Jump to content
SAU Community

Recommended Posts

My car was stolen a few weeks ago and I was fortunate enough to have it found a few suburbs away. A few bits and pieces were stolen including a Dual Stage boost controller and my SAFC. Since the car was stolen when i try to drive/rev the car it splatters at about 2000-2500 revs. At first I thought that it was the hoses that were left hanging from where the boost controller once was then i reconnected them but the problem remained. Since then I thought they could have boosted it too high and stuffed my turbo then i thought of the BOV and also the wiring to the ecu(its practically hanging on the ground now). But last night i thought about my spark plugs. I had an order placed through NGK for suitable iridiums for my RB25DET and they sent me 1.1mm gaps which I was pretty sure was wrong but they worked when i put them in so i left it like that. When the SAFC was taken out because the fine tuning was gone could that in conjunction with the spark plugs have caused the problem???

Or are there any other ideas

(Air exits back through the pod filter i think because the valve on the BOV hasnt had enough force to open it.)

Link to comment
https://www.sau.com.au/forums/topic/37814-rb25det-splattering-please-help/
Share on other sites

Sounds like the car may be in 'limp home mode'. this could be due to a fualty connection coming out of the ecu, AFM not plugged in or working properly or a few other things.

check your afm connection, check the ecu is plugged in properly, check none of the wires from the SAFC being disconnected are causing an earth. make sure all the hoses are plugged in. then do an ecu reset.

If all this fails to rectify the problem, run ECU diagnostics, which may shed light on the problem.

1.1mm gaps with the stock coils aren't real boost-friendly, but shouldn't be causing problems at 2500rpm. A stuffed turbo shouldn't cause the problems you describe either.

Things I can think of:

1) Bad tuning (possibly due to parts being taken off), which is unlikely unless you have different cams or something because without the SAFC it'd just be running the stock maps

2) You've missed some of the pipework or a hose has popped off somewhere

3) Some of the wires going to the ECU are either disconnected, or are shorting out. Quite likely as they would not have been particularly careful when removing the SAFC and, as you say, your loom is 'hanging on the ground'

When you say that it 'slatters at 2000-2500 revs', do you mean it won't go past there, or it's a mess from there on, or that there's a bad spot about then which clears up for the rest of the rpm range?

Disconnect the battery, and either leave it overnight, or stand on the brakes for (to be safe) 30 sec or so. Reconnect the battery, and voila, your ECU has forgotten all its 'tweaks' that applied when the SAFC was connected.

The exact same thing happened to me about a year ago. You need to rewire(return the wiring to its original configuration) the ecu, or remove the wire remining from the safc. Your standard ecu still thinks the safc is connected and hence the dodgy signals being sent to the ecu. Unfortunatley i cant tell you exactly how to do this because i had my mechanic fix the problem at the time.

The reason why the car is spluttering so hard is because your ecu is overfueling the engine.

Hope this helps,

Jason

the AFM wire on the ecu is cut when installing a SAFC, to intercept and adjust it, it is not spliced like the rest. Have you shorted the AFM wires together after the SAFC was stolen? If not, then your ECU thinks your AFM is not connected / fubar so it is in limp home mode.

I'd be taking it to an auto electrician to have them check the wiring loom near the ECU out, rather than have you mechanic do it. I have no idea how good/bad/otherwise your mechanic is, but for electrical problems, particularly if they aren't familiar with the car, I would always take it to a leccy.

CroatianR33, Zahos is right.

It's DEFINITELY because of the AFM wire was cut for the signal to be routed into SAFC and out again to your ECU. Since your SAFC is stolen, that wire is now disconnected/left open. Find the installation diagram of your SAFC to find out which wire was cut, reconnect both ends of that wire and it will solve your problem.

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

    • Bit of a pity we don't have good images of the back/front of the PCB ~ that said, I found a YT vid of a teardown to replace dicky clock switches, and got enough of a glimpse to realize this PCB is the front-end to a connected to what I'll call PCBA, and as such this is all digital on this PCB..ergo, battery voltage probably doesn't make an appearance here ; that is, I'd expect them to do something on PCBA wrt power conditioning for the adjustment/display/switch PCB.... ....given what's transpired..ie; some permutation of 12vdc on a 5vdc with or without correct polarity...would explain why the zener said "no" and exploded. The transistor Q5 (M33) is likely to be a digital switching transistor...that is, package has builtin bias resistors to ensure it saturates as soon as base threshold voltage is reached (minimal rise/fall time)....and wrt the question 'what else could've fried?' ....well, I know there's an MCU on this board (display, I/O at a guess), and you hope they isolated it from this scenario...I got my crayons out, it looks a bit like this...   ...not a lot to see, or rather, everything you'd like to see disappears down a via to the other side...base drive for the transistor comes from somewhere else, what this transistor is switching is somewhere else...but the zener circuit is exclusive to all this ~ it's providing a set voltage (current limited by the 1K3 resistor R19)...and disappears somewhere else down the via I marked V out ; if the errant voltage 'jumped' the diode in the millisecond before it exploded, whatever that V out via feeds may have seen a spike... ....I'll just imagine that Q5 was switched off at the time, thus no damage should've been done....but whatever that zener feeds has to be checked... HTH
    • I think Fitmit had some, have a look on there (theyre Australian as well)
    • Hah, fair enough! But if you learn with this one you can drive any other OEM manual. No modern luxury features like auto rev-matching or hillstart assist to give you a false sense of confidence. And a heavy car with not that much torque so it stalls easily. 
    • Actually, I'd say all three are the automatic option. Just the different trim levels. The manual would be RSFS, no? 
×
×
  • Create New...