Jump to content
SAU Community

Recommended Posts

Car is R34 GT-R.

Installed these and car ran briefly with only a correction factor change (set at 48%) but I'm not sure what the latency should be. The car wants to start and almost does.

Other factors to consider, also installed Walbro 460LPH pump with direct battery feed via relay. Have confirmed there's fuel in the rail and that the pump is priming/supplying fuel and getting full voltage.

I bought the set from Kudos which come in a Sonic Performance bag and have part number BSS1000.

Closest I've found is this but I'm not sure what voltage the 34 runs as per that table - http://nyet.org/cars/info/ev14-latency/1000cc.png

Why?

Or, organise the tuner to come to you and set the settings and do some road tuning before the dyno.

Or, drive to tuner on current injectors and baby the car. Change injectors there. Retune.

do you have a wideband?

scale the injectors to the right percentage then set the fuel map where it idles at around 100, now adjust the latency on the fly till the idle afr is at around stoich

Take into account the injectors are not connected to the same pump as before on same voltage now.

Your new pump is hard-wired to battery now meaning the first 2 load cells @ idle will need even less duty cycle again as the squirter is under more rail pressure now.

Latency settings need to be correct before starting the car.

Your plugs will now be wet.

I Wouldn't be touching a single adjustment on a ecu without wideband connected.

It's like crossing the motorway blindfolded.

Edited by mr skidz

I got the car started last night after leaving it for a while, but I put the PFC settings back to where they were - which should have been way too rich. It didn't want to rev cleanly and would hunt after dropping back down from revs. I turned it off and the penny dropped. These are high impedance injectors...

Is there a generally accepted way to remove the resistor block?

Edited by ActionDan

Just to get it to the tuner. No big deal if I can't will tow it. I always like to have a go where possible.

I wouldn't think it would have any effect other than giving less voltage due to increased resistance in the circuit. (My ohm's law memory is sketchy but I thought higher resistance meant less voltage and given the injectors are being fed through the resistor block, will be seeing less voltage than they want).

Which will be why the car actally ran with the injector percentage scaler put back to stock in the PowerFC.

When I spoke to Sonic Performance they said it won't have caused any damage but the injectors won't flow properly until the resistor is removed.

Ahh, lower current not voltage. cheers.

Either way, less amps isn't going to "hurt" the injectors as far as I'm aware?

Edited by ActionDan

Read that something fried on an RX7 doing the same thing I think they fried the ECU not sure how but I read it last week on the RX7 forum it was in regards to the ballast resistor someone left it in when they should have removed it.

Take into account the injectors are not connected to the same pump as before on same voltage now.

Your new pump is hard-wired to battery now meaning the first 2 load cells @ idle will need even less duty cycle again as the squirter is under more rail pressure now.

I don't believe that statement is correct... the job of the fuel pressure regulator (FPR) is to control rail pressure.

Regardless of what the fuel pump OR fuel pressure being pushed into the rail, the FPR will control the rail pressure to maintain 3 bar of fuel pressure going into the motor (taking into account the plenum vac/pressure).

The only instance where the fuel pressure is all over the shop (using the factory regular) is when there's so much flow it cannot return fuel quick enough.. usually caused by running surge tank setups with twin pumps.

Can't imagine it doing damage to components, injectors may not operate 100% properly maybe?

The resistor pack was just to fool the ecu thinking it was driving high impedance injectors. It was the fashion at the time.

I don't believe that statement is correct... the job of the fuel pressure regulator (FPR) is to control rail pressure.

Regardless of what the fuel pump OR fuel pressure being pushed into the rail, the FPR will control the rail pressure to maintain 3 bar of fuel pressure going into the motor (taking into account the plenum vac/pressure).

The only instance where the fuel pressure is all over the shop (using the factory regular) is when there's so much flow it cannot return fuel quick enough.. usually caused by running surge tank setups with twin pumps.

you are right. I went back to edit my brain fart but I'm flat out busy at work right now ;/

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

    • I'm normally copping my own abuse from neglecting my daily drivers. "Those suspension bushes will last a bit more", "Don't worry about the oil leak, just keep topping it up". The project cars I'm always doing things slowly on them as I'm wanting them to be done better, and neater, and nicer. Luckily I don't have to deal with 18 year old Matt's "Learning to wire" stuff in the project cars. And there's only one piece of wiring I'm displeased about in the Landcruiser, and it's about to be cut out... However, the box loads of parts that have been going through this place lately for the Landcruiser... Brake pads Brake Rotors Full handbrake overhaul Wheel Bearings Seals Swivel hubs Steering Boxes Half the suspension joints Shocks Air bags (Ones to go in the rear springs for towing) Water pump Timing kit Lower timing case Harmonic Balancer Radiator Lots of other little seals and shits Gas struts for the bonnet New power window switches And god knows what else I've forgotten... Ha ha ha I have my fingers crossed the pinion seals don't start leaking on the diffs, that the transfer case doesn't leak, and the gearbox input shaft doesn't leak, nor the rear main seal. As they're about the only seals I haven't replaced in the driveline! I'm seriously eyeing off buying new caliper rebuild kits front and rear brake calipers... I'll probably recheck all the valve clearances soon too, and hopefully, it should be all good and sweet to haul some long distance trips again!
    • Every time I pull my 3x gauges out of the console and see the crack-addict way that I did the wiring, and I just can't bring myself to tear it all apart and "make it nice", because it is currently working. In fact, the last time I was in there I probably made it worse.
    • The best part is when you own the car long enough that you look back and find your OWN ham fisted amateur shit!
    • The annoying part about neglect, is when you start to replace one thing, and find ten more broken things. Ham fisted monkey repairs you normally only find out about when trying to do something unrelated! Ha ha   Neglect you can kind of anticipate the huge costs to fix it all. Ham fistedness is normally a shock the first time your work on a new old car, as everything "looked" good before.
    • For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
×
×
  • Create New...