Fuel enrichment of AFM or MAP sensor - JA type setup - how??

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enthuzed
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Fuel enrichment of AFM or MAP sensor - JA type setup - how??

Post by enthuzed »

My GSR-3 (almost same as JA) has been running very lean & resulting in me rarely driving it. It's lean at idle as well as right through the rev range. I know it richens up slightly when backing off too. But still too lean then as well...

I've had the injectors cleaned & tested & checked ECU pinouts & voltages/resistance of all potential suspects:
Injector resistors
TPS
Variable resistor (idle control)
Other stuff I cant remember

When I disconnect the AFM whilst running at around 3000rpm the engine is sposed to falter then return to normal. In my case it just dies.
I trial blocked the single bypass hole in the AFM unit ( JA's have two) as per Alspos' suggestion but it was really doughy and ran like crap.
I cant remember but either the voltage or resistance didn't change for the AFM.
Swapped in another airbox with its AFM and then four other AFMs directly without the airbox, all with the twin bypass holes. The vehicle would not start with any of them!

I've modded the airbox so it now takes in 3 times the cross section area of air. Its not the core issue as it was running lean before that too, in fact the whole time I've owned it, which is 5 years. It lead to an engine rebuild already before learning of its lean running.

I would like to richen the fuel mix, has anyone modded their AFM or MAP sensor to do it? And changing the resistor on the side of the AFM will yield what sort of result?
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thrash
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Post by thrash »

have you replaced the fuel filters etc?
The line might be clogged?
Voltage at the fuel pump?
quest wrote:
WANTSOM wrote:Personally, I find sloppy boxes very unsatisfying. I like them tight and taught to the point that if you dont have to push to get it in then its probably too old and time to get a new one :P
don't try explaining that to her tho..... just leave. lol
Komeuppance
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Post by Komeuppance »

Yes, check the fuel supply.

Have you checked the coolant temperature sensor resistance?? A bad one could be sending the wrong signal to the ECU. BTW, leaving the CTS unplugged will tell the car the engine is ice cold and the ECU will richen up the mixture, band aid way to do it though.

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thrash
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Post by thrash »

fpr might be another possibility
quest wrote:
WANTSOM wrote:Personally, I find sloppy boxes very unsatisfying. I like them tight and taught to the point that if you dont have to push to get it in then its probably too old and time to get a new one :P
don't try explaining that to her tho..... just leave. lol
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panda
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Post by panda »

I'd be checking the fuel pressure arriving at the inlet manifold/injectors. It should be around the 40-50psi mark I believe. Anything less than that, could be clogged pick up in the tank, the fuel pump itself, clogged lines & filters, or the fuel pressure regulator on the return line. Also check that the pick up hose between the tank & the pump isn't cracked & sucking air.
The issue sounds more mechanical than electrical, as most electrical issues make it run rich.
Good luck.
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