MegaSquirt EFI install

[spandit]

Just started work on installing EFI to my 710K, so don't try and talk me out of it

Planning on replacing the carbs with something like this (which will need to be 3D printed - if this isn't economical/advisable, I've got a simpler design that I can manufacture myself):





I'll be fabricating two short fuel rails, to be joined with high pressure hose (because the carbs are set at different heights). This will allow me to use the stock intakes and air plenum.

I've bought a 12V Bosch fuel pump and am planning on getting that running through a fuel pressure regulator onto the carbs. Once I get the EFI actually installed, I can up the pressure suitable for injection. Pump and injectors came from a BMW E28 - got 6 injectors, connectors, fuel rail (which I'll be scrapping/selling), throttle body, idle control valve, throttle position sensor plug a couple of relays for £50.

MegaSquirt (actually MicroSquirt) ECU is coming from the USA. Comes with a free O2 sensor but I'll have to work out where to put it - might be welding two bungs into the exhaust and swapping it around (might need a wideband for initial tuning).

Ignition will be using the Ford EDIS system that is already up and running from the 36-1 trigger wheel mounted on the crank pulley.

Fun times ahead!

[Haf-e]

Looks like a nice design for a part - but I don't understand where the throttle body will go?

I am working on doing EFI as well with a microsquirt - but I have a fuel injection setup from one of the redbull trucks to use so I already have the plenum / injectors / throttle body worked out for me.

I would be interested in discussing some details offline if you are interested... let me know.

Christopher

[spandit]

Throttle body will be going in between the air plenum & the filter assembly (if there is space). It's a BMW unit. Will PM you as glad to not be doing this alone!

[spandit]

Have refined the design a bit to make it simpler to manufacture as 3D printing is a no-go. This has the injectors pointing down at 45º towards the middle of the inlet ports

[spandit]

FPR (fuel pressure regulator) arrived today. Hoping to drop the gas (petrol) tank later today, to install a return line. Have to work out if it's possible to use this regulator to lower the pressure of the Bosch fuel pump to use with the existing carbs, so I can run the vehicle before the rest of the EFI is installed

[spandit]

Well, looking good. Have dropped the tank and rigged up the new 12V Bosch fuel pump (0 580 464 032) with an inline pre-filter. Attached it all up to the regulator with the outlet leading into a fuel can (because I haven't drained the tank yet!). Managed to turn it down to around 3.5psi so should be fine to run the existing carbs through as an interim measure.



Need to fit a return into the fuel tank - two of these came with the regulator and thinking of bolting to the fuel tank but unsure of clearance:

[spandit]

Well, jerry rigged it up this afternoon (fitted a return to the tank and mounted the regulator on the bulkhead). Used seamless stainless hydraulic pipe for the return line which is way overkill but I had some lying about that I'd bought from a scrap dealer a while ago (funnily enough to replace fuel lines on a BMW 5-series)



The hole for the return line isn't sealed - for those that have taken the fuel pickup out in the first place, you should know why - the pickup is angled (and goes into a tube) so putting two lines into the tank at once is pretty difficult



Tee'd off the fuel connectors to the carbs to give me my return path via the regulator.

Plugged the fuel pump into a 12V leisure battery and switched it on. Was surprised to find no major leaks of fuel as was using a random collection of various fuel hoses and connectors to get to the required length. Although I got it running initially, it became fairly clear that despite the regulator being turned down as far as it would go, there was still too much pressure and the forward carb was dripping fuel (float valve overwhelmed as Jim said it would in a previous thread).

As proof of concept, however, it works and when I get the higher pressure EFI stuff installed, it should do the job nicely (although hanging the fuel pump from the front splash guard with a cable tie probably isn't the most secure location... )

Nice to hear the engine running again, albeit briefly...

[spandit]

Have simplified the design somewhat to make it easier to construct (although will need to buy my friend with the TIG welder a lot of biscuits...)

[kpoling]

Nice work Robin! Do you do 3D CAD/modeling for a living?

[spandit]

Nice work Robin! Do you do 3D CAD/modeling for a living?

Thanks! No, it's just a hobby (made these using BRL-CAD which, although quite powerful, is a bugger to use - it is free, though, which is what appeals to me). I suppose if someone wanted to pay me a few $$ for some 3D work then I'd see what I could do

It's a good way of thinking through how one is going to design these things - the manufacture of said items is another factor - I've only got a small lathe and no milling machine so having to be creative with how I'm going to make these bits...

[spandit]

<iframe width="420" height="315" src="http://www.youtube.com/embed/INnDUIFYHQw" frameborder="0" allowfullscreen></iframe>

[McCall Pinz]

Keep it up. I'm not sure I'll ever be able to do something like this, but its fun to follow along.

[spandit]

That makes two of us!! Still wondering how I'm going to manufacture the dummy carbs - main problem is I've now changed the design again but it means drilling an angled hole through an angled face (both at 45 degrees). I've calculated the dimensions of the entry and exit holes, but actually getting them lined up is going to be a hassle (and that's before I try to make them!). Am planning on cutting them by hand and hoping the TIG welding my friend has promised to do can fill the gaps...

Just got some fuel hose delivered today - it's really hot (for the UK at least) and I don't really feel like working outside in the sunshine just yet. Sat inside on a laptop with the EFI controller and a few sensors hooked up to it, just to see if they work (which I think they do). Might brave the weather and properly install the EFI pump as it's currently hanging from a bolt hole with a couple of cable ties!

Have asked a friend to order me some thermistors to use as CHT sensors (each one costs about £2.50 whereas to buy a complete sensor is about £16 and I'm told it won't fit under the spark plugs anyway without breaking)

[spandit]

Some minor progress today. Fitted the fuel pump and filter securely and installed decent quality fuel lines, including proper double banjo fittings on the carbs - didn't get any fuel leaks this time and actually got it running for a bit before it stalled and started exploding out of the exhaust again

Decided to stop before the neighbours called the police (seriously sounded like a gun going off!). Tomorrow I'm hoping to wire in the new ECU (to replace the MJLJ) although think cleaning the plugs will be the first job...

[spandit]

Well, finally got it going "properly" today (i.e. wasn't banging away*) and actually idled to a degree (long enough for me to take a short video):

http://youtu.be/tOAK3mCBlNQ

It's developed quite an oil leak from the #4 cylinder, which I think is the oil seal in the return tube, but not sure. It started smoking me out, though so I had to shut it down - I'm sure after a few runs the excess will have burnt off and it won't be such a problem but I think the cylinder is going to have to come out again...

* as much