Jump to content
SAU Community

Recommended Posts

Hello,

So at my last track day a couple weeks ago everything was going fine but after a couple sessions all of a sudden when i was pulling into the paddock, my car would not idle at all and had horrible misses below 2k rpm. Everywhere else in the rev range it ran fine an did not break up. Now I've done some testing so I went with the simple stuff first: plugs gapped right, r8 coils(deletes the ignitor). That did nothing. So then i replaced my coolant temp sensor and checked tps voltage, that fixed the idle issue. So I went to check my timing. With the light the first time i checked the marks were so far past advanced that it would have been blown up by now, so I was confused and shut the car off to have a drink. Came back and started it up again to look and now it was a little past the last mark at 30* degrees and was able to get it to 20, with the cas retarded almost all the way it allowed me too. I then went for a test drive and the car ran fine but when pulling it out of the driveway it died. I pulled it in to check the timing and it was the same at 20*. So i went to drive again and got out on the road and got on it, it reved up fine and built boost with no missing, but felt like it had legitimately zero power, and off throttle it gurgled a bit. I replaced my cas and that changed nothing. I'm stumbled at this point. Any pointers??

Thanks for any help. 

Link to comment
https://www.sau.com.au/forums/topic/477679-weird-possible-timing-issue-20det/
Share on other sites

Check for a slipped crank pulley. The timing marks could be telling you lies.#1 plug out and screwdriver down the hole looking for TDC would be the first step there.

Remember that an RB20 has a switch in the TPS for idle. It doesn't rely on the ~0.45v that the 25s do.

Otherwise, your weird issue is weird and will always be something unexpected!

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...