Slow Revving Rb20

[rso84]

Just fitted another RB20 to the cefiro, it starts first turn, idles perfectly and smoothly, the problem I have is that it rises thru the rev range slowly - like it has a blocked Cat or something, but exhaust is straight thru system!!!

Have replaced injectors, plugs, AFM

ECU Diagnostics show "55" (a first for my car!!!)

any help leading to the solving of this problem will lead to a cash reward!!!

[rso84]

I have adjusted the CAS in both directions, and notices no improvement, only worsening of the situation

[Pauly33GTS-t]

is this stupid suggestion but what ECU and etc are u using to run the car?

[James_03]

he is most likely running oem ecu as thats what the error code is from.

Have you reset it yet? If not I would be trying that first.

[rso84]

stock ecu - has been reset heaps!!!

[GreddyGo]

Sounds like there is def a restriction, intake/exhaust/turbo

What mods have u performed?

What flywheel and clutch assy are u using?

[gtst25]

Stupid question BUT have you replaced the airfilter? My dad and I did a rb20 conversion in to a r31 - it had no go at all - the airfilter looked ok but we changed it and straight away you could hear the turbo and it had some go.

Cheers

[123456]

Replace the filter then check the fuel pressure/flow. . Mine revved slow because of a dead pump

Edited January 13, 2007 by 123456

[rso84]

mines got a fairly new walbro, new filter, no airfilter atm - but tried with a clean pod and was no better

[slip]

check all the intake piping. theres been a few instances of people finding rags etc in their piping.

a cam could have skipped a tooth.

timing could be wrongly set up and massively retarded?

[T04GTR]

mayby its just tired

[tmc_2]

Check the fuel filter and intake.

I had a similar problem turned out to be a compination of a not so perfect airflow sensor and a dody fuel presure regulator, apparently a suspect fuel pump might give similar symptoms.

Try and borrow a fuel pressure reg and a airflow of a working rb20 and see how u go.

[MBS206]

I'd be expecting a rag in the intake pipes, especially if you bought the "new" RB20 from a wrecker/engine builder and not just out of another car.

[Risking]

Id be checking valve timing and ignition timing.

[Ol_Mate]

might sound stupid but does the throttle butterfly open fully?? I imagine that the accelerator pedal may not be adjusted correctly for the new motors throttle...

[Cubes]

Its an rb20.. They all rev up slowly due to the lack of torque.

Have you thrown a timing light on it while you rev it?

A friends CAS was fine when setting the idle ign timing but when reving it would go massively retarded. It could be seen by throwing a timing light on to it as you rev it up.

[Risking]

Is the loacting dowl on the exhaust cam broken off??

It really does sound retarded.

Is it still making boost??

[Cubes]

If it were broken off it wouldn't run.

[Risking]

I beg to differ.

If the dowl that esures the CAS can only be fitted one way is broken off then the CAS can be fitted one spline out retarding or advancing the timing accordingly.

Im not talking about the entire spline only the small key way style dowl.

[Cubes]

The RB20's don't have splines, they run a simple half moon engagement. If this breaks then there is simply no drive to the cas.