Injector compensation on PFC ??

[B-Man]

Getting different opinions on what is the correct injector compensation when running 550 cc per min injectors with the PFC.

Some say 80%

Some say 370cc / 550cc = 67%

What's the go ??

Cheers.

[jnr32r]

67% for a R33 is about right.

But in a R32 that has 270cc std injectors its more like 50%.

It all the depends on the tunability.

[Steve]

B-man, what rail pressure are you running? this will make a difference.

EG, sard 550cc injectors are rated at 3.0kg rail pressure, at 2.55kg (stock nissan) they are only 510cc.

your formula is basically correct though.

Also, make sure you adjust injector lag time. If you are running Sard 550cc, it is around +0.08ms

how is the idle going? - I forgot to mention on your idle question thread, but have you tried lubricating the AAC vavle? I sprayed a fair bit of WD40 around the adjust screw and it certainly helped (wound in the adjust until the valve was working overtime to control idle, left it go for about a minute, then would the screw back out and it settle things a fair bit:))

[Steve]

oh, and I found around 68.5% works best for me (injector correction) that is with bosch 044 pump and stock fuel rail pressure - which is probably slightly higher than stock with the larger pump.

[B-Man]

I got basically same setup as you Steve - Standard Rail and Bosche in tank pump (044, I think)

Idle issues still there but haven't looked at it much as gotta get the PFC tune right.

[Chris32]

Sorry to dig up such a old thread

Where is the injector correction located on the hand controller?

I am installing some 440cc into my R32 and need to change the injector correction so its at least drivable to get it tuned?

My plan is set the PFC to default, and then add the injector correction so it will hopefully be drivable

Any info much apprieceated

Chris

[Trust33]

chuck it on a trailer and take it to your tuner.Dont risk something like that its only a lean out away.

Unless you are definent i wouldnt try.Sorry if i sound callas but hey.

[R31 POWER]

Mine is at 60% Chris and I'm sure it is on standard fuel pressure coz I set the nismo fuel reg at stock pressure,that is unless when I got it tuned they wound more into it.

What I noticed with the standard tune on the PFC and gtr injectors was it ran very very rich and did'nt mind the extra fuel when cold but as soon as it got some heat into it it missed coughed and spluttered and stalled.

So as a fix so I could get it to the tuning shop I went into the ign/inj correction settings and put the inj to 0.650 and it was still rich but safe to drive.

[Steve]

R31 is on the money, the INJ/IGN is the one you want - just divide the stock injector capacity with the new injector capacity, the resultant 0.xx will equate to the percentage you will need.

Also, you have an "injector" menu, you need to put in the correction there too - this is for closed loop (idle, cruise) and cold start correction - you will also see a lag correction, if you have a look here: http://www.ap-engineering.co.jp/el/inj_top.htm from memory they have the lag times and injector capacities for stock (and aftermarket) injectors including the relevant fuel rail pressures. The lag correction is to make sure the injectors fire at the right time.

Most tuners I have been to dont even seem to realise it is there, but it made a big difference to idle and cruise with my 550cc.

Oh, and lastly, the IGN/INJ correction is volatile, so when you stop the car, you will have to re-enter the correction until it is tuned. Its a very handy feature for the ign side of things too - if detonation is up a bit, on a hot day, bad fuel whatever, just pull a degree or two across the map to prevent expensive problems.

Dont be scared to do the correction and drive the car - just dont thrash it and keep an eye on the knock.

GL

[Steve]

OK, just looked it up, correction is 58.0%, lag correction is -0.15ms - have you got resistor packs as well? you need an extra 12ohms per injector.

[R31 POWER]

Yer resistor pack is in.

[Chris32]

Cheers guys, looks like a work around thats not too hard

At least it should get me to the dyno etc

I just found a english PFC hand controller manual which takes you through pretty much everyhting you need to know, i will post a link when i can find it again!

Chris

[Beer Baron]

I just found a english PFC hand controller manual which takes you through pretty much everyhting you need to know, i will post a link when i can find it again!

Please do!

Richard

[Chris32]

Please do!

Richard

here it is - http://www.scuderiaciriani.com/rx7/power_FC_manual.pdf

enjoy

Chris

[Beer Baron]

That's good but unfortunately as it's for a 13B a lot of the stuff isn't relavent. Does anyone have one for the RB26DETT?

Richard

[Chris32]

That's good but unfortunately as it's for a 13B a lot of the stuff isn't relavent. Does anyone have one for the RB26DETT?

Richard

Apparently thats the only full english manual out, as it was done for the american market

Let me know if you find any other manuals

There are quite a few on www.apexi-usa.com

Chris

[Beer Baron]

Will do, thanks mate

Richard