Jump to content
SAU Community

Recommended Posts

So I'm in the middle of my rb25 into a Cefiro conversion and long story short the bloke before me had a Rb25 already in the car but it blew up. I bought the car put new Rb25 in, the car started, timing belt broke killed a piston and head fixed the engine ready to go again and now it wont fire? Car has good compression.

The car cranks fine, it has twin 044 fuel pumps and there both coming on, made sure fuel lines weren't on backwards coil packs have loads of power. It definitely is a fuel problem. Injectors have constant power when I earth them out they click. Put a noid light in and nothing. If I turn the CAS by hand they click and so does the coil packs but the weird thing is if I turn the CAS really slow the noid light comes on but fast it doesn't do anything and when cranking doesn't do anything? When I do turn it slow the light flashes I wait a second and can hear something click under the plenum (only thing under there is the aacv and the weird solenoid thing) then turn it again It flashes again If I don't wait for the click it wont flash...

I've swapped the injectors out for another set I've swapped the CAS out I've tried another injector loom, the only time the car has started is when I swapped the injectors the excess fuel in the rail seeped into the bores and the car started until it ran out of fuel.

I don't think its a f**ked ECU as the car did start before and it did try and start today, problem is I cant see any L.E.D light on the bottom that people talk about and I cant enter diagnostic mode as its a conversion the Cefiro's don't have the plug that your supposed to bridge to enter it... It is a single light rb25 ecu but it doesn't light up? Pulled the cover off cant see anything burnt in there cant see why it would be cooked as nothing has been shorted out.

The only things that are different from the first time is that I put a FFP on and haven't extended the purple plug on the aacv yet as I thought it was useless? I had to extend the AFM wiring so I could put it in the intercooler piping not the turbo intake (as apparently this is better) and the aacv air in pipe isn't hooked up yet (Australia post let me down didn't get my silicone on time) but all of these things should still let the car fire right? It'll just run like balls...

I don't know where else to look now, I'm pretty sure its not a broken wire as it would be pretty unlikely to break every single injector earth wire, the only other thing is pin43 (start signal wire) has been cut but it was cut before and still ran and apparently only helps with cold start...

any help would be appreciated!

thanks!

Link to comment
https://www.sau.com.au/forums/topic/459036-no-injector-pulse-help/
Share on other sites

its definitely something not telling the injectors to pulse but I don't know what, as all the body relays are clicking they have constant 12v and I can make them click, when I crank the engine I can hear them click as well but when I look in the bores there pretty dry cant see any spray coming out... but that's whats got me stumped as when I turn the CAS by hand everything clicks but it doesn't make the noid light come on, so is that they havnt got enough power coming to them???

they all look pretty good, the main ones are the one that's on the plenum near the water neck, then the earth strap one and the fuse box one, then they all seem to come to a brown clip next to the ECU. What actually grounds the ECU, pin number 60 or whatever? I still don't understand how the noid light doesn't come on under cranking but does come on when turning by hand? As if its coming on by hand doesn't that mean the ECU has to be connecting the earths?

I just put another hose from my fuel reg into a bottle and in two key on prime ups it filled up a large dare ice coffee bottle 3/4, does this seem like too much? maybe the regs f*ked and not holding pressure enough, still doesn't explain the injectors not pulsing properly...

If you've changed the plenum and havent pluged in the AAC then why dont you fix that and see how it goes?

Have you tried pulling out a coilpack and sitting a spark plug in it and seeing if it actually sparks when you turn the CAS?

If it will spark then you will assume there is enough spark there to at least start and idle the car.

EDIT: For some reason I thought this was about no spark. I'll leave my post here anyway as it might help

Edited by 89CAL

Yeah during this I went and plugged in all the clips on the aacv still nothing. Coil packs have heaps of spark there making an arc like 3cm long can hear them all going off as well. It really seems to have something to do with when I spin the CAS by hand, I'm talking quarter of a spin hear a click noid light comes on, makes another click spin the CAS light comes on again. As soon as I try and spin it at some kind of continuous speed the light comes on once then not again but I can hear all the jecies clicking away. It makes no sense as I haven't really changed anything.

