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Recently installed sard 540cc injectors in my R33 gtst and I can't make it idle properly

It's pretty hard to crank the car over, idles real rough and rich, if I rev it a little it would pop and sounds a bit like a wrx

The Sard 540cc has latency of 1.6ms (!!), I thought thats a bit high but its the value I got from SARD website.

The ECU I have is PFC, the value I've entered is

370/540x100%= 68.5%

lag time was 1.6- 0.528= 1.072 - but power FC only allows maximum of 1ms lag time so I could only enter 1.00ms.

Is this the reason why it's not idling properly? being 0.07ms out

Also tried other latency settings, the car would not start with latency value, like 66 or even 30

is 0.07ms out bad enough to cause this? Do i need a different ECU? or are there ways to get around this?

any help is much appreciated

btw here's a link to SARD's website, the white 540s are the ones I've got

http://www.sard.co.jp/after_eng/products/engine/injector/injector_syasyu.html

Edited by chiksluvit
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https://www.sau.com.au/forums/topic/447298-sard-injectors-and-pfc/
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read it many times, pretty sure I've got the calculation right

followed it and cross checked it with the PFC instruction manual, didn't answer my question.

Can anyone confirm that I'll be able to add more than 1ms injector lag time using datalogit? I know you can do lag vs battery voltage just not sure about degree of adjustment

Edited by chiksluvit

does 0.07ms make that much of a difference? in saying that i have also tried different lag times and they do seem to affect the idle (gets worse as I decrease the value).

or am i looking at the wrong thing altogether, could it be a binding bottom O ring that is leaking fuel into the cylinder causing this? although I've left the car in idle for more than 10min so if it was a leaking O ring the engine would have hydrolocked by now?

the injectors are brand new and so are the O rings that came with it, used sillicon spray on the O rings during installation

there's no visible leak from the top

Got them from a forum member at an ok price, was being cheap, didn't want to pay 1/10 of the cars worth for a set of new nismos

Though I was thinking if I enrichen the idle area it still doesn't really fix the other zones. Doesn't rev clean with the way it is now. Ie stupid rich with pops when I rev it a little in neutral

Edited by chiksluvit

The cheap man pays twice... As you just found out.

Any Sard injectors will have similar issues, and they get worse the larger they are.

I can get new 550cc sidefeeds to suit the 33 that will run fine, but that is the largest they can supply. For anything else you will need to fork out for genuine Nismo's, or swap to a top feed setup which work out around the same price.

The cheap man pays twice... As you just found out.

Any Sard injectors will have similar issues, and they get worse the larger they are.

I can get new 550cc sidefeeds to suit the 33 that will run fine, but that is the largest they can supply. For anything else you will need to fork out for genuine Nismo's, or swap to a top feed setup which work out around the same price.

speaking to the converted :)

Yeah had them 550ccs before on my old car and they pretty much fired up straight away without any issue, so I thought the 540s Sards would also be ok.

I thought sard discontinued them 550s now? That's what it says on their site

Will try the settings on the ecu first I guess

does 0.07ms make that much of a difference? in saying that i have also tried different lag times and they do seem to affect the idle (gets worse as I decrease the value).

or am i looking at the wrong thing altogether, could it be a binding bottom O ring that is leaking fuel into the cylinder causing this? although I've left the car in idle for more than 10min so if it was a leaking O ring the engine would have hydrolocked by now?

the injectors are brand new and so are the O rings that came with it, used sillicon spray on the O rings during installation

there's no visible leak from the top

what you'll find is that the manufacturers dead times should be used as guidance only....you can hear when you have the latency wrong and adding more fuel will not make this better...it'll just change the afr's. I would suggest adjusting the dead time correction untill you get a decent idle...you can do this with the car running. e.g my 850cc side fed injectors had a written latency difference of 0.26 but i found 0.31 was the better point...dead times will change with the age of the injectors also. A tuner could set this best for you using an FCdatalogit. The hand controller may not allow going past 1 but the fcedit software can. The other way to do this is to change the inj latecy vs battv. 0.528 is the 14volt latency for factory but is your car running over 14volts at idle....something to check.

Edited by Badgaz

run E85 lol

will need higher pulsewidth to get things going

Nuh that'll kill the bosch fuel pump in no time plus they don't exist around my area lol

Yeah yeah I know my whole fuel system is a dinosaur lol

Edited by chiksluvit

Unfortunately I don't have either of those or know anyone who has one of those that I can borrow.. would take up your offer but

just curious that whether incorrect latency settings will also affect it when the engine is revved in neutral?

It is rough, wrx-ish and pops when i rev it in neutral

If latency setting only affect idle, then the engine being rough and popping when i rev it a bit in neutral could be because one of the bottom O-rings not sealing properly?

seeing that a few 300zx and s15s have used the same SARD injectors on some japanese blogs, I didn't think these injectors would be a problem on r33s at all

Edited by chiksluvit

If latency setting only affect idle, then the engine being rough and popping when i rev it a bit in neutral could be because one of the bottom O-rings not sealing properly?

it's more so it's missing or not supplying enough fuel because it has fallen off the linear scale.. try blanketing more injection across the map in the temp setting menu

Latency problems show up at idle more than at load because at idle the pulsewidths are very low. If the latency is wrong then you can end up with a small fraction of the proper pulsewidth, or maybe twice as much pulse as you need. That same 1ms error, when added onto a 8 or 12 ms pulsewidth under load, is not as significant. It still makes the fuelling wrong, but it is not as noticeable. So it will run (with some load), just either a bit too rich or lean, but it may not idle.

Edited by GTSBoy

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