Problems after changing injectors

[iceblade]

ive got a type 1 board in a ca18det, been running a generic stage 3 map for a while now and ive now fitted denso 720 injectors and im having major problems getting the fueling correct,
i set the injectors using the the resize injectors function but unchecked the change load scalers box

the injector multiplier is now 295 and latency according to some info i found is 650 (the 444s i had in there were 405 and 640 respectively)
i then set the fuel map to all zeros to check the fueling was accurate and it was off so i set the rpm around 3k and set the multiplier to get the afr to 14.7, then i dropped the revs back to idle and it was running at afr 10.72 so i dropped the latency to get 14.7, then checked the 3k area again and it was at 17.xx so i tried a few times more and the same every time.......
can someone point me in the right direction to get this right...... it seems like im doing it backwards or something......
pleeeeeeease......

[Fordy]

did a quick resize on a stock file s13_CA18DET_39f05_edm_MT

stock injector size 370 with a injection multi of - 183

resized from 370 to 720 injection multi now - 94

[iceblade]

ok now im even more confused

[Bernardd]

Was the old tune for z32 maf or something along those lines? Fordy gave you specs for a stock maf / 720cc setup.

[skyline_stu]

720's are rather LARGE injectors !!. Especially denso with their slow response (and their assocated latency).

What resistance are they??

dropping resistor installed at all ???


Stu

PS. sometimes you need to juggle both constants - but latency has an effect everywhere.. Do you have your o2 sensor physically unplugged when trying - it may be creating troubles if connected...

[Fordy]

Was the old tune for z32 maf or something along those lines? Fordy gave you specs for a stock maf / 720cc setup.

very good piont there, i think stage 3 needs a z32 so should be injectors, maf then around 247?

[iceblade]

dropping resistor is being used being a ca18det, and have a pre-facelift ecu with no lamda control.... so far ive settled for 345 multiplier and latency of 650 giving the main map area a normalish afr but a stupidly rich idle or 12ish, a mate of mine saw a tune of a ca with 720s and the latency was up around 1000!!!! ive even tried that but then the multiplier to set the idle correct made the rest of the map go to the 17's
the ca runs a base fuel pressure of 2bar, would that be causing me any issues?? i.e. not enough pressure for the larger injectors?? (or something similar???)
oh and its the standard ca18det dropping resistor and using a z32 maf

[skyline_stu]

have a pre-facelift ecu with no lamda control....

That's an interesting comment. Your fuel table has numbers start at 0 when viewed with the 'raw table view'?? Correct?? because your comment of 'main map area' confuses me - Mixture feedback, if being used (values over 128) could be screwing things up. Base Image ID from your car is what (from the ECU casing)

You still haven't answered the question posed earlier.
What resistance are the injectors (measured with a meter).??
Are they a 'genuine' injector or a high flowed set (ie drilled out tips or removed end plate)??
Injectors New/old/reco'd ?
Is fitting the injectors the only change performed - or did you add on extra stuff

And yes, 2bar (30psi) seems a little low, your pressure should be 2.5bar at idle, no vacuum hose connected.
Your using a decent pressure guage, I've seen a hell of a lot of the small (1" or so) guages being very inaccurate and WAY off. Remember the tools needed to calibrate your car must be accurate and repeatable. Is your regulator an Ebay special (not a riveted together SARD by any chance ??) ?

The latency seems too low for most general BIG Denso injectors... When adding in a new MAF/injectors with older style ecu's , you'll have to recalibrate the WHOLE fuel table again - including all the scales, constants, VQ values.

I can be tricky to diagnose faults over Email - Think of this, would you go and see your Doctor when your sick, or ring him and explain you symptoms and ask for a diagnosis. You might forget to mention a little bit of info - see where this is going - now you've now told me you have a pre facelift ecu, no lambda, fuel pressure is at 30psi, etc!!..Tuning is something that takes quite a lot of time to learn to understand what your seeing.. and why your seeing it..

Stu

[martinbattye]

for calibrating new injectors.

set the injection multiplier so that you achieve correct AFR at full load..

then alter lag time to achieve low speed AFR..

youll mostly find that the published figures for this will not match up with what youve got on your screen.. but so long as your fuelling is A-OK then its not an issue.