another EFI/ITB thread, need some help piecing it together

[shamrok]

Finally decided to stop futzing with CIS on my '83 SC and go to EFI (fuel only, for now). I've been pretty attracted to the Bitz EFI for a while, but on a whim I ordered the Triumph ITB setup from CCM. After doing lots of reading, I think I just want to go straight to Microsquirt from the start, but need a little urging from the experts here.

So along with the ITBs, here's what I've come up with that I'm looking to order:
-Microsquirt w/ harness
-Summit fuel pressure regulator
-14point7 wideband O2 controller w/ sensor
-GM MAP sensor
-IAT sensor
-Engine temp sensor
-TPS connector
-Fuel lines from filter to FPR, and another between the rails
-Injectors? I found some refurbed Denso 4390 injectors from a Nissan that have the right specs, unsure if they will physically fit tho
-Injector connectors
-MSD Streetfire/coil/wires/rotor

Anything else I'm forgetting?

I admit I'm not super electrical savvy, and this is where I think I need the most help. I have a pretty good idea on how to wire the injectors and sensors to the MS, but having a hard time visualizing how to tie it all into the car, especially the existing relays (reverse fuel pump logic? need to add a 'main' relay as well? yikes). I guess I just need the nudge to go forward, or should I just go with the Bitz? Budget is a concern, or I'd just order the sweet sweet kit from Rasant.

[wreckah]

i did the same thing (81 SC) , and i did it in steps:
- first bitz kit, to get the fuel rails, etc...and start with fuel.
- then EDIS and microsquirt upgrade, so now i control ignition as well.
- itb's coming in the near future.

the microsquirt will fir nicely under your passenger seat, where the lambda brain of your car currently resides. You can take out the whole brain + wiring loom through the hole in the rear firewall, just above the gearlink cover, and you can use that hole to push the MS wiring loom through. (you can also feed your wideband loom through there) I also deleted the full 12 pin ( ? ) engine connector just next to the rear suspension point. This does away with all the wiring for CIS: FV, O2 sensor, etc...god knows what else they connected through that connector.

As far as relays go:

- engine: i added one main power line, (added a live wire from rear fuse block, thick one) through a standard relay, which is controlled by one of the switched feeds from the rear fuse panel. This feeds power to injectors, wideband controller, Microsquirt, and in my case also the EDIS unit.
- front trunk: you can probably resuse the stock FP relay, but i chose to put a new, standard square relay in. This is fed by the stock FP feed, and controlled by the microsquirt: the microsquirt has one wire which needs to go to the front, which goes to the relay. It grounds the relay, giving power to the FP. the MS controls everything else: 2 seconds power up, switch off when engine not running etc...it is basically completely stock relay behavior. You can get rid of the SC rev-limit wire, and pink ( ? ) control wire from the fuel distributor.
Plenty of holes to get a wire from MS to the front.

Wiring it all up is quite easy, just follow the MS manual closely. Pay attention to grounds. It's easy but it takes time. The wiring diagram in the Microsquirt manual is super clear.

I went a step further and did ignition as well, with EDIS, and the car started first key...and i'm not a wrenching hero by any means.

good luck,

[shamrok]

Awesome, exactly the kind of thing I was looking for. I really appreciate the physical descriptions of where you placed things. The more I scour the wiring diagram, the more it makes sense. I think I’m gonna draw out a plan for wiring and see if anything doesn’t make sense. I’m tempted to do EDIS right off the bat, but I want to do it incrementally so I can troubleshoot single components along the way.

Thanks again for taking the time, I’m sure I’ll have more questions. Any sensors I’m forgetting or missing out on? One thing that's unclear is do I need the AAR? Or can I delete that and replace its function in software?

[wreckah]

hi shamrock,

forgot to say: the 'power' relay in the engine bay feeds a little fusebox which distributes the power for all the components...EDIS, MS, Wideband, injecotrs, etc...

incremental is good, i know i would not dare to do it all in one go...2 yrs ago...now i would.

regarding the AAR: you need some sort of 'RPM enhancer' for cold starts. The bitz kit uses the AAR, but i threw away mine, as it was faulty...just like EVERY other component of this miserably complicated 81-83 CIS system. You deffo need something: the software can provide fuel but cannot provide air...so you need a device that can add air to the cold start. Keep your foot on the accelerator is the easiest solution, but also not the most handy solution.
I replaced the AAR with a hand throttle from an earlier car. Super simple solution. Later i will study the proper implementation of stepper motor idle valve, but i'm not in a hurry.

So, because i did not need the AAR, i went a step further and deleted the whole vacuum mess behind the fuel distributor: the decel valve, AAR, AAV, and the trombone vacuum pipes are all gone. don't now if that is relevant in your case, because you might go ITB immediately.
Also, i went a step further in the cleanup and deleted the fuel accumulator. (not necessary for EFI)

For me, the biggest issue was talking myself out of the idea that throwing away the CIS is bad for the value of the car. With prices these days it's so easy to get into a spriral of 'ooh, gotta keep it stock, gotta keep it perfect'. EFI costs 3k minimum, but you probably lose value...gotta put that out of your mind. Gotta think pragmatic: you want the car to start always and run great.

cheers jan

[BoxsterGT]

Here is an alternative.....





.......with the full Bitz EFI conversion using as much Carrera 3.2 and Metric lines & fittings as possible and keeping this beautiful 911SC as original as possible.

Len dot Cummings at verizon dot net

[shamrok]

Quick update, I have the motor out to clean up some oil leaks, do a valve job and to swap the CIS for the EFI and ITBs. Going through all the stock wiring, I'm looking to eliminate most of the factory stuff and integrate it into a Bussmann fuse/relay box. Also decided I'm going to go wasted spark with Denso COPs. A few questions for the experts...

