PM-65 and XS questions

[frankinstang]

This project is a 1986 SVO 2.3 transplant into a 1965 mustang fastback. A mechanical inspection of the engine shows that it’s in reasonable shape. The engine is complete except wiring loom and ECU. The goal is to end up with a PiMPXS ECU and coil on plug with the cam angle sensor. I need to budget the purchases so I’ll start with the PiMPXS in batch mode and add COP and CAS in the future. After considerable research through your webpage I have a few questions that I couldn’t find the answers to:

What is the length of the PM-65 wiring harness? I need to install this before I install the engine due to limited access to the firewall and I have to work around the vintage air AC system that has consumed a large amount of available space under the dash.

The PM-65 harness instructions state that there are outputs for oil pressure and water temperature gauges. What are the voltage levels for both of these? I need to purchase gauges that match these values. I’m assuming that the ECU uses the SVO stock oil pressure and water temperature senders.

I want to install a fuel interruption switch (FIS) for collisions in the harness between the ECU and the output relay. I assume that it is OK to pass the ECU output to fuel pump relay through the FIS?

What are the fitting sizes for the flex fuel sensor?

Do you sell replacement diaphragms for the Kirban fuel pressure regulator?

I need mounting brackets for the PiMPXS ECU. Do you sell these?

What is the pulse rate output per-mile for an electronic speedometer output from the ECU?

There is no mention of bypass or filtering capacitors on the input to the ECU. Is this done internally to the PiMPXS?

I need a recommendation on injector size since I’m going to have to change them to high impedance units to match the PiMPxs. The goal is to end up with a Bo-Port stage 3 head, 2.1 cam and upgraded turbo. Is there a set of injectors that can run the stock engine now and still feed the upgraded one later?

Kudos to you for a great webpage and source of info. I wouldn’t have even tried this swap without it!

[Stinger]

I'm not really sure how to measure the length of the harness. It's not installed in a straight line and I don't know what end point you'd want to measure it to if the measurement starts at the ECU connector.

The gauges have nothing to do with the ECU. ECU doesn't read oil pressure (by default anyway) and water temp for the ECU comes from the ECT sensor in the intake manifold while the temp gauge connects to the temp sender (not sensor) in the block. The senders are single wire (grounds through the block/head). The sensors are 2 or 3 wire. So you just select gauges and use the senders that come with them (or you get one of our fancy digital dash systems and save money relative to buying individual gauges while offering more functionality and features (if you're not against having a modern looking dash in a classic car).

The SVO used an fuel inertia switch as well so there is no reason you can't do the same with your car.

Flex fuel sensor fittings are 3/8" quick connect. It goes in the return line, not the feed.

We don't sell the diaphragms as we've never had a customer need one and I've never needed on (still rocking my original one from 2001). We can get them if necessary though.

Since the ECU is designed to be plug and play in applications that already came with ECU's this size/shape, we don't sell a hanger as 99% of customers already have one in their car. You can basically grab a hanger from any mid 80's to late 90's Ford/Lincoln/Mercury if you want an easy solution.

The pulse rate comes from the VSS sensor, not the ECU.

80 lb/hr is as large as we suggest you go on a batch fire 4 cyl unless you're OK with less than ideal idle/low speed stability. If you're planning to run E85 then there isn't really a good solution to the desire to run a single set of injectors for both setups as 80's don't support very much power on E85 and 120 lb/hr or larger won't be happy running batch fire. The other option could be to get an "x" now (so you can run stock injectors) and send it in for upgrade to "xs" specs when you're ready to do the more radical build.

[wesk]

All practical ecu's have filtering caps in there internal power supplies.

[frankinstang]

Thanks for the fast reply!

Item 8 on the PM-65 install instructions has you connect the oil pressure and water temperature senders to the harness. Item 16 gives you wires for the water temperature and oil pressure gauges. Since the ECU doesn’t use them I’m inferring that theses wires are in the harness only for the gauges and have no ECU connections? Likewise for the VSS connection?

Is the mating connector to the FIS connection to the harness included with the PM-65? If not, what is the connector?

Thanks again, I’ll be placing my order in a couple of days.

[Stinger]

Correct on the oil and water wires. VSS signal goes to the ECU and speedo because the ECU can use that signal. This is all the same as it is with the stock ECU.

You can see the fuel pump and inertia switch wiring in the PiMP wiring diagram from the PiMP FAQ, duplicating it should be relatively easy. Pin 22 is used by the ECU and therefore in the PM-65 and PM-66 harnesses:

[frankinstang]

Thanks again, that cleared up a to of questions.  Does the documentation with the PiMPXS include the schematics as well?

[Stinger]

The PiMPxs startup guide does not have the wiring diagram because the ECU is primarily for plug and play applications that already have a functioning wiring harness and the startup guide only covers plug and play stuff. It does include the EEC connector pinout and expansion connector pinout though, along with diagrams and screen shots of settings and such.

[frankinstang]

Does the PiMPXS use the sheet metal attachment as part of the heat sink for the processor?  The real question is can it be mounted in the glove box?

[Stinger]

It's just a ground, not a heat sink.