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Mikeys '72 Datsun 240z


mikey

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Oh yes! I finally twigged the Landcruiser.

You were very naughty, "One vehicle green per lane" Mister Sheepers.

I got quite a wee fright when I saw you two coming up behind me in go-fast mode while I was fucking about with the keys.

Loose something-or-other fits, just need to find it.

i had some cutting out issues when i first got the V8 going.turned out the spade connectors (that were supplied with the relay they were plugged into) were hardly touching the terminals on the relay. every time it got a bit of vibration it would cut out.turning the car off and back on again would usually make it contact again.anywho, yes you did have to turn it off and back on.guy behind you was taking photos and nearly hit you.
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I like that you can climb into the engine bay, between the radiator and engine. Must be super handy for working on the engine. Handle bettererer?

Ha, it sometimes does come in handy. I can't really comment on the handling thing much since I've not really been able to thrash it yet. boooo

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Regarding the engine stuttering, I would not be surprised if it was something to do with the air flow meter.

Hot wire airflow meters are notorious for pooing their pants when they are not in the standard airbox/housing.

It's really critical to get the signal right, because the airflow meter reading dictates what the fuel, spark AND cam timing end up doing.

Symptoms are usually that top rpms and open throttle position everything's awesome, low throttle low rpm and it stutters etc because air/fuel/cams are all having a nightmare.

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I would not be surprised if it was something to do with the air flow meter.




This, is a good idea. I will look into this more. I wouldn't be surprised if I actually have a few things causing slightly different stutters.

There used to be some hesitation you could break thru eventually. Now there's what feels like a complete shut off when flooring.

BUT. I have learnt some things. When it cuts off the ECU is still running and according to the timing light, still sparking. (This is not conclusive, it might still be sending spark signal but not the enable signal to the coil drivers)

ALSO I took a video of my fuel pressure when it happens:

th_VID_20121206_202017.jpg

My top suspicion is that the fuel pump power wire is shorting against the inside of the tank.

Other possibilities are my baffle is not letting enough fuel in for the pump to pressurise under load.

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Other possibilities are my baffle is not letting enough fuel in for the pump to pressurise under load.

I was thinking about this last night and was going to mention this this morning. drill that lil hole out in the pink baffle thing you mentioned awhile back.

EDIT:

Symptoms are usually that top rpms and open throttle position everything's awesome,

except he said its dying when he floors it?

also if the fuel pump is being strangled in its little baffle unit it could explain the relay getting hot as the current to the fuel pump is increasing to try and get more fuel to the engine?

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that shit aint right!!!

looks really linear with revs - like its super consistent with throttle, revs and possibly vacuum?

is the fuel rail pressure regulated with a vacuum type diaphragm?

have you got the supply end and the return end of the fuel circuit around the wrong way?? i don't even know how the fuel supply works on your motor, maybe it doesn't even have a return? i remember looking at it when i saw your car but i cant remember how the fuel circuit works.

what i was thinking is if the fuel circuit is working backwards somehow then the bypass is opening right up when the vacuum drops and the pressure drops. if it still has heaps of flow but no pressure then maybe that's what it is?

if it has a return you could pull the hose off and stick it in a bucket. if the fuel volume stays kind of the same when its cutting out then maybe its the pressure regulation rather than starvation?

yea, typing while thinking will result in a wall of unintelligible text but it might be useful....

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Regarding the engine stuttering, I would not be surprised if it was something to do with the air flow meter.

Hot wire airflow meters are notorious for pooing their pants when they are not in the standard airbox/housing.

It's really critical to get the signal right, because the airflow meter reading dictates what the fuel, spark AND cam timing end up doing.

Symptoms are usually that top rpms and open throttle position everything's awesome, low throttle low rpm and it stutters etc because air/fuel/cams are all having a nightmare.

i second the afm, or the tps... my 2c's

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Mikey - can you do an MS paint of how your fuel return system works? I seem to recall that it loops around in an unconventional way and this might be the cause of your issues.

I'm on the same page as Sheepers on this one - pretty sure the regulator is getting confused. I remember that the ECU was logging lean-out faults when you let me drive it in Hahei, which will be making the computer get a fright and might cause it to turn shit off.

Have you tried adding a vacuum line to the regulator?

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Ok. All of your ideas are super awesomeness.

I'm gonna tidy up the in tank wiring and maybe make some holes in my baffle to rule that out.

My fuel setup is unconventional. It's dead head which is how the stock 350z setup is. But not a common way to go. Could be this. Harder to fix though.

I've not hooked up vacuum line to reg yet. Didn't think it would cause this since not even managing static pressure.

I report back soon. With many drawings of emu.

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