Jump to content
SAU Community

Recommended Posts

how a fuel injector ruined my life.

some of you may not know but i couldnt go to the trackday :rant: reasons being my motor crapped itsself finaly. well after 240000km of reliable service.

it started off as a missfire when it was cold in the mornings, just a light one. having a wideband afr meter made this easy to see that it was to lean on cold start up. easy fix, with the autronic i increased the cold start fuel multiplier. fixed :O

after 2 weeks it did it again :S so i re tuned the low rpm fuel sites for more fuel. that fixed it.

then.. the battery went flat, it some how lost its tune after sitting for a week. very strange.. so i retuned. fixed.

and after another two weeks it progressivly got worse and worse till it was missing under boost then just light throttle., so i did the logical thing and put a new set of plugs,and leads into it. that didnt help. ok..

so.. i thought it may may be the cdi unit playing up. i have a spare as one crapped its self earlier due to rain in it lol. it was a fixed one so in ti went. that made no differance. so i put some new coils in.

(the whole time chasing a spark issue.miss under laod while afr is ok)

the new coils made a slight differance. but still not fixed. i checked the wiring from it to the coils. turnes out the wiring was no good. so i made a new harness from the cdi to the coils. no change... f**k!!!

hrmm well i used my old bosses occiloscope to check the outputs on the ecu for the injectors and the cdi unit. they were ok. but being a lcd sreen scope the reponce was not quick enough to garentee a clean signal.

so for the hell of it i changed the crank angle sensor(i had to pull it apart and put a autronic chopper disc in it) that made no differance. gay!!

so out comes the compression testor. yay 5 was down. then 6, then 4, then 3. whoa my motor was dieing quick! ok so i used another comp tester. wtf it was all 140psi hrmmmm.. dodgy comp testor.

still missfirng, comp good. afr good, spark good. mayby its the ecu?? but not an autronic! mayby it was a broken valvespring. i recently put cams in.. so mayby the higher lift fatiged the old springs. oh well after a sold 10 hours changing the head over iin car. (not easy on a gtr) it still missed!!!! grrrrrrrr.

ok must be a broken ring land(s) cos they can give good compression and then not good as the ringland mioves around. oh well il just put my built motor in then.

soo on the weekend i swapped over my engines. pitty our work doesnt have a engine crane jjust a forklift and a big steel tabe. so it was out with the motor/box as one unit onm the crossmember.

anyway i got it done and wtf still missing. but now at idle. f**king hell. cos itr was at idle i could norrow it down to no.4 f**k waht is it.. i swapped my injectors around (there only a year old) and the problem moved. coool spo its a lasy injector.. i pulled the filter out of it and cleaned it. yay no more missfire!! woot and i have a new motor ready for 2 bar eheh

moral of this is never asume something is ok. ie..my new injectors and if its intimitant be prepard for what ive gone thru unless you put it on a dyno. it would of saved me a months stress for the sake a 1 hour on the rollers eek. :rant:

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/
Share on other sites

Bad luck man, like life you live and learn shit happens at least your mechanically minded, as soon as my car seems a miss or not running correctly i get my mechanic or tuner to ckeck it out. Now you have a built motor ready for 2bar boost yeeeeh haaa..

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/#findComment-3219967
Share on other sites

lol great story so many twists and turns....on the bright side you worked in out before you lunched the new motor as well.....

I've put a whole heap of std gtr injectors through flow testing and cleaning - and they all flow horribly....rated at 440cc/min none of them, even r34 freshly cleaned ones pumped more than 400cc/min (except a freak set of 4 from a gtir that did 450, maybe they had been highflowed).

I had a similarly frustrating issue that turned out to be dodgy fuel pump wiring, almost cost me a brand new motor because every time we tried to run it in it ran like crap (missing) causing fuel wash one the bores....very frustrating I swapped bloody everything (wish we had a fuel pressure gauge)

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/#findComment-3220465
Share on other sites

To4GTR,

lol quite an adventure. :S

Duncan,

400cc's was at 100% duty or Pulsed duty (80%)

I had a set of apparent low km R34 GTR injectors flowed and cleaned some time ago.