- Any issue with mounting the Microsquirt and fuse/relay box in the engine bay? I was thinking where the original fuse panel and heater relays were.

- What factory sensors do I need to keep or account for? I'm fairly sure I can eliminate the cam cover sensors (CIS cold start related?) from each side. What about the thermo valve in the oil breather? Can I just remove this and plug the hole with a bolt or is there some benefit to keeping it?

- I'm planning to re-wire the fuel pump with a traditional relay at the rear Bussmann panel, any gotchas here? Is the stock fuel pump just a simple two-wire (hot and ground) arrangement or is there anything else I need to worry about? I have a wiring diagram but not a legend for some of the symbols and diagrams Porsche uses.

Thank in advance!

[LeftCoastErik]

Get an aeromotive FPR. The Summit ones go bad quickly, I had three start leaking within a month. Clewett sells a trick ICV setup that works great, but I have been able to get several cars to run and start well without it. Recommend crank trigger for the cleanest signal. Consider talking to Al at x-faktory as he sells kits that are pretty comprehensive and will save you time and probably money too.

[shamrok]

Thanks, I guess I could have updated that as well. I have everything now and working on the wiring harnesses now. I went with a 36-1 crank trigger wheel and Ford VR sensor for signal and a Tomei FPR.

For cold start, I've read from enough people saying they don't use anything, that I'm not going to go with anything for now. I have my eye on the Clewett setup if I think I'll need it later. For injectors, the Denso ones didn't fit (too short), so I went with 31lb Bosch units (PN 0280155831).

[jpnovak]

Microsquirt will work great here. This is my most commonly installed system. Be aware that just about any EFI system will leave you a bunch of unused wires. Don't be afraid to cut/tape off any that are not used. If you want a hidden install, the microsquirt will fit in the tunnel access under the shift coupler. Stealthy.


Check with your ITB source for injector requirements. They come in different heights and diameters. I am a fan of the Siemens Deka injectors or Injector Dynamics. the ID are way more expensive.

Don't fall for the trap of buying gigantic flow rate injectors. Your SC will never need more than 30#/hr unless you have major mods. You want the smallest injector that meets your HP/flow rate needs. Its all about maximizing dynamic range.

[wreckah]

i mounted the microsquirt under the passenger seat, where the 1981 lambda unit was. The microsquirt manual states that you should not put it in the engine bay as it is not waterproof nor heat resistant...but people here claim that the engine bay is ambient temp...so might not be a problem. I would not do it myself.

I put the standard 'non porsche' fuel relay in the front fuse panel, as that's where the fuel pump is...you also need a wire from the microsquirt to this relay to have the 2 second cutoff at startup etc...stock fuel pump is simple + and -

cold start...depends which climate i guess, but i would find it impossible to drive the car without cold start feature here in Belgium. I went with a hand throttle from early car to keep things simple.

I went with 36-1 wheel too, VR sensor, and ford edis wasted spark, and crown vic V8 spark plug wires + resistor plugs. I tried briefly to incorporate COP's with an additional EDIS unit, but never got it to run...it's a big wiring mess as well with 2 EDIS units...maybe got the firing order wrong with all these wires running about, so went back to simple plug wires.

[shamrok]

Yeah, I saw the bit about running some silicone sealant around the seam of the Microsquirt, which I intended to do. I'm going to retain the factory plastic housing that covered the stock fuse panel and relays back there, so I think it'll be alright.

For cold start I'm definitely back and forth on this one, as the weather here in WA is similar to Belgium sometimes (I used to live right outside of Roermond, miss it every day!) and I like to drive the car fairly regularly when it's not snowing. But I'm going to risk it...it looks like adding a solution later is easy enough.

[shamrok]

Those that have controlled ignition, what VR sensors did you go with? I bought the crank pulley, distributor filler, and sensor mount through goingsuperfast, but none of the sensors I’ve tried will physically fit the mount, they’re all too thick. Any ideas?

[jpnovak]

Ford EDIS VR sensor works great in the GSF bracket.

[shamrok]

I’m doing something wrong then, have tried one from a Taurus and a Ranger and neither fit. Will keep hunting tho. Thanks!

[jpnovak]

Use the sensor that Albert recommends on his site.

2004 Ford Focus ZX5 ZX3 2.0L motor.
MOTORCRAFT Part # DY913 {#F5RZ6C315AA}

[shamrok]

Perfect, my Google-fu definitely failed on that one. Thanks!

[wreckah]

yes, i got the sensor from EDIS-6 kit and it's a ford piece iirc

[shamrok]

Well, I was putting my lower valve cover back on, hoping to get the motor back in the car this weekend and finish up wiring the sensors...and there it was, just laying there mocking me. PO told me they were replaced at some point but didn't have records. But there it was, being all non-magnetic and stupid.

As far as I can tell, it's just the one but it's just a matter of time with the others. Sigh.

[pampadori]

Welcome to the club! Found my broken studs trying to install my cop and plugs as I was fitting my itb kit. You'll get thru it and become intimately familiar with your car as a result. I look back on the motor rebuild very fondly. One of my favorite car related experiences!

[wreckah]

well yes, been there as well...bought the car with a slight oil leak, and couple of months later, first valve job, i found 3 broken studs.
i had mine fully rebuilt to stock specs...pricey...but while you are in there you can do so much stuff: i did clutch, the heads were redone (they found a broken valve spring as well), the case was split and crank inspected/polished, new bearings everywhere, new headstuds everywhere, new seals everywhere, new exhaust studs, cleanup the metal cooling pieces, etc etc etc
i did not dare to do all this myself, and i am happy i got it done prefessionally, even though it was a huge blow to the wallet...but it's only money, right?