Missfire/running Rough And Hunting

[bezender]

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!

[Matty 31]

if you ran fuel a bit low, maybe look into changing the fuel filter, especially if the fuel was low quality too

[Jap_star]

Still stock fuel pump?

[Import S13]

Check for cooler hose leaking or off somewhere.

If nothing, borrow a working AFM and check that.

[Madaz]

yeah Kyes thoughts were my thoughts too

a small crack on one of the 90deg joiners

[Nightcrawler]

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.

[XKLABA]

excactly same thing happened to my R32, it was the gasket between the throtle bodies and the engine,get a can of brake cleaner and run it around the intake plenium and if the idle changes at all then there is a vacuum/boost leak

[dark.sky]

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.

[Matty Sherlock]

Yeah intercooler piping and Afm. I've just changed mine and the car hasn't missed a beat. I was having the same peoblems as you. Good excuse to throw some polished pipes on haha

[rad100]

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.

[bezender]

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.

[dark.sky]

When my AFM died it was swapping between running super lean and pinging like a bitch, and super rich and fouling plugs.

[Matty Sherlock]

Is your 32 a Gtr mate? I have some oem piping you could borrow to get you by if you want. Only one of them was cracked when I replaced them..

[bezender]

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*****

[Madaz]

Too easy Carl do you want a 350rwkw ceramic or a 300rwkw organic

[bezender]

im thinking organic Steve. I'll PM you later

[Tangles]

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...

[bezender]

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

[Absent]

I had a similiar problem in my 32 it would hunt constantly, sound rough and not want to rev.

it turned out to be a faulty cas, add that to the list

[bezender]

Haha ok, cheers abe... Its on the list