Jump to content
SAU Community

Missfiring after a auto to manual conversion

elohim_imanu
 Share

Recommended Posts

elohim_imanu Contributor

elohim_imanu

Posted
Posted

So every since the conversion if have a miss-fire. It seems to happen in the rev range of 1100-2500.

The car was sitting for a few months during the conversion.

1. Changed the plugs

2. Coil packs are brand new

3. Unplugged coils one by one, they all display similar behaviour  

4. Sprayed all over vacuum hoses etc with brake cleaner, can't hear anything change

5. Vacuum tested when running, looks normal.

6. Unplugged the O2 sensor, no change. ecutalk is seeing voltage. 

7. Swapped CAS with another good one

8. Resistance check the coil loom

9. The battery was disconnected for weeks during the conversion, so the ECU has been reset.

I have a consult (ecutalk), but I don't really know what to look for, other than error codes, which there are none.

I am running out of ideas.

PS It is a N/A

IM-32-FK Mentor

IM-32-FK

Posted
Posted

Usually with all the skylines I’ve owned issues at 2500rpm always seemed to be related to the air flow meter. Usually when the AFM is dead it limits your revs to 2500. Your one might be dirty as f**k inside it, or you may be even using the wrong one. So clean it with contact cleaner or afm cleaner. Just make sure one side of the afm has the mesh on it though, because removing that also causes problems. Also check the afm wiring, it might be loose or come off.

I would also clean the inside of the boost solenoid. 

elohim_imanu Contributor

elohim_imanu

Posted
  • Author
Posted

Thanks. I will clean it and check the wiring. But I have not changed it during the conversion. I think it is OG. I wish I had a boost solenoid. NA.

It does rev right out. It is just missing a bit and feels like a vibration in the lower revs.

elohim_imanu Contributor

elohim_imanu

Posted
  • Author
Posted

Cleaned the AFM and throttle body.

Still no change.

I am starting to wonder if the flywheel or pressure plate is out of balance and what I am feeling is a vibration.  It does increase with revs and there is a small vibration on the clutch pedal in the high revs. 

  • 2 years 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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • AdiR34
      Pops when backing off throttle, rough-ish sound through rev range.

      By AdiR34 · Posted

      Yes to both! Yes to standard ECU and tune, but exhaust is aftermarket. Unsure on brand. Actually have it sitting in at my desk haha! I have to set it up on my laptop but this is a great next step, will do. So I generally try to shift before 4.5K RPM most times. I largely don't do a lot of high-rev driving, but I will take it up to red 1-2x a week max, as I know the occasional "Italian tune-up" is good for these cars.  Oh wow, is this way better than what I'm getting. Does this mean there's a good chance I have an issue?   Thanks for all the info so far guys.
    • Roy
      Ben's R32 Gtst Build

      By Roy · Posted

      Old Son, did you re-use the Holden ABS in the new shell or try a different module?
    • GTSBoy
      Another little story of weird shit happening

      By GTSBoy · Posted

      Yeah, nah. I had the actuator rod off it today. The arm will not move at all. Neither out, nor in. Yeah, you'd think so, but I've been thinking about that. Even when the actuator rod fell all the way off at the beginning of this saga, it would build more boost and faster in lower gears than it would in higher gears, and you'd think that that was the opposite of what should happen. But I strongly suspect that there is a thing with the gearing getting the revs to rise faster, that there must be some transient effect with the gas flow rate rising quickly, that you don't get with the more steady state case of the higher gears. Keep in mind - the gate is not shut in either of my weirdnesses. So things are not "normal". We normally think about a turbo spooling up (below the wastegate target) with the gate shut. I have all sorts of mental models running now where the gate is a little bit open, and having it stuck open allowing gas out while it should be going through the turbine has all sorts of weird effects (in these mental models). I'm thinking in the higher gears, the ex mani pressure builds to the point where enough gases spill out the wastegate to just prevent the pressure rising much more at all, or just creeping up, all the whole the revs are increasing and getting closer to the point where a gear shift becomes necessary.
    • MBS206
      Another little story of weird shit happening

      By MBS206 · Posted

      Is it possibly wastegate actuator itself is sticking, or even the rod to flapper? Otherwise I reckon things are getting a bit rusty/worn   Also odd it won't boost in 3rd to 5th, but will in 1st, I'd expect the other way around with it slightly open as there's more time on your way to redline for it to spin up
    • Shizu
      Returning after a long time!

      By Shizu · Posted

      Does anyone know ow what these two plugs are for and if they should be unplugged? Just put the dash back together and can't remember if these were plugged in before or unplugged! (Blue and white plugs) 🤦🏽‍♂️
×
×
  • Create New...