SHO Components for 914 build

[3d914]

I've started laying out a wiring diagram for the 914-SHO and I need some clarification on various components that are shown on the Dennis Wolfe Wiring Diagram. What are some of these (marked with ?), and can I get the various control modules to run without these:

• inertia fuel shut-off switch
• vehicle speed sensor
• trans. range sensor (?)
• turb. shaft speed sensor (?)
• trans. control switch (?)
• power steering pressure switch
• pressure feedback EGR sensor (?) I'm not using the EGR
• on/off brake switch (?)
• clutch engage switch (?)
• canister purge solenoid (?)
• electronic vacuum regulator (EVR)

The Bosch electric fuel pump for the Porsche is rated at 34psi. The specs for the SHO fuel pressure appears to be 33-39psi. Is the 34psi marginal or should it be sufficient?

Also the fuel press regulator doesn't appear to be adjustable. Is there an inline control to adjust fuel pressure as needed?

That's a lot to start with, but thanks for the help.

 

[Off Road SHO]

I had a tuner guy put a chip in the Other Woman's computer so all of the items you listed have been "tuned" out of the main programming.

The Bosch 34 PSI unit will not work. Get one from any wrecked Ford with fuel injection and the frame mounted pump that had a return line. They put out a good 75 psi to start. The fuel pumps for the returnless fuel injection systems wont work.

The FPR is not adjustable and doesn't need to be untill you go forced induction. And you WILL go Forced Induction; it's just a matter of time.

Tom

 

[ycode90]

Just get an MTX harness and xj2 most of your list is ATX only or wont cause CEL.

 

[rbruso]

I have an MTX harness (still on car at the moment), but the car has California emissions. If you get a non-California computer the harness would work with the EGR wires removed.

The Brake On/Off and Power Steering Pressure Switch only throw codes during the KOER test, and those codes are only informational, not stored. The clutch engage switch should be for the A/C clutch.

I believe the canister purge solenoid can throw a code if it's not there, but I'm not 100% positive.

The inertia switch could be bypassed but you could transplant one. It kills power to the fuel pump in case of an impact. The speed sensor input is used as an input by the computer to adjust idle between coasting to a stop and being stopped.

Do you have a Helms manual or the Probst EFI book, by any chance.

 

[3d914]

Thanks guys.

Tom, can you PM the contact info for your tuner? There are a I hear you on the FP. Don't most Ford's (like the SHO) have the FP in the tank? I was thinking about our Windstar FP but I'm certain it's inthe tank also.

I would like to keep the clutch engage switch capability as I want to add AC down the road. Does the ECU monitor that for idle adjustment or to cut-off compressor during hard accel?

The engine and ECU I have is ATX (wasn't that correct Tom?). I've not found any manuals yet on SHO. The taurus manual might have some, but the odd models don't get covered well - especially for wiring and schematics. I'll look for the two you've suggested bruso. I do have the Bosch FI book.

 

[Off Road SHO]

I don't remember what I sold last week, let alone 3 years ago.

The Clutch switch is a safety interrupt switch that will not allow you to crank over the engine unless the clutch pedal is pushed in. The AC cutout switch is different.

Look for a fuel pump from a van or F-150 from the early to late 90's. Usually frame rail mounted, underneath the driver. Some were quick connect fittings, some were threaded flare.

My tuning guy, Robb at Forced Induction Tuning, only does the chip as part of the dyno'ing process. You don't need a chip if you're staying NA.

Tom

 

[rbruso]

I don't think the clutch pedal switch is included in the ATX harness, but I haven't really played ATX much. I believe the clutch pedal switch interrupts the starter circuit separately, not through the computer. The A/C clutch switch definitely feeds into the computer as a feed-forward switch to let the computer know to bump the idle, same as the BOO and the PSPS. There is also the WOT A/C cutoff, but I don't know if the computer sends that signal.

I'll dig out my EVTM tonight to try to verify this. (or to find out I'm in left field. Whichever works )

The Helms manual is the official shop manual. It's published for each year separately and available in two parts (in '89, at least): the SHO addendum and the rest of the Taurus/Sable fleet. The main book is 1 1/2-2" thick, while the SHO addendum is significantly thinner.

There is also an official Ford EVTM (Electrical & Vacuum Troubleshooting Manual) for each year that goes way further into wiring and plug identification than the main manuals.

Both sets pop up regularly on eBay. You can borrow mine if you'd like, but I'll need them back eventually. They're my friends.

Oh, and to verify which computer you have, look for a sticker with a string like 'D4UI' or 'XJ2'.

