Hi yall

Got a problem with my car and thought id run it past you guys and see what you come up with.

The car is a 1999 ( australian 1998 ) nb8a
I has the avo turbo kit installed with the adaptronic plug n play
Using rx8 440cc injectors
Its been installed now for 2 months and was professionally tuned. By a local mx5 specialist here in sydney.

The car has always been a pig to cold start ever since i got it back from the tuners. I assumed this was due to fouling plugs. It was burning a bit of oil and running rich. Basically putting new plugs in once a week or so solved this temporarily. Once warm it wasnt a problem starting it.

Until last week. Sunday i was driving it around and it was running fine, brought it home and garaged it over night. Next morning it wouldnt start even with new plugs.

Ive increased the cranking fuel with out success and tried dwell settings between 2100 and 5000 with out change, tried spraying start ya bastard into the inlet and it fires until it burns it up. After multiple attempts at starting the plugs arent wet and dont smell like fuel.

In the gauges window of the adaptronic i get a - next to pump, not sure if there should be a read out there or not on an mx5 / miata

Any ideas or suggestions would be greatly appreciated

Cheers for the help

Paul

 

Upload your map.

 

Take the fuel line loose somewhere (possibly at the filter) and run the line into a bucket or jug (you might put a longer piece of hose on the line to make it easier). Then try to crank it for a moment. If huge amounts of fuel don't go into the jug then your fuel pump is bad.

 

heres the .ecu file.

ill give the fuel line check a go tonight

thanks

Paul

 

At the corrections tab/air temp correction, why do you hvae -128? Unless there's a specific reason that's wrong.

Why is there values for aux 12/13? they dont hurt anything but what are they for? Adaptronic shouldnt have anything connected to them.

Thats all i can see that looks suspicious. I dont know why i cant look at the triggering though. Weird.

Oh and one last thing the dwell time for the standard 99 coils is 4-4.5us.

 

to be honest im not sure. tripple88a. thanks for the response tho.

ive forwarded your post on to Andy from Adaptronic ( one of the bonus's of living in sydney is that hes pretty familiar with my car and is also trying to trouble shoot this for me) and ill let you know his response

there was a few issues with it previously during the setup so they may have rewired something onto aux12/13 from somewhere else

the air temp correction does seem odd as well. so ill see what he thinks.

thanks again ill let you know how it goes and if you have any other ideas, id be very greatful

cheers, hope your enjoying your weekend

Paul

 

from andys email.
"Aux 9-16 are logic only outputs - 12/13 aren't being used for anything"

"Yes, that in the air temp correction will be a problem, if you're actually at that temperature. But if you're not, that won't cause a problem."

so still hunting. honestly im starting to think it might be just a badly timed old school mechanical failure. fuel pump, blocked fuel filter, etc etc ill look into it further in the morning

 

heres a log of trying to start it today.

ran the injector test today and i can here the injectors clicking.

also i can here the relay for the fuel pump clicking on and off by inverting the aux 5 for fuel pump ( now that ive found out where to do it ).

still no joy however, car cranks but doesnt fire

 

Man 18ms on 450cc injectors is a lot.

Copy my cranking values here and try again. Did you check spark btw?

https://www.miataturbo.net/adaptroni...install-60355/

 

Fuel pump not pumping, I assume.

 

It is starting to look like the fuel pump.

Tried removing the parcel shelf carpet and listening for it. Nothing.

Tried listening at the fuel cap with a mate turning the ignition on. Nothing.

D.c the adaptronic and plugs standard ecu in. No change cranks but doesnt fire.

Going to check the power to the pump but yeah im guessing it is the pump at this point

Paul

 

Swapped outthe fuel pump and filter yesterday afternoon.

Car works as it should now. Including a pretty boss cranking fuel map that andy from adaptronic sent me left the car out last night it gets down to about 5 degrees celcius where i am

The car cranks and fires now at 0%tps after about 2 seconds

Cheers for the help guys id say fuel pumps definately solved the problem.

Paul

 

Could you upload the map that andy sent you please? Would like to see the cranking values.

 

yeah no problem ill try and get them up in the next day or so

 

Paul you still around?

 

sorry for the delay

car is fixed now and ive been out enjoying it for the last few months.

turns out that the non starting issue was caused by a dead / dying fuel pump or blocked fuel filter ( i changed out both at the same time )

so good news is $50 mainy brain cells and an all mighty fuel vapour induced headache later. and the car is now sorted and touch wood reliable again.

ive included the .ecu from my adaptronic it was dyno tuned at mx5 mania in sydney but due to having no boost controller it only goes to 5psi currently so it wouldnt be tuned above that.

cranking fuel settings are from andy from adaptronic. again id like to mention the amazing level of customer service i received from him

these fuel settings might need a little bit of tinkering in the cold start region as on cold mornings the car will cough and stutter immediatatley on start unless its reved for a blip or two. im guessing that if the fuel was brought down a touch in the 15degree to 30 degree area it would probably solve this however it hasnt caused me enough concern or problems to go in and try it out.

anyway thanks for your help every one im pretty damn happy to be boosting reliably these days

 

Hi Paul,

Did you measure the dead times of those injectors yourself?

I came up with this interpolated from the RX-8 ECU info:



I'm not saying if it is right or wrong!

If you increase the dwell time, does the car become easier to start?

Cheers