Jump to content
SAU Community

Recommended Posts

hey guys...

i'm hoping someone on here might be able to help me...

i've done a search, but i cant find a thread with my problems...

its an RB20DET with fmic, 3" exhaust, fuel pump, t04e (brand new), splitfire coilpacks and irdium spark plugs... STANDARD ECU

basically, when i do a cold start it PISSES out white smoke (smells of fuel not oil) and it misfires on idle... but if you rev the car, the misfiring goes away but there is still craploads of white smoke coming out the exhaust...

but then as soon as you take it for a drive and the engine temp comes up to 'normal', all the smoke clears away (apart from a bit of black smoke cause its running excessively rich) and the misfiring stops on idle...

now.. i'm completely stumped as to why this would be happening... does anyone have any suggestions on what it could be?

i cant see it being a blown head gasket because a) the smoke clears up once the temp comes up to normal, b) the water in the radiator doesnt have a flim of oil on it and c) the oil isnt milky....

i believe i have two seperate problems... but they could be related, i dont know...

the first problem is that its running REALLY rich and i believe thats why the smoke smells of fuel and possibly why its misfiring because the spark plug is getting wet from too much fuel... sometimes it sounds like it running on 4cyl and other times it sounds like its running on 5cyl...

then the second problem is the white smoke which i have no clue on...

PLEASE HELP!!! i cant go on like this... :P

if you need to ask any clarification questions, then go ahead... ;)

thanks

ash

Link to comment
https://www.sau.com.au/forums/topic/173061-misfiring-and-white-smoke/
Share on other sites

Still can be a head gasket :P

You may have a minor crack that leaks into the bore, when cold, then as the engine heats up everything expands and seals up, till it gets cold again. If a gasket leaks water into a bore, the water will never mix with the oil, or vis-versa, and the water will then pass through the exhaust system.

All cars have white smoke in the mornings, but it really depends on how much you consider alot.

I am by no means stating that you have a blown head gasket, just advising that it is still a possibility and should not be ruled out because of the things you have listed.

Easy, White smoke on cold mornings here in brissy at the moment condensation, missfire due to running either colder plugs say 7's as they take a while to come to temp or the excessively always running rich fouling your plugs

Done :P

There is a sensor for cold starts it might be stuffed

Have u ran the diagnotic on the ecu it might tell u what is wrong

good point, thats one thing we havent checked... didnt think it would cause all the smoke... :whistling:

Still can be a head gasket :yes:

You may have a minor crack that leaks into the bore, when cold, then as the engine heats up everything expands and seals up, till it gets cold again. If a gasket leaks water into a bore, the water will never mix with the oil, or vis-versa, and the water will then pass through the exhaust system.

All cars have white smoke in the mornings, but it really depends on how much you consider alot.

I am by no means stating that you have a blown head gasket, just advising that it is still a possibility and should not be ruled out because of the things you have listed.

i was told this by someone else today as well... i had never heard of this happening before... i didnt know the HG could have a 'minor crack'... i just thought that once they go, thats it, its gone!!

i call it "A LOT" when you sit in the car and you cant see behind you because of all the smoke...

Easy, White smoke on cold mornings here in brissy at the moment condensation, missfire due to running either colder plugs say 7's as they take a while to come to temp or the excessively always running rich fouling your plugs

Done :)

when i say "cold start", i dont mean just in the morning... it could be at 2pm in the afternoon... i just mean that it hasnt been started in quite a few hours so the engine is "cold"...

and its not condenstation in the exhaust system... my euro 'smokes' in the morning as well which is caused by condensation in the exhaust system... this is thick white smoke that bellows out of the exhaust pipe...

after all this, it was started today and driven back to my house from my mates workshop and there wasnt a puff of smoke at all and absolutely no mis-firing... so it seems like one day it will smoke and misfire, then the next day it will be fine, then the day after that it'll have problems again... :P

could a minor crack in the head gasket 'come and go' like that?

and would a minor crack in the head gasket cause it to misfire randomly at idle?

i'll start her up in the morning tomorrow and see if she smokes and misfires or not... :)

thanks for the suggestions guys... please keep them coming.. its greatly appreciated! :)

well, the smoke and misfiring is back today...

it kinda sounds like its choking on something on low revs, until you stab the throttle and bring the revs up then it clears up until the revs drop again... :?

any ideas from peoples??? :whistling:

it sounds like you might have a leaky injector hence the running really rich, i cant say i have seen white smoke from fuel but it may be possible that the plugs are not burning it all and is getting onto your turbo and doing something odd with the seals, i had this problem with a silvia a few years ago.

easiest way is to remove spark plugs, unplug ignitor pack, then prime the fuel pump, if you can see fuel in any of the cylinders you have a leak. now it could be either the injector itself or is could be one of the o-ring's that seals then into the fuel rail.

