megasquirt, thoughts and questions Options

[metalmorphosis]

MY CAR’S HISTORY AND THOUGHTS AND QUESTIONS ABOUT MEGASQUIRT

My car is a 1973 1.7 with stock fuel injection that I bought in 2002 and used to drive quite often and for 3-4 years it was my only ride. It was around 2012 that I took it off the road for rust repair and after 2 years on jack stands and a lot of new metal, I got it back together, running and on the ground. I still have a lot to do to make my car nice, but for now the goal is just to have a driver. In the last 2 years I've only driven it briefly (and close to the house) every few weeks due to it running like crap. It won’t idle when cold and spits and sputters while driving but will usually improve after it’s been driven for about 10 mins. I feel like my issue exists in the fuel side and not the ignition. I plan to do a megasquirt conversion in phases due to limited time and I don’t want to drop the motor now. I’m sure some would say why not try and get the original fuel system working properly again and my main answer would be my desire to add boost to this motor in a later phase of this project. That being said, I regret not buying that complete, running 1.7 motor with all its fuel injection components that was in the classifieds a few weeks ago. I assume I could have switched whatever fuel components onto my car and probably be back running again without all this conversion I’m facing doing.

I want to do something like Mcmark did with his megasquirt conversion, which is not modifying my stock 1.7 and eventually adding a small turbo for some extra fun. The first phase would be fuel only due to not having time to drop the motor to do crank fired ignition. The second would be ignition and boost which means motors coming out to install the toothed wheel and sensor and using a small new turbo or a used one from a vw or volvo and I assume some type of intercooler. Luckily, I'm a metalworker and owner of a metal shop so all the metal fab needs that will crop up with a turbo install are no problem. Unfortunately, as a father/husband, a small business owner, a full-time employee at my day job, and the owner of 2 classic cars I have very little time and car projects have had to sit mostly untouched for the past few years. But I’m going to try and carve out some time to get my 914 running reliably again, without tearing it too far down.

THE WAY I THINK I WILL ACCOMPLISH PHASE 1

I plan to purchase the components needed from the dubshop as it seems they have quality parts, and everything needed in 1 place. I would like to retain the stock throttle body and intake. I assume I could remove the original TPS from the throttle body and install a new universal bosch TPS somehow in its place. I also hope to be able to mount new injectors in the stock intake. I'll have to wait until I have the injectors in my hands to know if the diameters of the injector will work with the bore in the intake and if the clamps will hold them in place. If modifications are needed, I’m fairly confident I’ll be able to come up with a way to make whatever changes are required. I believe I’ll be using the Walbro high flow fuel pump but I’m not sure if I’ll need a new relay board that the dubshop sells, although I assume so cause of the new fuel pump. Other than the various sensors required I think that’s it for phase 1 fuel only. Ignition and boost will have to wait unless there’s a way to do ignition without dropping the engine. The final concern I can think of now is tuning, but it seems like with the tuner studio software, this forum, and the dubshop I can get it dialed in.

Parts I think I’ll need for phase 1

1- Megasquirt 2 V3
2- Walbro fuel pump
3- Fuel pressure regulator
4- Fuel filter
5- EV1 fuel injectors
6- Modified coolant temp sensor
7- Intake air temp sensor
8- GM MAP sensor
9- O2 sensor
10- Various weld on bungs for sensors
11- Wiring harness

Questions

1- Does anyone here have any experience with the dubshops products/support?
2- Megasquirt 2 V3(through mount components) or V3.57(surface mount)?
3- Has anyone here tried to mount a modern universal Bosch TPS on original 1.7 throttle body?
4- Will EV1 injectors fit stock intake w/o mods?
5- Do I need a new relay board that the dubshop sells or will the stock 1 work? I assume with the new fuel pump I’d need the new relay board.
6- Walbro fuel pump?
7- Mounting position of modified coolant temp sensor (I assume under #3 cylinder somewhere in air stream)?
8- Mounting position of intake air temp sensor? Does it need to be before or after the throttle body?
9- Mounting position of O2 sensor? I want to keep my heat exchangers and I’m running a Bursch muffler, so I assume it’d be in the muffler tubes where all tubes are merged into 1 tube.
10- Tuning? I don’t even know what to ask here yet, but it worries me.
11- Anything I’m missing for fuel only? And should I be able to expect good results with only doing fuel for now?

Thanks in advance for any advice y’all may have I’ll do my best to keep this thread updated, but like we’ve already established it takes me forever to accomplish car goals. So here’s to getting another 914 back on the road reliably. The flip side of the coin on all this is if I can’t get the 914 running reliably in the next 6-9 months selling it and using the money to get my vw notchback on the road is an option I’m considering. My son is 12 and I don’t have forever to get a classic on the road to enjoy with the family. The Porsche is, of course, only a 2-seater and I have a family of 3. It sucks to think of selling my 914, I have always wanted one since I was a kid in the 80’s. I have been fortunate to own 2 of my favorite cars for a long time now, but sitting in the garage not running reliable makes my wife real happy while having to park her new Jetta outside. For now this isn’t about whether or not I should sell my 914, but I’m not getting any younger either.