Jump to content
SAU Community

Mystery Problem With Injectors+spark

RB20_ZED

By RB20_ZED,
in Engines & Forced Induction

 Share

Recommended Posts

RB20_ZED Collaborator

RB20_ZED

Posted
Posted

A few days ago i took off from a set of lights pretty hard, spun the wheels a bit and all of a sudden the car spluttered, hesitated and nearly stalled when i took it out of gear.... but i got it home and took it to the mechanic who did some tests and said its running super rich and missing etc.

He looked around and eventually called me and said it was the cold air idle valve (he unplugged it and suddenly the car ran perfect)... which made sense coz its been running badly when cold for a long time.

When i came to have a look, he tried to start the car and it wouldnt start at all... so he kept it and said that there was no spark and no power to the injectors...

So we get the ignitor and CAS checked and they are both working fine... and after putting them both back on he now said that there is "a little bit of power" going to the spark plugs and said he is going to pull them out and have a look...

im starting to get the shits with the way things are going and wanna know if anyone has any ideas or suggestions as to what the prob may be???

(Its an RB20det)

Link to comment
https://www.sau.com.au/forums/topic/160067-mystery-problem-with-injectorsspark/
Share on other sites
RB20_ZED Collaborator

RB20_ZED

Posted
  • Author
Posted

Thanks for your help guys.

could be spark plug gap . that can cause misfire = also check your coil packs arent cracked . you loose spark through cracks

Nah mate - its running super rich which fouled the spark plugs... cleaned them and its definately getting spark (and power to the injectors) - i think the mechanic was stupid/didnt know what he was checking.

AFM not plugged in properly, or just simply shagged?

Yeh i thought that but ive checked it and cleaned it with electronic cleaner and still the same - and all the little wires seem intact with the afm... guess it could be screwed- how could i diagnoise a faulty AFM besides swapping it?

Could a faulty O2 sensor cause this kind of rediculous over-fueling? ive been reading a ton of posts and hearing a lot about ecu's in limp mode but cant seem to find an explanation of what that means...???

its so rich that its un-driveable... idles irratically at around 400 or so and the engine stalls very easily... revvs like a pig and blows plenty of smoke... way too rich. Any more suggestions would be very much appreciated.

cheez Mentor

cheez

Posted
Posted

sounds like the same issue that i had some time ago.

check your afm properly, it may look like the contacts are ok but skyline standard afm's have a case or getting dry solder cracks.

check out this post for the simple fix, its just a matter of adding more solder, if it dun work well at least you know ur afm wont falter any more under heat with new solder in play.

hope it helps

http://www.skylinesaustralia.com/forums/in...p;hl=afm+repair

daniel

RB20_ZED Collaborator

RB20_ZED

Posted
  • Author
Posted

thanks heaps for your help guys.

WazR32GTSt:

I checked the intercooler piping and took the joints apart and connected them all real tight and no change.

The injectors do work - the mechanic was just dumb - the sparkies just get fouled real quick. Had to clean the black off the spark plugs again today so that it would at least start.

cheez:

I can get it to rev over 3000rpm so does that rule out the afm issue? it doesnt rev nicely... but i can still get it over 3000 (smokes out the neighbourhood tho!)

Im starting to think its the ECU...

cheez Mentor

cheez

Posted
Posted (edited)

doesnt rule it out actually rules it IN!

if the afm doesnt get a clear signal, it send the car into wats called limp mode where it doesnt allow the car to rev above 2500-3000rpm. try the dry cracking solder repair and it should fix ur prob by the sounds of it.

the smoking issue is also part ot the problem, the afm doesnt have any idea of air going into the engine so either over compensates or runs lean. try it. only takes about 30mins to do.

hope it helps

Edited by cheez
RB20_ZED Collaborator

RB20_ZED

Posted
  • Author
Posted

Update:

Took the AFM off and did the re-solder job as well as cleaning it out with electronic cleaner again.

To be honest the solder looked fine but still thought id do it...

There was no change. Car still runs super rich and is undriveable. Maybe the AFM circuitry is fried but cant get hold of another to test this theory (its the red top AFM - different to the silvertop)...

Thanks for your help again guys... and if anyone else has any suggestions (or knows where i can buy a AFM for a red top rb20) - lemme know!

I spose theres a chance the AFM is fine and ECU mite be fried instead...?

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

    • niZmO_Man
      Borg Warner EFR Series Turbo's V 2.0

      By niZmO_Man · Posted

      Not that I know from experience, but in theory you'd want your gate spring to be as close to target pressure as possible, so you'd go with the higher gate spring?
    • Borci88
      Borg Warner EFR Series Turbo's V 2.0

      By Borci88 · Posted

      Before I commit to it as I already have the wastegate off the car, would you change it to the 9psi spring instead of the 12, or whack it back on now and try your suggestion?   Edit: Actually I might just swap the spring and see what the logs say after another few pulls, as we know it's still spiking without the Mac valve in the picture so I need more data without the Mac valve trying to combat the issue.
    • Murray_Calavera
      Steps to DIY sanding car back ready for respray....

      By Murray_Calavera · Posted

      Sounds good Hmm suppose the main thing is, how much do you care about this car? The filler doesn't make for a very good water barrier lol. If there was a tiny little bit of rust forming now, that in 3 to 5 years time becomes obvious under the paint (starts to bubble up), would it bother you? 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I already have the ability to datalog the voltage... what I can't do is correlate it to what the gauge is showing when I'm looking at the data at a later date. Or something like this. Except getting the oil to 125C+ involves me going 200+kmh at the track so you can imagine this is a little tricky unless I do something like note what the voltage is when I am at the top of 5th gear so I have a point to reference on. Drove car today. O2 still reading richer because hopefully not a leak instead of massive restriction I've introduced. Car really doesn't sound like a LS. It's quite strange. Pulled a bit of fuel out up top. This does potentially explain why my spark plugs looked like the car was running pretty over-rich. If I was tuning it to a ~12.7 which in reality was far richer than that in the past. It will be handy to have the dyno WB to compare my WB to to compare notes that's for sure. At this point I'm happy to just sit in the passenger seat and tune the thing given I've got about 7 million hours on the platform lol.
    • Chocolate Cheesecake.
      Infiniti Q60 Navigation Update

      By Chocolate Cheesecake. · Posted

      Yeah I understand you have to pay for an updated map or subscription service or something. But I can't even find a current map for Australia. My map is dated 2017, but didn't this car version still sell in Australia until 2021?   Also, just as an aside, the navigation system warns you of traffic incidences ahead.....why would they include that on a map they knew is not receiving live information. I am forever going to be warned of an incident that probably existed for 30 minutes 8 years ago.
×
×
  • Create New...