Rb20Det Missing Randomly?

[tobs_r32]

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!!

[toffy]

odd , black smoke coming out of the exhaust?? , check your cooler pipes and the rest of your fuel lines?

[pipster11]

could be the afm pins coming loose

http://www.skylinesaustralia.com/forums/topic/113284-fixing-your-rb26-afms/

[tobs_r32]

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.

[tobs_r32]

THinking coil packs, just took it for a decent drive down past hounville ran fine the whole way not a hiccup still got shitloads of power so it must be a random drop out occuring or a f**ked sensor??

[DanielH]

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.

[tobs_r32]

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

[Funz]

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

hit me up with a text

Edited July 15, 2011 by Funz

[DanielH]

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.

[tobs_r32]

Alrighty, thanks heaps for all the help guys and funzy i will do mate, and yeah runnning .8 gap on the plugs! cheers!! hopefully i'll have it going again next week then

[Dave.TAS]

Toba I have a brand new coilpack loom here for your motor which might help your issue, and regardless is usually good to replace

[tobs_r32]

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?

[toffy]

Possibly

[XRATED]

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.

[tobs_r32]

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?

[grandmasterb]

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

[pipster11]

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