Yet another idling issue. K value SR20DET redtop, 650cc, z32

[cheesy]

Hi
I'm trying to start my sr20det ps13 after putting in sard 650 topfeed injectors and a z32 maf on a gt2560 and stock intake.
I have also installed greddy easycams just to list my full specslist.

I cant seem to get it idling correctly.

My stock k value is 21475
I resize my injectors from 370 to 650 and get 12224
Afterwards I change my maf to z32 and then I get 21075.

Is this correct? I cant seem to get it running right.

I use the stock 580us injectortime.



Any ideas are very much appriciated

thanks

*update*

I got it idling at a k settings of 46000-50000
I consider that WAY off "the ballpark" .. :/

[BlueRB240]

I'd go higher on the lag time since it is a bigger injector. Try 800 and keep adjusting with the auto box ticked.

[PL]

I agree. Go mad on the injector latency with those injectors.

I usually start by adjusting the K constant first - just tick "auto" and then use the "+/-" keys. This will quickly tell you if you're too rich or lean.

Then give it a couple of squirts on boost to see how your full load mixtures are looking.

Then play with your latency some more.

You need to juggle K constant, fuel map figures and latency until it's just right.

PL

[cheesy]

thanks, I'll try some more to get it running.
I'm heading for a fc tuning session today, but I still need to cover 800km on my own pretune

According to sard's website, the latency are 1500uS on those injectors. Do I dare to go there?

[BlueRB240]

If thats what it is set it there and start adjusting the K till u get it to idle.

[s13_silvia_redtop]

im interested in this as well. i have a sr 240 as well and i cant seem to get the stock map to idle correctly at all. if i give it any gas i have to feather it down for like ten seconds to get it to stay alive. i have 740cc deatchwerks, and a z32 maf, that i have callabrated time in time out, any help would be appreciated or if you live in oklahoma and are confortable with nistune let me know

[BlueRB240]

Turn off the 02 feed back and do what PL posted.

[PL]

It depends if you mean it won't return to idle cleanly or if it just won't hold a steady idle once it settles.

If it just won't hold a steady idle then yeah, you'll need to play with K and latency to get the mixtures correct.

If it has trouble returning to idle when you rev it then you may have a reversion problem. This is not uncommon when using Z32 AFM's. Check the following points if this is the problem:

1) AFM placement can be critical - keep it as far from the turbo as possible and make sure plumbing provides a smooth path from AFM to turbo - no sudden bends or changes in dia.

2) Fit a BOV that returns into the plumbing between AFM and turbo. The return fitting should be closer to the turbo and angled towards the turbo.

PL

[s13_silvia_redtop]

Thanks, i think my plumbing and injector latency is off, the plumbing is too short and has a rapid 4 to 3 inch change. i hope this is the problem as its an easy fix. ill keep you posted, and of course im always up for more suggestions.

[PL]

AFM plumbing problems can be quite subtle. I had a car that would hardly run once (S13 SR20DET into a 510 Datsun). These things have very little room in the engine bay, so getting the AFM away from the turbo is not easy. It was overfuelling badly and wouldn't idle at all.

The guy had a friend who had done the same engine conversion, so in an act of desperation he borrowed his friend's AFM plumbing and it ran perfectly!

PL

[s13_silvia_redtop]

well i hope this fixes the problem, here a pic of the plumbing

http://rides.importtuner.com/ride/11890 ... tos/2.html

im assuming this is too close and too fast of a reduction