How about valve stem oil seals??

is there anyway of testing that without pulling the engine apart?

i havent had a chance to start the car since my last post... been too busy with work... :O

i'll update on saturday when i take it for a drive... :)

I actually started to think the same thing, but didn't come across this thread again till now.

okay...

any idea on how to check them?

or is it a job for the mechanics to pull the engine apart?

edit: just thinking about it again... would the valve stem oil seal cause BLUE smoke??

i dont have any blue smoke.. its only white... ;)

Edited by S13 SecaBoy

my issue is this...

IF it was using water, then straight away i'd point at the BHG... but its not using any water... :cheers:

IF the smoke was blue, then it'd point to an oil related issue... but the smoke is not blue and its not using any oil...

i'm gonna pull out the spark plugs and see if there is any fuel going into the cylinder with the car off...

firstly though, i'll check to see which cylinder is dropping out... that way i dont have to take ALLLL the spark plugs out... :D

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • OK, Step 3, if you need to remove the valve body, either to replace it, the TCM, or to do a more complete drain.  First, you need to disconnect the TCM input wires, they are about half way up the transmission on the drivers side. One plug and the wires are out of the way, but there is also a spring clip that stops the socket from sliding back into the transmission. On my car the spring clip was easy to get, but the socket was really stuck in the o-ring of the transmission housing and took some.....persuasion. You can see both the plug to remove (first) and the spring clip (second) in this pic Incidentally, right next to the plug, you can see where the casting has allowance for a dispstick/filler which Nissan decided not to provide. there is a cap held on with a 6mm head bolt that you can remove to overfill it (AMS recommend a 1.5l overfill). Final step before the big mess, remove the speed sensor that is clipped to the valve body at the rear of the box.  Then removal of the Valve Body. For this the USDM Q50 workshop manual has a critical diagram: There are a billion bolts visible. Almost all of them do not need to be removed, just the 14 shown on the diagram. Even so, I both removed one extra, and didn't check which length bolt came from which location (more on that later....). Again it is worth undoing the 4 corners first, but leaving them a couple of turns in to hold the unit up....gravity is not your friend here and trans oil will be going everywhere. Once the corners are loose but still in remove all the other 10 bolts, then hold the valve body up with 1 hand while removing the final 4. Then, everything just comes free easily, or like in my case you start swearing because that plug is stuck in the casing. Done, the valve body and TCM are out
    • OK, so if you are either going for the bigger fluid change or are changing the valve body which includes the Transmission Control Module (TCM), first you should have both a new gasket 31397-1XJ0A and a torque wrench that can work down to 8Nm (very low, probably a 1/4 drive one). You can probably get by without either, but I really didn't want to pull it all apart together due to a leak. First, you now need that big oil pan. The transmission pan is 450 long x 350 wide, and it will probably leak on all sides, so get ready for a mess. There are 24x 6mm headed bolts holding the pan on. I undid the 2 rear corners, then screwed those bolts back in a couple of turns to let the pan go low at that end, then removed all the middle bolts on each side. Then, undo the front corner bolts slowly while holding the pan up, and 80% of the fluid will head out the rear. From there, remove the remaining bolts and the pan is off. You can see it is still dripping oil absolutely everywhere...it dripped all night.... I got another couple of litres when I removed the pan, and then another few when I removed the valve body - all up another 4l on top of the 3 already dropped in step 1.
    • Yeh I think i'll message an old contact i had for ages that manages his own tyre shop now.. n tell him what i want n work with him before ordering..  Got this 17x9 +30 Driftteks on 245/45/17 PSR Drag Radials on the rear.. They fit well - for your reference in future - Rear guards  have been lipped in & minimal to non flaring of the rear Gaurds.    
    • If only it were that easy! I also needed to remove seats, shocks, brake calipers, send my car through a fence, and use measuring and ended up guessing because I didn't remove seats, shocks and brake calipers. It can be hard sometimes Can be a little more complex than 'just measure' if you want to truly measure the entire wheel through all of it's suspension travel. But if you aren't going for every last mm then yeah, you can check the space you currently have and guesstimate.
    • If you own a car, and it has wheels on it, and you know the offset of those wheels, and you have a measuring device, you have everything you need to work out if other wheels will fit.
×
×
  • Create New...