Jump to content
SAU Community

Recommended Posts

hey all, having some dramas with my car and want some opinions, im struggling to narrow down what the issue is.

its running really rough, it seems to be hunting, and possibly burning oil (im yet to suss out the colour of the smoke properly, however it smells like fuel).

Oil and water are the colours and at the levels that they should be, the cooling system is not pressurising straight away and its not steam coming form the exhaust so im fairly confident that its not the head gasket.

the weekend before last i drove out to port augusta and back (surely getting some dirty ass fuel along the way). My car is my daily driver, and when i got in on wed arvo to drive home from work is when it started missing/runnig rough, i was quite low on fuel at this point.

I have swapped out the plugs this arvo, and they were really fouled. put in a set of new plugs and it runs the same (however i did not gap them cos i dont have my feeler gauges at my gf's place). on visual inspection the coilpacks seem ok, but i really have nfi what im looking for to spot a faulty coil pack. in addition the AFM appears clean and ok.

my question is, what can lead to those symptoms of hunting, running rough and being smokey? rings? dirty injectors? dead coil/ignitor pack? dead AFM?

im grateful for any help i can get!

Link to comment
https://www.sau.com.au/forums/topic/372049-missfirerunning-rough-and-hunting/
Share on other sites

  • Replies 47
  • Created
  • Last Reply

Top Posters In This Topic

I had the same issues in my S15 - turned out I had gotten a dirty batch of fuel (from Southern Cross - never again) and it had clogged up the intake sock on the fuel pump 80%, so not enough fuel was getting through. It didn't seem to lean out, but rather hunted and had similar symptoms to yours. Ended up having to replace the fuel pump and remove the fuel tank to have it steam cleaned internally - there was 1cm of gunk/mud in the bottom of my fuel tank! And that was when the car was only about 30,000km old.

my immediate reaction is AFM, but it could well be the dodgey fuel.

then again, I run mine down to vapour basically every time and thats never happened lol.

also, check all the intercooler piping.

if it was coilpacks,

start the car, pull one clip off at a time and the one that DOESNT make a difference is the one thats not working.

if you disconnect a WORKING coilpack it will become worse.

thanks for the input guys,

first up i'll suss out the joiners and cooler piping to try and find obvious flaws... reckon i will replace the lot as they are quite old and some appear a little perished.

failing that i'll play the coil pack game (am i likley to cop 12 volts up my arm pulling the loom from the coils?).

if that tells me nothing i'll pass it on to a mechanic to suss out the fuel system etc, i dont fancy being covered in petrol again.... got enough of that from that ke36 wagon i had

as for the smokey exhaust/fuel smell, a hole of some sort in the intake, faulty afm, or faulty coil pack makes sense.... the hole in the intake or faulty afm means the ecu could think there is more air than there really is going into the car, and would pump in more fuel than necessary which would make its way out the exhaust. coil pack not operating i suppose would have a similar effect.

nah its a gts-t matt. thanks for the offer :)

the piping is fairly ugly & mismatched... could do with a re-vamp. my fmic uses the stck piping positions similar to a cooling pro one. wont get too far ahead of myself tho... will pull it apart and have a good look at it all.

i have not noticed it leaning out, i have been driving like a nanna cos my clutch is about to let go (soon as i hit boost it slips :( ) *****looks at steve for clutch hookups*****

changing the fuel filter only takes a couple of minutes to do, good idea to check if the fueltank/pump sock is clean if you find your filter is clogged.

taking off individual coilpacks as the car is running wont result in a shock, good idea this one to see if its a dodgy coil.

If your coilpacks are breaking down you could try a cheapfix method..... purchase selleys 401 industrial strength hitemp silicone sealant ($15 bunnings) use a corking gun ($2) and lather the coilpacks in the silicone- helps top wasted arc, but only generaly for boost applications (if your coilpacks are one the way out you're better off purchasing a replacement set).

Clean air filter (pod or panel), clean your Air Flow Metre with contact/brake cleaner spray & make sure your contacts are good. There is a DIY-guide on how to fix faulty AFM's in the relevant section, definately worth while to source a spare afm and testdrive to eliminate this potential problem.

Perhaps after this try a compression test; worse case could be glazed cylinder wall. Start with the basics and work your way from there...

Cheers Brendan, thats some good info. l think the fuel filter is a must, if not only beacuse of how long it has been in the car.

after sussing out the cooler piping (im guessing it would be an obvious leak for it to run so rough at idle). i'll attack the AFM

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

    • This is how I last did this when I had a master cylinder fail and introduce air. Bleed before first stage, go oh shit through first stage, bleed at end of first stage, go oh shit through second stage, bleed at end of second stage, go oh shit through third stage, bleed at end of third stage, go oh shit through fourth stage, bleed at lunch, go oh shit through fifth stage, bleed at end of fifth stage, go oh shit through sixth stage....you get the idea. It did come good in the end. My Topdon scan tool can bleed the HY51 and V37, but it doesn't have a consult connector and I don't have an R34 to check that on. I think finding a tool in an Australian workshop other than Nissan that can bleed an R34 will be like rocking horse poo. No way will a generic ODB tool do it.
    • Hmm. Perhaps not the same engineers. The OE Nissan engineers did not forsee a future with spacers pushing the tie rod force application further away from the steering arm and creating that torque. The failures are happening since the advent of those things, and some 30 years after they designed the uprights. So latent casting deficiencies, 30+ yrs of wear and tear, + unexpected usage could quite easily = unforeseen failure. Meanwhile, the engineers who are designing the billet CNC or fabricated uprights are also designing, for the same parts makers, the correction tie rod ends. And they are designing and building these with motorsport (or, at the very least, the meth addled antics of drifters) in mind. So I would hope (in fact, I would expect) that their design work included the offset of that steering force. Doesn't mean that it is not totally valid to ask the question of them, before committing $$.
    • The downside of this is when you try to track the car, as soon as you hit ABS you get introduced to a unbled system. I want to avoid this. I do not want to bleed/flush/jack up the car twice just to bleed the f**kin car.
    • But again, the engineers said your cast aluminium would be fine based on the load that would be stretching that section. Same load stretching the bolts in a flex (not the twist), with a much smaller cross sectional area than the original part you've broken. It's why you'd need to be using higher strength bolts, but that's just making up for the strength you lose with less area...
    • I am truly amazed someone on this planet was able to cycle the pump using a scan tool. I've always ghetto cycled them on Nissan 90s shit boxes by slamming the brakes and pulling the handbrake to agitate the rear wheels enough to cause a speed difference
×
×
  • Create New...