Before cleaning they were fine; after they were only slightly better.

Averaged 472cc @ 40psi (min 468 max 474)

After cleaning

Averaged 476cc @ 40psi (min 474 max 480

Pulsed duty (80%) they flowed 384cc to 390cc

post-382-1183972337_thumb.jpg

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/#findComment-3220569
Share on other sites

Sorry to hear Dave but the good thing is that your misfortune might lead to me fixing my problem.

At the moment my car is missing under boost.

Dont know too much about cars but i was thinking maybe air flow meter or fuel pump or something in the fuel filter blocking it, sparks, coils... never though to check injectors...

Ill change them and keep ya informed. Thanks again.

Soul.

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/#findComment-3221238
Share on other sites

I had a similarly frustrating issue that turned out to be dodgy fuel pump wiring, almost cost me a brand new motor because every time we tried to run it in it ran like crap (missing) causing fuel wash one the bores....very frustrating I swapped bloody everything (wish we had a fuel pressure gauge)

good story Dave! I wish I was able to sort problems like this my self!

And Duncan I hear you on the wiring issue :rolleyes: its the reason I missed the track day

Link to comment
https://www.sau.com.au/forums/topic/175822-my-weekend/#findComment-3221273
Share on other sites

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

    • I'd say the easiest way is, pick up a extended and baffled sump with fittings already welded on. Here is an example, it has 3 x -10 fittings  https://shop.maatouksracing.com.au/products/rb-extended-and-baffled-sump
    • hey OP can you remind me what the actual question was, I got sidetracked at V12. Do you have an turbo oil return leak and an unidentified coolant leak? The factory oil returns are terrible design; short, rubber and expensive to replace. They are very common to fail and a pain to replace because they are so short. Still, they are available new if you want to replace both last time I checked. For the coolant leak, any competent mechanic should be able to do a pressure test; that should show up where the leak is. It is almost certainly one of the billion 30 year old rubber lines which are now brittle as hell, you engine will be fine.
    • From the OP's description, sounds to me like the TCU is in 'limp home' mode --- that is, no actuation power to shift solenoids, and the EPC valve is shut (full line pressure). This effectively sticks the box in 3rd gear, with as much line pressure as possible, to try hold the high clutch clamped shut....and so you get woeful acceleration and don't feel any shifts (because they're not happening). If you don't have Consult or some other scanner to interrogate the TCU itself, you can test with a multimeter to see if it's in limp home mode....ie; stick it in D with engine at idle (hold vehicle with hand/foot brake), and measure the voltage at the TCU feeding shift solenoids A & B -- both should be ON (battery voltage). If they are energized at the TCU, you can unplug the harness from the TCU, and check resistance down through the wiring to the solenoids themselves -- you should see about 20ohms on each coil --- if you do, you can presume the wiring to shift solenoids is OK -- if both measure open circuit, you have to check intermediate connectors in the loom down to the gearbox (and the gearbox connector itself), and check the shift solenoid resistance at the gearbox connector itself --- if the shift solenoids test open circuit here, problem is in the box (ether the solenoids or wiring to them is bad). If you get no voltage at TCU connector for the shift solenoids (and the solenoids/wiring test OK), check powers/grounds to the TCU itself --- if they're ok, it suggests the TCU is the culprit (and you'd need to interrogate it if possible, to find out why it's behaving badly)... 
    • Hey mate give Autotechnica a go, I recently got some Comfort PUs and rails from them, they're comfy and look great highly recommended! https://www.autotecnica.com.au/part-finder/nissan/skyline/r32/
    • Honestly, for a daily I would gladly rock a Camry. The more disposable the better. People drive horribly out here and road conditions are awful.
×
×
  • Create New...