoke when revving shouts piston to me.  possobly just stuck rings possobly hole
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 17:43
thats not good then  :cry: :cry: :cry: :cry:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 11 September 2009, 18:39
smoke on startup = seals.   smoke when  reved / loaded normaly  = metal :(
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 18:51
could it be just rings if so could i put new ones in or will other work have to be done
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 11 September 2009, 19:18
if the engine has been sat long enough the rings can stick, 

sometimes it's possibel to free them by putting siesel int he cylinders and letting them soak for a bit but your best off lifting the head  dropping sump then it's only a few bolts and you can pop the pistons out.   glaze bust the bores and refit pistons with new rings 

( yup it is easyet to say than do )

if you do find a phucked piston it's not the end of world tho,  got a box of random assorted pistons in the shed :)
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 19:32
cheers danny_p
when u say a wet and dry test wat do u mean m8
i will do a comp test tomoz
Title: Re: smoky jo 20l 16v on twin 40s
Post by: l333 on 11 September 2009, 22:26
hi dry compression check is remove plug and wang it over with throttle open best to isolate fuel supply first. wet is the same but with a bit of oil in the bore to help seal the rings. if you get a big difference between wet and dry then you no its prob rings but compression check dosent normly show an oil control ring fault

smoke on startup = seals.   smoke when  reved / loaded normaly  = metal :(

but as said this should give you a good indication as to the smoking
Title: Re: smoky jo 20l 16v on twin 40s
Post by: DarnPB on 11 September 2009, 22:27
If the car has been sat for a number of years, then what are you going to expect? I would get both carbs running properly, then run it hard and get the loose carbon out of the system. Carbon bakes onto the components such as exhaust ports in the cylinder head, the valves and the pistons. But the carbon will soften up and become flakey and burn off with use. This will be the cause of your smoke.
If you think the rings are stuck in their grooves then try, as said before, pouring a little diesel into the bores or some brake fluid and leave to soak over night, then again, run the engine hard and get some heat into it.
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 22:30
cheers guys when u say a little deisel or brake fluid would u say a cap full down each bore will do the trick
thanks again i hope its nout major
Title: Re: smoky jo 20l 16v on twin 40s
Post by: VW BUSH on 11 September 2009, 22:43
cheers guys when u say a little deisel or brake fluid would u say a cap full down each bore will do the trick
thanks again i hope its nout major

You might need the red one a bit longer eh :wink:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 22:46
cheers guys when u say a little deisel or brake fluid would u say a cap full down each bore will do the trick
thanks again i hope its nout major

You might need the red one a bit longer eh :wink:

red one ??
Title: Re: smoky jo 20l 16v on twin 40s
Post by: VW BUSH on 11 September 2009, 22:52
cheers guys when u say a little deisel or brake fluid would u say a cap full down each bore will do the trick
thanks again i hope its nout major

You might need the red one a bit longer eh :wink:

red one ??

Red one wiv no door cards :wink:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 22:54
ar that one lol yer be ok once its moted so who are u then lol yimp ?
Title: Re: smoky jo 20l 16v on twin 40s
Post by: VW BUSH on 11 September 2009, 23:05
ar that one lol yer be ok once its moted so who are u then lol yimp ?

Yeah dude, many names on many forums its hard trying to remember them all
 :grin:

on topic

I would strip the rings out cos even if you free them up the oxidized metal and carbon build up could effectivly lap/score your bores.
As Danny P says sump and head off scotchbright the bores pistons and grooves, oh and clean out oil jets while you are there.
Cost a bit but better than taking it apart twice :smiley:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 11 September 2009, 23:09
ar that one lol yer be ok once its moted so who are u then lol yimp ?

