Jump to content
SAU Community

Rb20 Won't Rev, No Boost, Easy To Stall. Whats Going On ? With Vids

robots

By robots,
in Engines & Forced Induction

 Share

Recommended Posts

robots Experienced

robots

Posted
Posted (edited)

Hi!

My rb20 is playing on me. Yesterday I went for a drive.

Car was ok for pretty much whole time, normal driving, could boost etc.

Than I tried to have a speed test with s14 sr20det from.

Turned on my boostcontroller, installed recently. Profecb, tuned to 0.6-0.7 at 1,2,3 gear. Standing, 1,2,3(gave it some revs), go. 1 st gear pulling, 2nd gear car jurks, no boost. I stop immediately. Idle revs not stable, can't drive a car at all, no power under load. Checked all the hoses, seemed fine and in place. Vacuum at idle : -.7 bar, can rev but with some misfire around 2k.

Revs stable at idle.

Than I turned the engine off to let it rest for a bit. Turned on again in 10-15 min, same. Puffed some black smoke when I put in 1st gear and gave it some revs just to move. On the road home I had to built some revs, around 2-3 k and engage the clutch to make it drivable, without doing it it woulnd't built revs with WOT at all, just drop rev and stall.

Came home hooked up consult, no errors - code 55.

Unplugged AFM, 2500 limiter.

Here are some vids shot yesterday and today.

It was a bad idea to get out of the basement park with such problems, but had no choice, had to do it anyway.

Yesterday consult:

http://www.youtube.com/watch?v=Touv0v_TSko

http://www.youtube.com/watch?v=Krp-y-Fc8tA

Today revs under load, driving:

http://www.youtube.com/watch?v=E3Xf99kv0g0

http://www.youtube.com/watch?v=xxD_TbGoR5Q

http://www.youtube.com/watch?v=HGowIKq2JGw

http://www.youtube.com/watch?v=HGowIKq2JGw

http://www.youtube.com/watch?v=a1vcYxoasiU

http://www.youtube.com/watch?v=Wdu9lumNuuc

My ideas:

Fuel pump. (I have bosch 040, maybe it died ?) shows 2.5 bar at idle. Like it should.

AFM died ?

Timing belt jumped a tooth ?

.Sorry for my english LOL.

Looking forward for some ideas.

Thanks!

Edited by robots
robots Experienced

robots

Posted
  • Author
Posted

I looked at all the piping and it seems to be all in place. If I understand correctly it won't idle ok and it won't show -.7 vacuum at idle. As no piping - leak, unregistered air is going in.

cheez Mentor

cheez

Posted
Posted (edited)

have u checked ur afm? also wat mods u got on the car? its hard to say when we dont know whats been done to it?

also black smoke could be a turbo? correct me if im wrong, but if you blow the turbo, the car will still run but no boost yeh? shot an exhaust wheel??

Edited by cheez
robots Experienced

robots

Posted
  • Author
Posted (edited)

Mods: stock engine, fmic, stock exhaust, bosch 040 fuel pump.

I checked the intercooler piping and its seems intact. I will go have some fun with my car today. Maybe go get another AFM.

Edited by robots
robots Experienced

robots

Posted
  • Author
Posted (edited)

Ok, I've managed to get my engine boosting and reving again. Problem was with the the pipe from the afm to turbo, air leak. And from intercooler to intake plenum. They all had air leaks once on load. Strange. Than after I get rid of that problem, car became driveable. But doesn't pull as hard as before. Didn't try with the boostcontroller yet. Also turbo now got that flatter sound. And I also get backfire when I change gears. I was like wtf ? Also there was some oil in the turbo>intercooler pipe. Cleaned it.

So now car boosts, has mad turbo flatter sound, doesn't pull as hard and gets some idle rev issue when u back of the throttle or press brakes.

Any ideas ?

Will post vids later.

Edited by robots
robots Experienced

robots

Posted
  • Author
Posted (edited)

Boosting again.

http://www.youtube.com/watch?v=lTYpV9mc1bY

1st gear pull and really loud bang/backfire. It was like gun shot.

Had little fuel in the tank at that moment. So I had something like a fuel cut after that backfire. Damn it :x

http://www.youtube.com/watch?v=jC_ZxgPEe_c

Exhaust note at idle after the backfire bang.

Now I got some drone sound in the downpipe area. Maybe I shot of a turbo exhaust wheel ? :cheers: :?

http://www.youtube.com/watch?v=xyck4sARUe4

And some fun, doing some donuts a week ago.

http://www.youtube.com/watch?v=KFE8Xzy8wBU

What I got now:

1)Engine can rev, make boost.