 

[Shovert]

94 wiring diagram I am using. I think pointed out by someone here i Russian site. Odd isn't it. My anti-virus program has not found it bad so I assume ok. If I am wrong please let me know.
http://taurus-club.ru/manuals/Ford_Taurus_1994_wiring.pdf
Hope that helps. maurice
Edt. During my searching found this. Since I converted to RWD. I had to bypass the trans switch. There is a resistor in it that has to be there. 400 ohms. Mention this site PDF. Page 8. I just made a loop of wire with 400 OHMS of resistance. Maurice
http://www.speedfreaksgarage.com/jeff/ATXtoMTX.pdf

 

[rbruso]

I guess errors sometimes slip in, even for Ford documents. The '89 EVTM shows a Backup/Neutral start switch labelled 'Closed with ATX in park or neutral' for the SHO. I'm gonna go see if I can find an ATX somewhere on my '89.

Anyway, turns out there are two switches on the clutch pedal: The one I knew about and the one Tom was talking about. So, anyone know if the clutch switch input to the computer at pin 30 (MTX) helps with starter disable or if it is another feed-forward to the computer to bump idle?

For the MTX, pins 16 and 23 connect to the A/C clutch coil. I suspect these two connections serve both as the feed-forward signal and as the WOT cutoff.

 

[3d914]

shovert, thanks - I found some other helpful stuff on their site. Good to have a daughter that speaks/reads Russian.

bruso, thanks for the MTX pins for the A/C clutch. I hope they're the same for the 95 ATX. I ordered a Haynes manual - hopefully it has schematics.

Planning to bench run the engine with all the necessary harnesses prior to installation. Much easier to sort things out that way. I hope all these details don't become quicksand.

 

[Off Road SHO]

Gerard,

I have the EVTM's for the automatics and the mtx's. When you get ready to wire, I'll hook you up. I also started a thread for wiring a SHO motor in Something Else. I'll see if I can find it for you.

Edit: Here it be. http://www.shoforum.com/showthread.php?t=115598

Tom

 

[3d914]

Excellent write-up Tom, Thanks - that'll save some time & questions.

Do you have the EVTM's in electronic form (ie; PDF)? I've confirmed from my earlier notes that this was a 1995 ATX engine. I'm still digging out all my SHO parts. I'll get the various component IDs and post just to verify.

Best Regards

 

[3d914]

OK, I'm just a little bent :banghd:

Just went through all my parts boxes and I'm missing a few of the major ones; ICM, MAF & PCM.

So here I go, I need to verify if my list of electronic components is complete so I can go parts hunting again. Aside from my assembled engine, with engine harness installed, I also have the main harness that ties to the PCM. I'll need the following:

• PCM-power control module
• MAF sensor
• Oxygen sensors (2x)
• CCRM-constant control relay module
• Ignition coil pak
• ICM-ignition control module (DIS)

I also plan on using the following in place of the 914 items:

• SHO fuse panel
• SHO Power distribution box
• CCRM for Fuel pump pwr
• Custom relay board for:
  • Heater fan
  • head lamp motors
  • Aux driving lights
  • Fresh air fan
  • light dimmer

Is there anything else I've overlooked?

 

[rbruso]

I know of a place you can find all of those things...:angelnot:

I'd recommend new O2 sensors. Are you planning to switch to an MTX computer? If so, the recommended computer is an XJ2, which I don't have. I do have a spare MTX CCRM but if you have an ATX harness it might be easier to track down the appropriate ATX-coded CCRM.

I assume by ICM you are referring to the DIS module that mounts to the intake crossover?

 

[Off Road SHO]

Gerard,

What happened to all that stuff? I remember you had a lot of it in a box that you took with you. I hauled the engine on that wodden frame I built.

In either case, you will spend an inordinate amount of time trying to stuff all the original SHO pieces in your 914.

What you need:

Coil Pack. I have one.
Computer. I have an auto one, reccomend switching to an X2J (see next)

Wiring harness. Build your own. It's a lot easier than trying to make the factory harness work. All you need is the engine harness that attaches to all the parts; sensors, injectors (and) the engine bay harness for the connectors that connect to the engine harness. I have all those connectors, but you could easily grab a complete one from a junk yard. On The Other Woman, I wanted no wires to show on the outside of the engine so I made a completely custom wiring harness that was time consuming and not very maintenance friendly; don't do it that way. Make it so that you can disconnect your engine or any of its components easily. I can help you on the wiring, it's not difficult.

CCRM. I have some, but would advise against using one. Use readily available standard relays for fuel pump, ignition and fan(s). Cheaper to replace than a CCRM.

