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Suprise Suprise Megasquirt Edis 8 no spark


PeteMck

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It only fires in 2 banks, not one injector at a time, the fuel just kind of hangs around until the valve opens.

If your using the MS diagram below it should show it's in the right place just pay attention to the direction of rotation. My brain's not working too well tonight so someone might tell me i'm talking rubbish as it's wasted spark but generally you need to be TDC after the inlet valve has opened and closed not the exhaust on cyl 1.

EDIS_system.gif

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I love it when these threads get down to wild mechanical ideas like the cam being in backwards or suchlike.

TSD's suggestion is currently the top one.

There is a simple chain of events:

- Assuming it isn't dead, if the EDIS gets a signal from the VR sensor it WILL fire the coils

- Assuming it isn't dead, if the Megasquirt gets a PIP signal from the EDIS it WILL fire the injectors

If all is wired/plumbed correctly and the timing is somewhere around the ballpark (+/- a barn door) it will fire & run.

A datalog of it trying to start would be quite informative too.

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maybe I have not all understand the thread , but Like FF, the fuel pump solution be worried me

when I have a RRC carbu and 4.6l, I have try to put on a HOTwire system and a external fuell pump HP, ...........never start, to much pressure, and a bad regulator fuel pressure after market,

I think, for the first start, you will must try with a genuine RRC hp pump and a Genuine regulator, this would be the most simple to begin to run good,

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ok, well with regards to the fuel pump, i am not using a rr tank, am using one from a series atm, so obvs the shape and most importantly the depth of the tank is different, hence the aftermarket pump. personally im not convinced by it as wondering if its not maintaining pressure but as mentioned earlier should deliver 180litres/hour at 3bar IN THEORY! Would it be worth replacing the pressure regualtor on the end of the rail incase its faulty?

More aimed at nige this bit, but i didnt get the PMW valve option, could this be part of the issue / not helping? Also dont have an air flow meter wired in. Is it needed and if so where does it go as cant see it on the wiring diagram or am i just being blind?

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no not yet. havnt had the chance to. thts going to be my next move. what makes me think its a fuel issue is that i know all the plugs work and are in the right order and when u first start cranking it trys to catch a couple of times then you just get nothing, so was thinking that maybe its not maintaining fuel pressure.

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Is the fuel pump relay controlled by the ECU as normal?

In the chain of logic, the ECU will run the pump for ~2sec at power-on IF it is set to fire a priming pulse. It will then shut of UNTIL it sees some RPM (I.E. the PIP signal from the EDIS).

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I was beginning to get there too FF, thinking that the FP is posisbly only powered when in ignition live, and not start, hence fuel pressure drops after first couple of cranks and no longer enough to supply fuel to actually start.

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Mines been on MS for a few years and I still haven't got around to wiring my PWM extra air valve :blush: Starts fine you just have to rev it for the first few seconds when it's cold otherwise the idle is too low and it chugs a bit.

I would try the engine with easy start or whatever to check it's good, if it is I would lift the fuel rail and put a cup under each injector. Then as your cranking it you will be able see how much fuel is coming out of each injector and when. If you think the fuel pressure is dropping off and causing it not to run you should be able to see it. Obviously you need to be careful you don't blow yourself up. If you have a pressure gauge one of the manuals available on here tells you what the pressure in the fuel rail should be. I would've thought if you were cranking it and it isn't firing you'd be able to smell the unburnt fuel out the exhaust.

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There are so many things which are NOT CRITICAL for a Rover V8 to chug into life - fuel pressure, timing, idle, in fact most stuff can be anywhere in a very wide range and it will still start & chug along.

As long as the fuel pressure is in the ballpark (30-50psi should be fine), something will get squirted out, and if some fuel gets squirted & ignited it will chug into life. Likewise, timing can be wildly out and it will bang & splutter but probably still start & idle.

One thing to check - is the throttle position sensor wired up & reading correctly? If it's nailed near the top of the range the MS will go into FLOOD CLEAR mode and stop injecting fuel.

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Connect Laptop open Megatune

Go to tools > Calibrate TPS

Ignition on click top box "Get curent"c value should be 20-40 ish

Push throttle to floor, click lower box - value around 250 +/-

If back to front wired wrong

Then right click on any of the guages and select TPS

Value on the dial should be 20 ish +/_

Nige

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