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PROBLEMS WITH MEGASQUIRT


des90

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I have a 4.6 engine with the intermediate front cover with a dissy and carb.Decided to go injection to help with extreme vehicle angles off road.After looking around picked megasquirt as it seemed to have good reports.The ms2 and loom was supplied by phil at extraefi who loaded all the specs on to the unit.I used the injection hardware from the 1995 to 1998 4.6 range rover with the rv8 idle valve,tps, coolant and air temp sensors.The ms2 has a map sensor built in.

After everything has been fitted -checked and double checked the engine will not fire!!

The ignition has not been touched since it ran well on the carb-all i have done is put the injection unit on

Anyone any idea,s cos iv been on it a week and am slowly going mad

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Just like any other problem you need to work through the basics.

When you are cranking the engine are you getting an RPM reading in Megatune ?

Are you getting any spark at all ?

Are you getting fuel ?

Fix/check each of those potential problems in turn and you'll be most of the way to getting it running. Unfortunately this forum does suffer from a "there be dragons here" attitude towards MS installations that don't use EDIS and MS1 but there's no reason why your setup shouldn't run, it's probably just a minor wiring problem. If you can answer the 3 questions above it'll give more clues and help narrow down where the problem is.

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Oh... talk about making life complicated for yourself  :rolleyes:

Ditch the dizzy, slap an EDIS8 and a couple of coil packs in there and at least you will know you have a spark...

Then as above, check that MT is showing stuff as it should.

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Um, surely if you're running direct coil drive you can't use the dizzy as spark input, you need a trigger wheel of some sort indexed to the crank.

But I'm with the others - Check the basics (do you have sane readings for RPM, MAP, and IAT/CLT, is the timing right for your trigger wheel?)

If you can, post a screenshot of MegaTune/TS or a datalog of cranking & trying to start. It may help.

Oh and maybe mods could move this to the MS sub-forum ;)

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Um, surely if you're running direct coil drive you can't use the dizzy as spark input, you need a trigger wheel of some sort indexed to the crank.

How exactly is this configured? Are you driving the original ignition coil (and using the distributing bit of the dizzy) or coil packs? If the latter then you'll need to switch to a trigger wheel of some sort on the crank, or MS won't know which coil pack to fire.

There's no reason why direct coil drive shouldn't work...but you are making life hard for yourself!

Edit: If you have no joy, I'm driving past you on 31st Oct. I might be persuaded to stop by and take a look in return for a mug of tea and maybe a biscuit :rolleyes:

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Hi all- it appears to be set up ok- have rpm reading and in fact all the readings-done wiring check-several times.Trigger signal comes from neg terminal on coil and yes i have a good spark and fuel. There is a boost pack on the ignition from rpi and the timing hasnt been changed. My next move is to stop the fuelling and give it a spray of ether to see if it fires on that!!!

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<I have some knowledge here of Des and his problem :D ,>

He hasn't mentioned he is on 'Direct Coil Drivers', (and using Dizzy for spark input ! )

My advice was go EDIS 8 and dump dizzy and DCDs :)

Anyone care to add ?

Nige

where is this direct coil driver setting in ms2??

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Just like any other problem you need to work through the basics.

When you are cranking the engine are you getting an RPM reading in Megatune ?

Are you getting any spark at all ?

Are you getting fuel ?

Fix/check each of those potential problems in turn and you'll be most of the way to getting it running. Unfortunately this forum does suffer from a "there be dragons here" attitude towards MS installations that don't use EDIS and MS1 but there's no reason why your setup shouldn't run, it's probably just a minor wiring problem. If you can answer the 3 questions above it'll give more clues and help narrow down where the problem is.

Yes i am getting an RPM reading in Megatune and a good spark when cranking.After cranking the plugs are wet-it did fire once and ran as tho it was badly retarded-and we have checked the timing which hasnt changed

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Am I right in thinking this is a fuel only Megasquirt installation ?

Have you tried starting it in "flood clear" mode ? (Throttle to the floor and hold it there while you crank) If it starts in this mode (the MegaSquirt reduces the fuelling substantially in this mode) it would suggest overfuelling either as a result of a bad fuelling map/required fuel setting or a problem with the fuel pressure.

How confident are you that the fuel system is correctly configured ?

If the return pipe from the fuel rail isn't clear you'll get massive overfuelling.

Can you post your .msq file and a data log from when you are cranking it ? Not sure what file formats this forum accepts but hopefully it will let you post those.

In particular I'd be interested in knowing the coolant temperature and the injector pulse width whilst cranking.

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The MS is set up for fuel only with the trigger signal from the neg terminal on coil.The Req fuel setting was calculated in megatune - 20.20 /10.10 .From memory the injector pulse reading when cranking was 7.24.Air and coolant readings were correct and the tps was correct.MAP reading was 101 changing to 98 when cranking.I dont know where Nig has got that it has been set up for direct coil drivers thats unless I have had total brain fade and missed it in set up

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One thing I have noticed that, compared to earlier range rover injection systems, this 4.6 unit has a diaphram unit on the inlet of the fuel rail.There doesnt seem to be a problem with the return pipe and the fuel pressure is constant at 39psi-I have an adjustable fuel reg on it.

Just to give everbody an idea where i'm at- i'm an engineer at heart-NOT a computer whizz -I'm surprised there's not a stage by stage set up list

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IT RUNS!!!!!! - Faulty relay on fuel pump supply -failing under load -it has now been stamped on and thrown into the sea !!!!

I presume the rising and falling idle speed is due to it needing tuning?? So all you guys- where do i start-or do i just let tuning studio do it?

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