The click is coming from under the plenum I can hear it echo through it but the only thing there is my knock sensors, aacv, that solenoid thing underneath (which isn't hooked up yet but its on some kind of timed relay, that isn't controlled by the ECU and people just delete it in general) and an oil pressure sender and starter motor. So I dkno if the click is just a start up thing of the aacv to help get the engine going and every time I stop spinning the CAS it thinks the engine is off and everything resets???

ill take a video tomorrow as its hard to explain but its too dark atm..

ok so how do I test for this besides getting another one? I cut open almost the whole engine loom today to see if there is a split wire or something but no luck...

how do I tell if the ECU is f**ked? There's no light coming on but there's power coming into the ECU and that ECCS relay. I tried twisting the screw inside to the right to see if the flashes would show up but nothing.. would be really helpful if I could get that diagnostic mode to help!

would the coil packs fire if the ECU was dead?

Edited by Franko07

so I think I found the problem when I bought my car it had already had the wiring converted from rb20 to 25 turns out someone thought they were handy and soldered my CAS wires together by putting them inside straws and Aralditing them together wtf? never seen anything like it! so that's why the noid light was only coming on sometimes as when I was turning the CAS it was just by chance me wiggling the wires they would connect.

so she starts now, thanks for the suggestions!

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

    • Yuck. But it's kinda the same principle, moving timing around to make car run bad but sound good.... I went for a more spirited tuning drive to iron out a few things. Car no longer stalls, and it loved to dip RPM low when you clutch in. After tuning this (and the 4-5 tables that HPTuners/LS1 OEM ECU wants for idle air correction) it's now behaving somewhat normal. All expected because there's a new TB, new Intake manifold and that new TB which is 102mm vs 78... has an entirely different IAC passage which is smaller because ????? Unfortunately at this point I went to make further fine tuning changes to avoid it flaring up, you know... _tuning_ the HPTuners dongle died. Well to be more accurate - The USB cable died in a fashion that anyone who has ever charged a phone will recognize. After the app demanding I resync it 50 or so times (which all 'succeeded' but all failed) the device does not want to sync and I've logged a ticket with support to see if it's fixable. US Support said it was a 'storage issue' but after removing the SD card inside it and formatting it/fixing it the issue does persist. Unfortunately usually the fix is "Turn in your old dongle and pay $700 for the upgraded one" it's cheaper because I get some free licence credits I unfortunately don't need. However I'm 10 minutes down the road from HP Tuners AUS/VCM so at least I won't need to post it, and logged a new ticket for support over here. Definitely drives different. My SOTP dyno believes it's probably making 310-320kw instead of the 280 before.  It scrambles for traction a little now whereas it previously different. It drives like a bigger cam car up top even though the cam is smaller, likely due to the cam not being advanced 6 degrees. The timing is deliberately low and the fuel is very rich so who knows if this will improve on the dyno. It may, imperceptably. Also funny is removing the pineapples definitely makes the car squat more and axle tramp less. So this behavior of having more top end, squatting more, and scrabbling for traction more makes me think = more power. But I could have just been sitting on the threshold of that kind of behavior before. Time will tell if my butt dyno is calibrated right. I need the exhaust leaks fixed before dyno tune for obvious AFR related reasons - I repositioned the pipes but I'm not confident it's fully sealed even if it is better. At least the car does drive around while I cannot tweak/tune it for now. And I have aircon again. medium success!
    • Don't use that manifold. Please don't use that manifold. Sunk cost fallacy is not worth the later pain. None of these will be relevant to the change that will come from the different turbo and manifold. As in, the effect of the exhaust will be nil, regardless of what else is changed. And all the cam and fuel system stuff is not changing either way, so has no effect. The turbo and manifold (and to a small extent the wastegate)....big change.
    • Just wanted to say thank you for your input   my man (lead mechanic by trade) and I have done a heap of work as you can imagine just to make the hot side work with the dump pipe, stupid massive intake on turbo, trying to get the waste gate on was not fun.  I’m kinda getting to the point where I don’t know if I try and make this work and not throw all this cash and time away or do I scrap the lot and start again? the Apexi I’ve got was tuned for a few slight differences:   Tomei pon cams (mine are stock neo) Turbo smart 38mm external waste gate (mines 45mm replumbed) with stainless screamer pipe  3inch turbo back exhaust with high flow cat Sard 800cc top feed injectors Sard adjustable fuel pressure reg    
    • Out here E90s are the cheapest way into a sporty-ish car because everyone knows just how expensive the repairs can get. 8-10k USD for an automatic 335i. 
×
×
  • Create New...