Yeah dude, many names on many forums its hard trying to remember them all
 :grin:

on topic

I would strip the rings out cos even if you free them up the oxidized metal and carbon build up could effectivly lap/score your bores.
As Danny P says sump and head off scotchbright the bores pistons and grooves, oh and clean out oil jets while you are there.
Cost a bit but better than taking it apart twice :smiley:


well i chucked a bit of brake fluid down there tonite  and if it cures it then i do the stripp for sure as it makes snese i will alaso do a compression test on it tom and see what happens there aperntly had a new hd gasket it on it so shouldnt be that fingers crossed it dont cost to much lol
Title: Re: smoky jo 20l 16v on twin 40s
Post by: VW BUSH on 11 September 2009, 23:42
ar that one lol yer be ok once its moted so who are u then lol yimp ?

Yeah dude, many names on many forums its hard trying to remember them all
 :grin:

on topic

I would strip the rings out cos even if you free them up the oxidized metal and carbon build up could effectivly lap/score your bores.
As Danny P says sump and head off scotchbright the bores pistons and grooves, oh and clean out oil jets while you are there.
Cost a bit but better than taking it apart twice :smiley:


well i chucked a bit of brake fluid down there tonite  and if it cures it then i do the stripp for sure as it makes snese i will alaso do a compression test on it tom and see what happens there aperntly had a new hd gasket it on it so shouldnt be that fingers crossed it dont cost to much lol

Good luck :wink:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 12 September 2009, 13:05
been out today done a compression test cylinders 1 and 2 are low at 100 psi and 2 and 3 are at 150 psi also found that it had chewed the rotar arm to peices how it was still running not sure i have played with the carbs and it not smoking as much but there still isues me thinks
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 12 September 2009, 17:17
ouch,  those compression numbers are a bit to low  really need to find whats causeing the inbalance in readings and why,    Two cyls reading low is often headgasket, 100 is bad  but 150 is reall a bit low as well. but at least theer not knackerd piston low  :smiley:

as darn PB said   get some heat into it that'll help things get moveing  and see if the smoke will burn off, then do another CR test to see if the numbers come up.  and go from there
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 12 September 2009, 18:08
ouch,  those compression numbers are a bit to low  really need to find whats causeing the inbalance in readings and why,    Two cyls reading low is often headgasket, 100 is bad  but 150 is reall a bit low as well. but at least theer not knackerd piston low  :smiley:

as darn PB said   get some heat into it that'll help things get moveing  and see if the smoke will burn off, then do another CR test to see if the numbers come up.  and go from there

cheers fella
been driving it about today a bit and the smoke seems to come and go when it feels like it im getting a tiny bit of black smoke out of the breather but its not smoking no were near as much as it was on tick over and fook me it pulls like a train
i have messed about with the carbs a little and that seems to have made a bit of difference in the smoke to i will run it about tom and then do a nother cp test on monday


what should the figures be m8
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 12 September 2009, 19:04
a 10:1 cr motor wants to be pulling 12 - 13 bar under crancking really 180 - 200 psi is what it idealy should be
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 12 September 2009, 20:08
a 10:1 cr motor wants to be pulling 12 - 13 bar under crancking really 180 - 200 psi is what it idealy should be

ok m8 may well be worth have a further dig then as dont look good does it seems to be running a lot better now still little smoky but smells more fuel related now
Title: Re: smoky jo 20l 16v on twin 40s
Post by: danny_p on 12 September 2009, 21:08
as th emotors been stood for ages,  and seems to be getting better hopefully you should find the compression will come up
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 12 September 2009, 21:15
as th emotors been stood for ages,  and seems to be getting better hopefully you should find the compression will come up

fingers crossed a il keep u posted
Title: Re: smoky jo 20l 16v on twin 40s
Post by: Jay on 12 September 2009, 21:58
Hope you get this sorted, defo a cool build  :cool:
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 12 September 2009, 22:18
Hope you get this sorted, defo a cool build  :cool:

cheers fella cant wait till its running nice
Title: Re: smoky jo 20l 16v on twin 40s
Post by: leeroy20vt on 13 September 2009, 18:04
little update been playin with carbs and it seems unless the carbs are both pulling the same air it dont run properly which makes sense lol so got it as close as i could by ear seems much better

its not smoking much now only seems to be on tickover and smells quite fuely so im guessing it has the wrong idle jets in it ??

so its getting there  :smug: