Jump to content
SAU Community

Recommended Posts

hey all,

I have just had my motor replaced and have had some vacum leaks fixed and an exhaust manifold leak fixed. Before they were fixed car wasnt boosting up. Car is boosting up now but seems to be hesitating a bit. Doesnt seem to be comming on boost as hard.

I have added a front mount and i was told to expect more turbo lag, but the car feels substantially slower. I notice it quite a lot in 3rd gear, Second doesnt seem to bad. Idle goes up or down a bit every now and then too. I have noticed when the idle does this, I can hear a clicking near the front or intake side of the head just as the idle changes?

Any Ideas anyone?

And also what does everone sugest i do to treat my newly formed car? Good oil? etc

thanks

Link to comment
https://www.sau.com.au/forums/topic/109663-rb25det-acting-strange-help/
Share on other sites

I have just had my motor replaced

I have added a front mount

ummmm - has it been tuned as yet with the fmic on??? my rb25det was very hesitant when I put on the fmic, now after a tune is very strong.

The car has the following mods,

K&N pod filter

Hybrid Front Mount

3 inch cat back exhaust

Daikon/exedy brass button clutch

kyb struts and springs

I havnt had the car tuned after I have put motor in and the front mount so maybye that is the problem. I am confident it is not the usual coil, or spark plug issue as they are new and coils have been checked 2 weeks ago.

Noticed idle fluctuating between 800 and 100 rpm everynow and then again today. Almost sounded like it had lumpy cams.

James,

The engine is out of a series two 97 model, i didnt rebuild old motor as block was screwed.

I dont have a aftermarket boost guage. I also have performed that high boost mod mod that is stated on this site, possibly a dumb move befor car was tuned.

Sounds dumb and you've prob checked it anyway but it made my 33 idle fluctuate as you've described...

Right at the front of the fuel rail (cyl #1 end of motor) is the fuel pressure reg which has a little vac hose attached to it....this hose may have a leak or has come off....

Yeah ill try the ecu reset tmrw thanks for that. Yeah ill try injector clean too. Guy thinks that there may have been bigger injectors in the half cut i bought. May be something to look at, maybye they need better reg or pump?

it sounds like you are hitting the factory excess airflow protecition. this is usually the result of an incorrectly plumbed in actuator line. check there is a pressure line from the intercooler piping running to the turbocharger actuator (copper bubble with a nipple on it).

if its missing your are running unlimited boost and the ecu is protecting itself. what does the factory boost guage show? does it goto +7 ?

On that note of ECU's and motor swaps...

The series 2 motor doesn't run the ignitor on the top of it, it's run from the ECU. How did your mechanic get around this? Swap ECU's, or do something funky with another ignitor?

oh you have a series 1 ecu running a series 2 engine?

i once tried a remapped ecu and it was from a series 1 rb25

i experienced the same sorta things you mentioned, really flat gear feelings despite the car running fine.

please confirm what ecu you have and what engine (series 1 or 2)

if you have series 1 ecu on series 2 engine i would recommend buying a series 2 ecu

well if it in fact is a series 1 ecu on a series 2 rb25 engine (which seems to be the case without confirmation) then an safc will help a little but i suspect the problem will still be present or get worse. you would be better off getting a correct series 2 ecu.

the powerfc will fix it as the powerfc is the same wether its the series 1 or series 2 rb25, its the same ecu.

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

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...