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White smoke on start up overfueling

Posted: Sun Jan 22, 2017 10:56 pm
by evolve123
Hi All
I wondered if anyone could shed some light on a problem with my sj.
it smokes like mad on start up and when idling. has a misfire when it warms up and is soaking the plugs in fuel.
Its a 1.6 8v vitara engine running a su hif44 carb on rock watt manifold, have checked the compression which is spot on, so if anyone has any advice that would be much appreciated.
many thanks adam

Re: White smoke on start up overfueling

Posted: Sun Jan 22, 2017 11:00 pm
by twiss
tried tweaking the mixture?

Re: White smoke on start up overfueling

Posted: Sun Jan 22, 2017 11:11 pm
by evolve123
that was my next thought but wasn't sure whether to or not.

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 1:31 am
by twiss
Yeah give it a go, just jot down how much you move it.
To be honest, white smoke is more likely burning water from a headgasket failure... fuel smoke is normally black

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 9:58 am
by ScottieJ
white smoke and a misfire could also be caused by a failed inlet manifold gasket allowing water into the inlet. do any of the plugs look washed and really clean?

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 8:40 pm
by evolve123
Thanks i'll give the mixture a try and see what happens its defiantly fuel soaking the plugs its not loosing water, the misfire gets worse as it heats up, could the oil in the dashpot on the carb cause this.?

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 8:54 pm
by Jordi
Compression test it. Sounds like a gasket with the misfire.

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 8:55 pm
by ScottieJ
As it heats up metal expands and often increases the size of any leaks etc. This is a typical symptom of an inlet coolant leak. Usually if it's an inlet leak it's such a small amount of water that gets in it's just enough to cause running issues but not enough to notice a loss of water over a short period so don't rule it out. Espiecially if the smoke is thick and white, not blue. Only thing it can be if it's white is water/coolant.

Re: White smoke on start up overfueling

Posted: Mon Jan 23, 2017 9:28 pm
by evolve123
ok thanks ill definitely check it out and have a look for a leak, I've done a compression test and all 4 cylinders were bang on the same, its not thick white smoke just a bit like bonfire smoke lol! but it stinks of fuel.

Re: White smoke on start up overfueling

Posted: Sat Jan 28, 2017 9:23 pm
by evolve123
I've managed to get in the workshop for a few hours last night, tweaked the mixture screw a bit but nothing changed!, I've put all new ignition parts on i.e. coil plugs leads rotor arm, which has cured the misfire, now it smokes less on idle but it pours out under load.
wonder if it just needs starting from scratch, check the timing, valve clearances, and carb rebuild. or convert it to efi.