Changing injectors
 

Morning All

Setup
1990 1.6
Reverant build ms2v3 ( awesome, great to talk to, great support )
wideband


Today i decided to swap out my stock injectors for my 440's. Im silly yes i know so i put them in and change req fuel and tried to fire it up. it ran for a little while stupid rich so i shut it off, restarted and im pretty sure ive flooded it. Decided to call it a day. Now ive read up that i need to change the cranking pulsewidth so i have done that with this calc 230/440=.522; .522 x each value for cranking pulse width.

Just wondering if that is all i should need to do atm to get it running? :). Whats the best way to clear a flood with TPS disconnected?


Thanks
Scott

To clear a flooded engine with a disconnected TPS: Go to tools -> Cailbrate TPS sensor and put 0 on the top box (closed throttle), 1 on the bottom (full throttle). Click Accept, TPS gauge should now read 100% or more. Also raise the cranking RPM to 5000rpm, so that in the event that it tries to catch, it still won't fire.

Do remember to put the settings back when you are done.

About to (re)install my RX8 injectors. Strangely enough, the first time I installed them I only changed req_fuel, and didn't notice any cranking issues. So I am interested in the correct areas to adjust...

If you do adjust the cranking PW, do you need to take into account the difference in injector dead time for the 2 injectors?

sounds like all you did is change cranking settings and not the req_fuel.


the only thing that had to be changed was the req_fuel by .522

This.

MSII and MSIII are in %age rather than ultimate PW so you should barely have to touch the cranking settings

As above don't touch the cranking settings (it's not PW, it's %age of the VE table).

From the ms2/Extra manual:
Yup! Got it (for the 2nd time) :giggle:

Sounds like i did it correctly then, i changed req fuel from 12.5 to 6.1 and turned it over. i didnt read about cranking pulse untill i got home. I will try again tomorrow by leaning out the idleing area of the ve table a little and see how i go. it definatly didnt sound right when it was going, i just attributed this to being overly rich.

When the car wasnt running i was almost pegged rich onmy wideband so perhaps something else is at play. Is a rich misfire possible casueing extra fuel to be dumped in the exhaust?

Thanks for the replies
Cheers
Scott

Ok, an update. im a retard. these are the injectors i installed
http://www.ebay.com.au/itm/150654716...84.m1439.l2649

i thought they were direct swap after filing down the tabs but after a re read of the wiki i beleive i need to wire in some resistors. Is a resonable explanation that not wiring these in made the injectors dump duel even though the req fuel was set correctly?.

Is it worth looking into PWM for them or just go with resistors?

Can someone point me in the right direction on what resisters i need to wire in? im assuming i put them inline with pins u2 and v2 yeah?

http://www.miata.net/garage/ECU_Pin-Out.png

Cheers

You can use PWM and use them as low impedance injectors. The wiring used on the MS adapter harness is rated for 11A, and if these are up to 2 Ohms, you should be OK.

Hey thanks :) these are 2.9 ohms. I'm noob at electeonics do these fit the criteria for pwm? in sure if up to if higher or lower when talking resistance
Many thanks

They should be fine. Having said that, I've never used PWM on a MS2, and I've heard that there are electrical noise issues with PWM, so do keep that in mind.

Thanks Reverant for the spoon feeding :).

Im having an issue with getting the car running still. To reduce the chance of my stuff ups with tuning i reloaded the base map and made the following changes

Set req fuel to 6.1 Via teh calulator
And changed the injector settings to
Open time -0.9
Voltage correction - 0.1
PWM current limit - 30
PWM time threshold - 1.2
Per some info i found on the supra 440cc injectors.

and logged a start attempt. (440 start up.msl)
The car started and died immediately.

I did some reading/searching and found that this was likly due to being lean so i added 10 points to the ve table and tried again with the same results. i then read a post suggesting changing the AFR section in the req. fuel calc to 13/1. I tried this and then logged another try (440 start up 13afr.msl)

Its frustrating that my wideband resets during cranking and stops me from knowing what sort of afr its at when starting. power is connected to teh blue power plug behind the popup light that i believe most people use. I might try moving this to the ECU power that Reverant setup for me and see if that provided power while cranking.

The last thing i tried was what the maga manual suggests and upped the ASE settings with same results.

Looking at the logs it looks to me that the map doesnt change enough once the car is running map is too high, is it likly i have a vacuum leak from installing the injectors or do the logs look normal for those with more experience?

The next difference i can see is that in an old log the injector dudy cycle is always above 0 but in the new log it sits on 0 for a while, perhaps the pwm settings im using are incorrect.

Lastly is that the spark angle on an old log at the simular rpm (550) is 16-17 where new log is 5-7.

Thanks for any advice.

Cheers
Scott

Had some success tonight :). Still a way to go though. By setting PWM current limit to 80% i was able to get the car to start and idle.
This seems very high to me as i beleive i fall into this category from the manual "30% on a V3 or V3.57 main board (if you have the active flyback circuit installed)"

I tested the resistance of my injectors tonight from one terminal to another and got 4.6ohms. higher than i expected.
Due to too much signal noise even at idle im gonna go the resistor route. Will the following suit to wire in at the ecu to pins u2 and v2?

http://www.ebay.com/itm/2pcs-10-Ohm-...item2eb55a9e9d

Or does it need to be more like

http://www.ebay.com/itm/5-Ohm-50-Wat...item43a841b110

I know what ones i would need if i was wiring at each injector but it seems easier and neater to do it at the ecu end.

Thanks
Scott

Rechecked with a different multimeter and got 3.6ohms per injector, still higher than the specs i read on the net but oh well.
Acording to the megamanual calculator i should put in one 5.4ohm 25watt resister per injector. Rather than doing this id like to put one per channel at the ecu.
This is where i lose understanding, do i need 2x 5.4ohm 50(or higher)Watt Resistors or 2x 10.8ohm 50watt resistors.

I think im right in saying 2x 5.4ohm 50Watt but would like some confirmation, havent been able to find anything definitive from searching.

Thanks
Scott