MAF I have one, and the rubber connecting hose.

DIS I don't have any that are worth using in a custom application like yours. Go to junk yard and get one off of a SHO or T-bird.

O2 Sensors. Buy new ones.

Don't use the stock fuse panel or power distribution panel, use your custom one.

I would advise you to get the engine mounted and the more difficult-to-run plumbing done first, then find places for the fuse, relay panel, computer and coil pack, then connect them all up.

Tom

 

[Shovert]

Unsure how this helps if does. On mine I tried to change a 94 SHO harness to fit the Mustang. What a joke. What I did then was use the 93 2.3 Mustang harness and pin in the SHO necessary. I was surprize how few wires I had to add. Just idea thrown out there. Pitures in link. Maurice

 

[rubydist]

I guess errors sometimes slip in, even for Ford documents. The '89 EVTM shows a Backup/Neutral start switch labelled 'Closed with ATX in park or neutral' for the SHO. I'm gonna go see if I can find an ATX somewhere on my '89.

Anyway, turns out there are two switches on the clutch pedal: The one I knew about and the one Tom was talking about. So, anyone know if the clutch switch input to the computer at pin 30 (MTX) helps with starter disable or if it is another feed-forward to the computer to bump idle?

For the MTX, pins 16 and 23 connect to the A/C clutch coil. I suspect these two connections serve both as the feed-forward signal and as the WOT cutoff.

the atx does use an interrupt for the starter to ensure it only can start when in park or neutral. this is in the mlps which is on top of the atx under the lever to the shift cable. the atx pcm also has a rev limiter at 4000 rpm when in park or nuetral, so if you are using an atx pcm on a non-atx car, you need to jumper the mlps such that the pcm thinks it is in park to start and not in park to bypass the rev limiter. fortunately, this is possible, and there is a thread or two on the forum that document how to do this if you need it.

 

[3d914]

What you need:

Coil Pack. I have one.
Computer. I have an auto one, reccomend switching to an X2J (see next)

Wiring harness. Build your own. It's a lot easier than trying to make the factory harness work. All you need is the engine harness that attaches to all the parts; sensors, injectors (and) the engine bay harness for the connectors that connect to the engine harness. I have all those connectors, but you could easily grab a complete one from a junk yard. On The Other Woman, I wanted no wires to show on the outside of the engine so I made a completely custom wiring harness that was time consuming and not very maintenance friendly; don't do it that way. Make it so that you can disconnect your engine or any of its components easily. I can help you on the wiring, it's not difficult.

Tom, I'm with you here. I do have the engine bay harness so I can get the connectors from it. As long as the MTX & ATX connectors are the same I can work with the needed pin swapping. I'd like to brake the engine-to-main harness with one/two large connector to make routing and engine drops easier.

CCRM. I have some, but would advise against using one. Use readily available standard relays for fuel pump, ignition and fan(s). Cheaper to replace than a CCRM.

That sounds reasonable. What is the relay configuration used. Here is a pic of the standard Bosch relay used through-out the 914.

Don't use the stock fuse panel or power distribution panel, use your custom one.

Are there components available to build custom relay/fuse panels? I've never looked into this. The stock fuse panel meets my needs nicely, but I'll take your word for it. I do want a covered panel that I can keep in the front trunk instead of under the dash. Do you have some suggested sources for parts?

I would advise you to get the engine mounted and the more difficult-to-run plumbing done first, then find places for the fuse, relay panel, computer and coil pack, then connect them all up.

My plan also. Already started on the engine bar design. Keep in mind that I still plan to bench run the engine before it goes in. So all these components can be connected, tested and configured in advance. I figure I'll be doing the main harness twice; once roughly for test run, then a final version to fit installation. This worked well for me when I did the FI conversion on my last 914.

I get the consensus is to use the MTX cpu; the X2J. Any down-side to this?

Many thanks.

 

[Shovert]

CCRM or as I know as IRCM [Mustang and 2.3 turbo] Here is site with info on it. It has theory of operation and explains relays and diode. May help. Note the wiring diagrams are NOT for a SHO but does explain. I don't think it would be any problems using relays instead of it. I assume no AC. How many radiator fan going to use? Maurice
http://jr.rustecat.com/articles/ircm/assem.html

 

[3d914]

Maurice, thanks for the details. That explanation does help. At this point I'm looking to go with a custom relay board since I have to do a custom fuse panel also. One of the POs on this car had every wire cut and crimped at both front and back firewalls. I'm simply not going to live with that nightmare - so I'm going to rewire the entire car and build new harnesses.

Ohhh the fun never ends . . .