Jump to content
SAU Community

Recommended Posts

Gday,after some help with my skyline again :( i was driving my 32 gts-t today after just collecting it from the mechanics and it seemed it was starving for fuel after half hour of driving and began missing and running on 4 cylinders or so. I put $30 fuel in it, revved it out once or twice, drove it out and it was running perfect again halfway down the street. trip to work and back and sandy bay-work and back and got it home and pulled up and it started missing again, drove to the fuel station filled it entirely with fuel and drove it back home and it was still doing it, ran for about 15 minutes and checked over everything briefly and it is still missing, has lost atleast 50% power! Does anyone know what might be causing it?? Service was completed around 200k's ago (Oil, Filter, Plugs) Bosch 040 installed 3 months ago, including fuel filter and some frayed fuel line replaced, and only just had water pump and timing belt etc done. motor has done around 70,000ks

Cheers any help would be awesome!!

Link to comment
https://www.sau.com.au/forums/topic/370994-rb20det-missing-randomly/
Share on other sites

Yeah i tried wiggling the AFM around its just strange because it will run fine now but then just randomly start doing it!! Don't think its blowing any smoke toff and yeah checked the lines, but i didn't know cooler piping would make it miss?? I'll double check all the clamps.

Check all the terminals for the injectors and also the ignitor, CAS and AFM for corrosion on the pins, ive seen them corrode and have intermitten contact issues many times, if they are corroded contact cleaner and/or some emery paper is the bext way to clean it.

The injectors are less likely to corrode, but the terminals in the plugs can stretch/wear out and cause issues, i had an intermittent miss with my supra that drove me mad for weeks and all i had to do was tighten the terminals back up on 1 injector plug.

also check out the coilpack plugs as well.

Will do daniel, cheers heaps mate. I wouldn't be surprised if it was a corroded pin somewhere playing up, so over this car i've had nothing but problems the last month or two straight!! What is the best way to test for a dud coilpack?? Just run while its missing and pull them out one at a time until it doesn't change the RPM and i know thats the dud one?? or is there a better way? Anyone know of any decent coil packs for sale?? Preferably aftermarket

Will do daniel, cheers heaps mate. I wouldn't be surprised if it was a corroded pin somewhere playing up, so over this car i've had nothing but problems the last month or two straight!! What is the best way to test for a dud coilpack?? Just run while its missing and pull them out one at a time until it doesn't change the RPM and i know thats the dud one?? or is there a better way? Anyone know of any decent coil packs for sale?? Preferably aftermarket

hey toby, i got some stock coil packs here if you need them to test

you got .8 gap on your plugs? all the missfires ive had have been plug /afm or coil pack related, afm or piping would explain severe drop in power

or since my cars off the road i can lend you my JJR ones as well to test, run a z32 so cant lend the afm :P

hit me up with a text

Edited by Funz

Yeah if it will idle with the miss just disconnect the coils one by one, thats the easiest way...if you can narrow it down to a particular cylinder then focus on all the connections for that one.

Ah cheers dave but i had a really decent inspection today and they all look to be perfect, all wiring and connectors the coils themselves look like new!! Can't for the life of me get it to do the same thing again!! Has been started randomly a couple times a day and drove it for hours today... What could have caused it?? I'm beginning to think the problem is gone, is there any chance that having a very flat battery could cause this?? The battery was dead and i had to jump start it to drive it the day it started happening?

Ah cheers dave but i had a really decent inspection today and they all look to be perfect, all wiring and connectors the coils themselves look like new!! Can't for the life of me get it to do the same thing again!! Has been started randomly a couple times a day and drove it for hours today... What could have caused it?? I'm beginning to think the problem is gone, is there any chance that having a very flat battery could cause this?? The battery was dead and i had to jump start it to drive it the day it started happening?

Yeah a very dead battery, poor connectors and a poor earth connection can cause similar issues. Another possible cause is the key way in the back of the CAS.. the seem to flog out after a while and the timiing can go 'ALL' over the joint on the move.

I would start with a new battery, with new terminals, new 4ga earth straps (one from batt to chassis, one from the back of the head to chassis), check the CAS and double check the ign.

Also, were both fuel filters changed?

Cheers

J.

Yeah i believe they were, well it's funny you say that because randomly i'll come out to the garage and the alarm wont respond at all, so i open the car with the key and it won't turn over because it has no power!! So after the first time i figured out that jiggling the terminals on the battery makes it come back on, its done this prob 3 or 4 times over the last few months, i've never had an issue with the battery but should i replace that too?? Or just the terminals?

Get your battery checked to see if its charging ok and still in good health.

If its ok:

clean your terminals or replace them (not cheap nasty ones from Repco either)

clean the posts on the battery

make sure you have good earths

from memory there is a plug that goes into the +'ve terminal too, mine was loose on my 32

just use the wiggle method, start the car, wiggle wires and stuff and listen for the motor to change its tune

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

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...