Jump to content
SAU Community

Recommended Posts

Hi all,


Trying to find a misfire in my freshly rebuilt rb26.


The car misfires from idle to 3000rpm ish (haven't taken it higher)


What I have done to pinpoint the miss is


Unplug each coil pack (the exhaust note changes with each one unpluged)


Unplug each injector (same results as coil packs)


New plugs


New Crank angle sensor


Compression test showed all 6 cylinders even (148psi)


Sprayed carby cleaner around the place looking for vacuum leaks


Injectors have just been professionally cleaned


Unplugged the air flow meters. Car seems to idle smoother but misfires the same once I build revs up a little.


Not sure where to go from here?


Advice appreciated!!


Link to comment
https://www.sau.com.au/forums/topic/456886-freshly-built-rb26-misfire/
Share on other sites

You should try changing the coils. Just as a process of illumination. Check injector plus make sure thats fine with a node light. Should be one of those. Last resort could be a broken ring. Need to do a leak down test. Wit broken ring its tricky. I had one years upon years ago but had compression.

Cheers for the replies.

I should mention the issue started after it was assembled then went away. It had it's time on the dyno and has started playing up again.
The motor probably has about 50kms on it.

The Valve seats where cut. I'm using Tomei Type B springs.

Timing is spot on.

Going to try igniter and coils packs from a mate.

Cheers

What I don't understand is why I can't pinpoint the missing cylinder via unplugging the coil packs 1 by 1.

cause of its valve springs it will be all cylinders

There was a thread only a month or so back where he had a missfire issue on a built engine and it turn out to be springs, also have seen it on about 3 other cars

  • 2 weeks later...

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

    • Who did you have do the installation? I actually know someone who is VERY familiar with the AVS gear. The main point of contact though would be your installer.   Where are you based in NZ?
    • Look, realistically, those are some fairly chunky connectors and wires so it is a reasonably fair bet that that loom was involved in the redirection of the fuel pump and/or ECU/ignition power for the immobiliser. It's also fair to be that the new immobiliser is essentially the same thing as the old one, and so it probably needs the same stuff done to make it do what it has to do. Given that you are talking about a car that no-one else here is familiar with (I mean your exact car) and an alarm that I've never heard of before and so probably not many others are familiar with, and that some wire monkey has been messing with it out of our sight, it seems reasonable that the wire monkey should be fixing this.
    • Wheel alignment immediately. Not "when I get around to it". And further to what Duncan said - you cannot just put camber arms on and shorten them. You will introduce bump steer far in excess of what the car had with stock arms. You need adjustable tension arms and they need to be shortened also. The simplest approach is to shorten them the same % as the stock ones. This will not be correct or optimal, but it will be better than any other guess. The correct way to set the lengths of both arms is to use a properly built/set up bump steer gauge and trial and error the adjustments until you hit the camber you need and want and have minimum bump steer in the range of motion that the wheel is expected to travel. And what Duncan said about toe is also very true. And you cannot change the camber arm without also affecting toe. So when you have adjustable arms on the back of a Skyline, the car either needs to go to a talented wheel aligner (not your local tyre shop dropout), or you need to be able to do this stuff yourself at home. Guess which approach I have taken? I have built my own gear for camber, toe and bump steer measurement and I do all this on the flattest bit of concrete I have, with some shims under the tyres on one side to level the car.
    • Thought I would get some advice from others on this situation.    Relevant info: R33 GTS25t Link G4x ECU Walbro 255LPH w/ OEM FP Relay (No relay mod) Scenario: I accidentally messed up my old AVS S5 (rev.1) at the start of the year and the cars been immobilised. Also the siren BBU has completely failed; so I decided to upgrade it.  I got a newer AVS S5 (rev.2?) installed on Friday. The guy removed the old one and its immobilisers. Tried to start it; the car cranks but doesnt start.  The new one was installed and all the alarm functions seem to be working as they should; still wouldn't start Went to bed; got up on Friday morning and decided to have a look into the no start problem. Found the car completely dead.  Charged the battery; plugged it back in and found the brake lights were stuck on.  Unplugging the brake pedal switch the lights turn off. Plug it back in and theyre stuck on again. I tested the switch (continuity test and resistance); all looks good (0-1kohm).  On talking to AVS; found its because of the rubber stopper on the brake pedal; sure enough the middle of it is missing so have ordered a new one. One of those wear items; which was confusing what was going on However when I try unplugging the STOP Light fuses (under the dash and under the hood) the brake light still stays on. Should those fuses not cut the brake light circuit?  I then checked the ECU; FP Speed Error.  Testing the pump again; I can hear the relay clicking every time I switch it to ON. I unplugged the pump and put the multimeter across the plug. No continuity; im seeing 0.6V (ECU signal?) and when it switches the relay I think its like 20mA or 200mA). Not seeing 12.4V / 7-9A. As far as I know; the Fuel Pump was wired through one of the immobiliser relays on the old alarm.  He pulled some thick gauged harness out with the old alarm wiring; which looks to me like it was to bridge connections into the immobilisers? Before it got immobilised it was running just fine.  Im at a loss to why the FP is getting no voltage; I thought maybe the FP was faulty (even though I havent even done 50km on the new pump) but no voltage at the harness plug.  Questions: Could it be he didnt reconnect the fuel pump when testing it after the old alarm removal (before installing the new alarm)?  Is this a case of bridging to the brake lights instead of the fuel pump circuit? It's a bit beyond me as I dont do a lot with electrical; so have tried my best to diagnose what I think seems to make sense.  Seeking advice if theres for sure an issue with the alarm install to get him back here; or if I do infact, need an auto electrician to diagnose it. 
    • Then, shorten them by 1cm, drop the car back down and have a visual look (or even better, use a spirit level across the wheel to see if you have less camber than before. You still want something like 1.5 for road use. Alternatively, if you have adjustable rear ride height (I assume you do if you have extreme camber wear), raise the suspension back to standard height until you can get it all aligned properly. Finally, keep in mind that wear on the inside of the tyre can be for incorrect toe, not just camber
×
×
  • Create New...