2)Got mad turbo flatter sound now.

3)Got rid of most air leaks I guess.

4)Car doesn't pull as hard as before. Or I just forgot how it pulled already.

5)And I get backfire bangs nearly every time I change gear. It even backfires on idle, when I rev it and lift off the throttle.

When I was looking for the air leak in intercooler piping, I found some oil build up in turbo>intercooler pipe, wiped it off.

Edited by robots
Daniel R32 Experienced

Daniel R32

Posted
Posted

I had oil all through my piping and exhaust when the seals in my turbo blew, so maybe that has happened.

Not too sure bout the backfiring but when my 32 was still N/A i had alot off backfires or 'pops' as i changed gear and some times when i changed down

The turbo flutter could be from a BOV that isnt opening and pushing out the air back through the turbo (oil in the piping might have gotten into the BOV and is making it harder for it to open). also if there is oil leaking through the inlet side and into the motor that may aslo be holding back some power, and not letting it feel like it is going as hard

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

    • MBS206
      Nismo coppermix twinplate clutch

      By MBS206 · Posted

      Is there a diameter difference in the stock to Nismo? If so, the weight alone won't be indicative when comparing flywheels of the same diameter, since the radius of the flywheel acts on the moment of inertia with a square factor, where as mass is linear. Roughly going from a 4.5kg flywheel with radius 20cm, to a 9kg flywheel with radius 14cm would see them act the same. This calc is just here to act as a brief numbers comparison and reflects no actual RB flywheel diameters etc. it also assumes even weight distribution (thickness) throughout.
    • MBS206
      Rob's S Chassis track cars. Now with more s15 and less 180sx

      By MBS206 · Posted

      It seems this could be due to a restructure/team direction change... Or... You're working with a different category of vehicle... Or you've decided you'd rather be able to play with your own cars again...   I'm hoping the latter...
    • robbo_rb180
      Rob's S Chassis track cars. Now with more s15 and less 180sx

      By robbo_rb180 · Posted

      had 4 weeks off over xmas and well did some stuff to the shed and BRZ, well short of is I don't work full time in supercars anymore as of yesterday.........
    • MBS206
      Rob's S Chassis track cars. Now with more s15 and less 180sx

      By MBS206 · Posted

      Did you get any down time over Christmas, or have you had any since to play with this? Or have you given up and are trying to get yourself a second hand V8SC instead?
    • MBS206
      High temp brake fluid?

      By MBS206 · Posted

      A random thought I had just before I hit "Submit on this post". If brake fluid, in a container in my garage that has never been opened goes bad after 18 months, why can I leave it in my car for 24 months in an "unsealed container"... Secondly, some other digging, and brake fluid manufacturers seem to be saying 5 year shelf life... Me thinks there line on 18 months for an unsealed bottle is pretty much horse shit marketing spin. Kind of like how if you drive a car and don't run a turbo timer your turbo and motor will die horribly...   Where I started on this though... Someone (me) started down a bit of a rabbit hole, I don't quite have the proper equipment to do Equilibrium Reflux boiling per the proper test standards. I did a little digging on YouTube, and this was the first video I found on someone attempting to "just boil it". This video isn't overly scientific, as we don't have a known reference for his test either. Inaccuracy in his equipment could have him reaching the 460 to 470f boiling point range in reality. In the video, using a laser temp gun, he claims his Dot3 that's been open in his florida garage for over a year gets to about 420 to 430 fahrenheit (215 to 221c) Doing some googling, I located an MSDS for that specific oil, and from new, it claims a dry boiling point of 460 to 470f. Unfortunately they don't list a wet boiling point for us to see how far it degraded toward its "wet" point. While watching it I was thinking "I wonder what the flash point is..." turns out its only 480f for that specific brake fluid....   As for testing the oil's resistance, I might not be able to accurately do that unfortunately. Resistance level will be quite a LOT higher than my system can read I suspect based on some research. However, I might be able to do it by measuring the current when I apply a specific voltage. I won't have an actual water % value, but I'll have some values I can compare between the multitude of fluids. I'll run some vague calculations later and see if I should be able to read any reliable amount of current. These calcs will be based on some values I've found for other oils, and see how close I'll need my terminals together. From memory I can get down to 1pA accuracy on the DMM. I don't think my IOT Power Tester has any better resolution.    
×
×
  • Create New...