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Oh no - a Megasquirt question....


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I am suspecting that my dizzy has play in it which is causing some lumpiness to the engine on low throttle openings.

I have a 3.5, Stromberg carbs and LPG ( closed loop ).

I dont run on petrol atall anymore.

I already have a lambda sensor + TPS on the carbs

If my problem is the dizzy, then i could possibly sort it out by means of a replacement dizzy . . . perhaps. <_<


i could go distributorless. B)

Now, if i went this route, and based it on MS can you tell me if I have the following correct:

I will need:

A crank sensor ( toothed wheel + sensor )

Megasquirt kit + the MS mods for EDIS

a set of coil packs

an EDIS controller jobbie

Is that all I would need? Can I just rig up an empty fuel map and still set all the timing stuff OK?

Then at a later stage, would I be able to use MS to control LPG injectors instead of having petrol injectors?

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Depending what temperature sensors you have already you might need one or two of them - check what MS uses and see if you have suitable inputs already. Not big money anyway.

Either build your own MS with the EDIS mods, or if you're a lazy git like me order it off Bill Shurvington with them already done.

You'll obviously need a few wires, vacuum tubes, connectors and wotnot to hook it all together, and you'll need to sort out brackets to mount the coil packs (two on a V8) and the crank position sensor. Probably new HT leads depending where you site the coil packs.

You'll also need a computer with a serial port (rare these days - if you haven't got one, try to scrounge a really old laptop, else you can still buy serial cards for desktop machines) and a serial cable.

Total cost - less than a new dizzy :)

Of course, I haven't actually managed to install mine yet, I'm always to busy fixing everything else :(

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I am glad you guys are doing the R&D on this. I take it you are trying for two fuel maps & two ignition maps.

Interested to see how you get on Donald, don't forget the dizzy drives the oil pump :o , I have considered dry sump to get away from the age old worn oil pump problem but that is getting a bit complicated.

Have you got injectors for the LPG or are you intending just to control the stepper motor?

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I am glad you guys are doing the R&D on this. I take it you are trying for two fuel maps & two ignition maps....Have you got injectors for the LPG or are you intending just to control the stepper motor?

Sort of - two ignition maps, but MS will only control petrol injection in my case, unless at some point in the future I switch to an injected LPG system (doubt that would be financially viable). I could use the table switching to disable the petrol injectors when on gas, though, which would get rid of a few wires under the bonnet. I'm not sure if MS could control the LPG stepper motor (okay, I am sure - if someone writes the code it can do it, but I don't think anyone has yet), but my LPG ECU seems to be tied into the vapouriser as well so I'm not sure how straightforward it would be.

Interested to see how you get on Donald, don't forget the dizzy drives the oil pump :o

Yep - just take the wires off it and leave it where it is, or very bad things will happen :blink: I believe you can get replacement drive shafts if you want to keep it all pretty (basically the shaft from a dizzy without an actually dizzy on top). Some of them have hall sensors for crank position sensing which offers interesting posibilities with some of the MS code that's in development at the moment (basically, you could lose the EDIS system and have MS decode the hall sensor and directly control either coil packs or even better coil on plug (COP)). Obviously, if you do get one of them make sure that it does drive the oil pump too... If I was doing this to a toy I might have a play with that, but I need Gemima to be reliable (yeah, right... :angry: ) so I'm sticking with a proven solution.

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i dont have LPG injectors, but know where to get them. i would also need to swap the vapouriser for a straight reducer.

its early days yet, but the reality is that the carbs are old and my setup whilst returning a healthy 14 to 15mpg at the moment, it is bugging me about the stuttering on low throttle opening and i dont seem to have higher end performance.

I think first, i'll get a service kit for the vapouriser and see if that makes a difference. If it doesn't then i may look further down the line of upgrading the ignition / gas systems.

Reality is that you'd likely be better off just getting a sequential front end system complete and fitting it, then sorting out the ignition by itself.

oh i dont know!

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It's fascinating stuff once you start reading into it, and there is some serious reading in there.

I'm sure someone has thought about it already but I suppose you could use the dizzy as a crank position sensor for the EDIS itself, though COP sounds like a great idea.

How is the headwork going? (no pun intended)


I think you still need a vapouriser unless you are going to liquid injection, last time I read about liquid injection it was still in the development stage.

Where do you think you can get injectors & vapourisers rather than the whole 9 yards, have a tank mounted already?

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If you're *only* after ignition, go for a MegaJolt (I think full name MegaJoltLite) which is cheaper and contains far fewer components. IIRC it's about £50 built, but it can't be expanded to do fuelling at a later date.

EDIS is currently the best option, but the new V3 MS boards are rapidly heading towards being an all-in-one solution - it's "when" not "if".

Bill Shurvinton is your man, bill (at) shurvinton.fsworld.co.uk

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Wait for it, wait for it. Ah here he is.

Knew you would get here sooner or later Fridge.

How are stocks / delivery times currently with Bill? I am tempted to get a kit to bring back out east with me to stop me falling asleep in front of the tv every night. :rolleyes:

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Everytime i go to the Megasquirt pages , i always feel like i'm diving straight into the middle of the ocean, let alone the deep-end of a pool! :D

Niall, yes the system would have a reducer / vapouriser thing, but not in the same style as the one i have at the moment. Even on the BRC sequential system on my P38, all it is is a plain black box which takes the liquid and converts it to gas. It doesn't seem to have diaphrams that meter the gas in relation to the manifold vacuum at the reduction stage.

Instead, there is a little black box which senses the pressure in the manifold, and the pressure of the gas at the injectors. This ECU then decides how long to open the injectors knowing how much will be pushed through the injector at that pressure.

I'll need to dig out the link, but for the place where you seem to be able to buy the bit in parts, the reducer section is a pipe! You feed the liquid gas in one end and out the other end of the pipe comes the gas in vapour form. Coolant flows over the gas pipe along its length in an outer casing to keep it warm. At the end, you then plug in a pressure regulator for the gas before sending it onto the injectors ( i think the regulator is stepper controlled under direction from the ECU )


So current thoughts are:

1) Try servicing the current vapouriser.

2) Maybe swap the top end to an EFI manifold + plenum ( still using a mixer LPG setup )

3) Megasquirt it for ignition only ( but have full MS for the next stage )

4) Maybe go to sequential gas front end ( which would need to start on petrol - so would need full MS unless i new it were possible to start on gas )

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Yes I did notice all hte sequential setups I have seen have a much smaller vapouriser and as you say they don't have to regulate against the demand since the solenoids are doing that.

I keep calling them injectors but they are not really.

I will be interested to see what they do with the wifes new one when we get it done, I am not touching it I swear :rolleyes:

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I currently have a very nice 3.5 EFI complete engine, and ZF Auto combo, complete with ECU, Plenum, everything, sitting unwanted on my driveway. Very good engine too - removed from donor Rangie the day after it had a fresh MOT. £300 for complete engine incl. all EFI gubbins, £250 for ZF Auto.

Both together - discount!

Ready to go - you'd have it all in by Sat evening!

And yes, all the EFI stuff works fine. And yes, I'll even warrant it!

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I can solder one together and get a replacement

I was intending to get a kit and put it together myself as I have a bit of time on my hands in the evenings here, can't do much setting up as I don't have the Rangie here.

what is the wifes one and who is doing it? and what system?

The wife's one is a Hyundai Coupe 2.0 she is picking up over the weekend, not decided whether we get it done in Kilmarnock or Stirling, don't know yet, probably be sequential.

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