[bosscar]

dan_xr4

I don't see anything for posts #23, #24 and #25. But now I see that I can read all the posts by trying to post a reply. When I go to post a reply, I can now read all of the previous posts.


bosscar

When I was replacing the ECU pigtail connector and swapping all the wires over one by one, I did just leave the #41 wire in the same spot where I found it, but that was my initial question, is it actually functioning?  I kind of doubt it.  I do have all of the original parts saved from the SVO conversion done back in 1986, the small VAM the smaller tube to the turbo and the original ECU.  All in the boxes the SVO parts came in.  If I go back to the green top injectors, I could put all the original parts back on the car, but I'm not really inclined to do that.  I need to find my Ford Motorsport article that had all the instructions on the pin swaps.  There weren't many pins to move and only one splice to put in the premium fuel switch option.  Maybe there is some note on that #41 wire.  I hope.


dan_xr4

I am not recommending that you go back to your old controller.

You probably don't need a connection to the PJ EEC-IV at pin #41. You have been running the new PJ EEC-IV with the old harness and it was working. The PJ EEC-IV probably has nothing connected to pin #41 inside the control computer. You only need a connection from the PJ EEC-IV Pin 21# to the Throttle Air Bypass valve solenoid.

You can test your old control computer EEC-IV at pin #41. You can measure the resistance between pin #41 and battery hot (Pin #37 or Pin #57). And you can measure the resistance between pin #41 and body ground (Pin #40 or Pin #60).

You should run this test on your PJ EEC-IV as well.

I did this on my PE EEC-IV and found that pin #41 was not connected to either the battery hot or body ground.

I think you correct that pin 41 probably doesn't do anything on the newer ecu's.  I wish I could find my old motorsports catalog that had the instructions just for my peace of mind.   Maybe there was mention that 41 becomes unused or something and not used anymore. Thanks,  Jim

[dan_xr4]

Here are the wiring instructions from the 1986 Ford High Performance catalog:

In addition to the component changes, you'll have to affect a few wiring mods. The Mustang SVO vehicle incorporates the use of a premium/regular unleaded fuel switch in order to signal the EEC-IV module so that maximum safe performance can be obtained under all engine operating conditions.
In order to substitute the Mustang SVO EEC-IV module and maintain this feature for accurate engine function, a jumper wire or switch is required between two pins on the EEC-IV module harness. Connecting a wire between EEC-IV pin No. 30 and EEC-IV pin No. 46 will signal the EEC-IV module that premium unleaded fuel is being used and that maximum performance is desired. Opening this circuit signals the EEC-IV module that regular unleaded fuel is being used and accordingly less performance from the engine is expected.
Also, the Mustang SVO vehicle incorporates the use of a turbocharger boost control system so that maximum safe performance can be obtained under all engine operating conditions. Since this feature is custom-tailored to the Mustang SVO, it's possible that some boost-related drive surge may be present after the substitution of the Mustang SVO EEC-IV module into another car line. If this occurs, the following modification to the wiring harness can be made to eliminate the problem.
At the large No. 60 pin wiring connector to the EEC-IV module, cut the wire going to pin No. 32. Now, attach a single eyelet terminal connector to the end of the wire leading to the vehicle wiring harness. Using a sheet metal screw, securely attach the eyelet terminal to the sheet metal for a good ground connection. Lastly, tape back and securely insulate the remaining wire end going into the large 60 pin wiring connector of the EEC-IV module. That's all there is to it.

Only two wiring modifications and there is no mention of any modifications for pin #41.

[bosscar]

I finally found the 1986 article on how to upgrade the 83-84 cars to a 85 SVO ECU (PJ probably), and there is also mention of 85 Merkurs, Cougars and Thunderbirds using the 85 1/2 ECU (PE probably).
They don't give any part numbers which is strange because I thought their parts list is what I used to make the changes back then.  No mention of PJ or PE computers, etc.
Very simple instructions too, which I don't remember very well.  I thought there were more pins I had to move.  Take a look at the instructions.  I wish there was some mention of the #41 wire for the air by-pass valve being unused on the new ECU.  And the original diagrams don't even show a #32 or what it did.  Or for that matter, what did the #30 wire do before being attached to the #46 for the premium fuel switch?  The #30 and #32 wires are there but no mention in the wiring diagrams of what their original purpose was.  I bought a new air by-pass valve (actually made in the USA).  The idle hangs too high for too long when you let off the throttle, sitting and driving.  Seems like the valve is sticking again.  I changed it a couple times over the years for that problem.  I replaced the connector years ago and both wires are white.  Does anyone know which color wire goes on which side of the 2 pin connector?  Or does it matter?  I just want to verify if I wired it correctly back in the day.  Gray and White on one side and Red on the other according to the diagram.
1986 ford hi performance magazine by jim k, on Flickr
svo upgrade instructions 1986 by jim k, on Flickr

[Paul LeDuc]

bosscar, do you know what issue (mo/yr) that Ford High Performance magazine it is?
I'd like to look for a copy of it.
Thanks

How is it going with the posts? I brought back the content I could with the 'edit' option.

[Chuck W]

How is it going with the posts? I brought back the content I could with the 'edit' option.

Posts 23-24-25 aren't showing up still. At least for me.

[bosscar]

bosscar, do you know what issue (mo/yr) that Ford High Performance magazine it is?
I'd like to look for a copy of it.
Thanks

How is it going with the posts? I brought back the content I could with the 'edit' option.

I think it was just a one time issue for 1986 thru Peterson publishing.  Must have been a deal with Ford Motorsport and Peterson to put the SVO parts catalog on the magazine rack for people to get a copy easier than trying to order one thru the mail or find an SVO parts dealer.  Back in 1984-85 I made our Lincoln-Mercury dealership a Ford Motorsport dealer back then and we had these to sell.  Even our invoices had the Ford Motorsport logo on them.  I think we had to buy a certain amount of inventory to qualify to become a dealer.  It wasn't too hard to do since I was sprint car racing with a Ford engine, and we had another customer who was using Ford engines in their Southwest tour race car.  Those kind of parts are pretty pricey and it kept us as a dealer for quite a few years.  I still have some Ford SVO engine parts new in boxes.  One 351w block, Yates heads, etc.

[Paul LeDuc]

Thanks.

[Paul LeDuc]

How is it going with the posts? I brought back the content I could with the 'edit' option.

Posts 23-24-25 aren't showing up still. At least for me.

Chuck, try what I did. Hit the 'edit' button, 'quick edit' then 'save'. You don't need to do anything else; it brought back the content for me.
I see what you mean, 23.24.25 were empty. i did the edit thig and 23 and the content came back. I still can't figureout why...

[Chuck W]

I tried that originally, as well as just now. Still empty.