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Category: General 2.3
> Could someone that has done this swap successfully explain to
me how to do it?
> What parts are needed besides the TC EEC and Brown topped injectors?
Here's my original post on this subject. I left all the headers in it, so you can see how long ago it was.
NOTE: You need the big VAF, too.
Remove your boost control amplifier, and control you boost manually, if you put this eec in.
Dave
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From: Dave Compton [DCompton@JNPCS.COM]
Sent: Friday, June 13, 1997 9:16 AM
To: Merkur Listserver; SVO List
Subject: 87 T-Bird Turbo Coupe EEC-IV into an 88 XR (long)
This message pertains to installing an 87 Turbo Coupe EEC-IV computer into an 88 XR, both automatics. If you don't care, DELETE it now.
Why would I want to do this?
Because:
1) Turbo Coupe's had an intercooler, and have the more aggressive spark tables. People
with intercoolers added, take note.
2) Turbo Coupe's had the bigger Vane Air Flow (VAF) meter. so it has the bigger air
tables, ala "PE" computers, and understands the higher flow of air.
3) SVOs never had automatics, so it was my only choice, for a hopup.
4) I got one of these computers for $20 at Carlisle,and I'm brutally cheap. If this works,
I have saved the cost of a Superchip, to provide these different tables.
I also picked up an intercooler at Carlisle, which started this ball rolling. If you didn't have an intercooler, I imagine this would not be a good thing to do. The aggressive timing provided by the TC EEC, thinking it has cooler air than it does, would probably lead to detonation. Not a good thing.
Granted, TC autos had low HP, but nonetheless, had these desirable features. The HP was lower than the manual transmission cars, supposedly, because of a slightly smaller lift cam (never verified), and lower boost.
Also, as near as I can tell, all these changes would also apply to a manual TC EEC into a manual XR. There were no annotations on the schematics for Auto vs. manual other than Pin 30. It "appears" to tell the EEC whether the car is a manual or automatic. Tied high for auto, low for manual. I'm not 100% sure on this function, but that's what it looks like. I'm wondering if the EEC has tables for both autos and manuals in it, and you select them with this pin. Dunno. That would be nice...
Other years of XR4ti may be different.
Disclaimer: This is "Information". If you use it and ruin your car, that's called "Execution". I will not be liable for YOUR "Execution" of MY "Information". Do your own homework. Nuff said.
The XR wiring needs to be changed to match up to the new EEC in the following areas;
1) The bigger VAF meter from an SVO or an 87-88 Turbo Coupe needs to be installed. Duh, that's reason #2, why we're doing this. 2) An additional Air Charge Temperature (ACT) sensor needs to be installed in the intake manifold. This would require a late manifold or some fabrication, in the original manifold. It's output would go to pin 25. 3) The output of the Vane Air Flow (VAF) meter needs to be moved to pin 27 from 43. 4) The output of the original ACT sensor needs to be moved to pin 43 from 25. 5) A Brake On/Off (BOO) input needs to be installed. This is actually only a wire that needs to be run to the switched side of the stock brake switch, so that +12v is applied when the brake pedal is depressed. This would go to pin 2. 6) A Vehicle Speed Sensor (VSS) needs to be added to the transmission. This shouldn't be hard, I believe it just slides in the speedo cable hole in the tranny, and then the speedo cable plugs into it. I'm not sure yet, though. It's positive output goes to pin 3, negative output to pin 6. I'm gonna try to hijack the Cruise Control speed sensor output, first. 7) An octane switch needs to be added to pin 24 of the EEC. Tie to SIG RTN (ground) for Premium fuel mode. Tie high for crummy gas. 8) Pin 32 needs to be moved to pin 31. This is the boost control solenoid line. 9) Pin 35 needs to be moved to 33. This is the EGR control solenoid line. 10) Pin 42 wants to see the A4LD transmission's kickdown solenoid. 11) Pin 53 wants to see the A4LD transmission's torque converter lock up solenoid.
Note: There is no feedback from the A4LD transmission. The EEC can only detect the current draw from these outputs if at all, to tell if the tranny is there. A resistor of undetermined value could simulate this to prevent an erroneous error code. The resistor should successfully fool the EEC.
12) Pin 52 puts out a ground to energize a relay that turns on the secondary cooling fan. This could be re-wired to drive the stock front fan relay. Or not. 13) Pin 55 puts out a positive voltage to energize a relay that turns on the primary cooling fan. This could be re-wired to drive the stock back fan relay. Or not. 14) Pin 35 puts out a signal of unknown type to the Programmed Ride Control Computer. This function is named ACL. From what I know of the Turbo Coupe, above a certain speed the electric shocks switch to Firm. This output could be used for something "cool", but I haven't gotten that far yet. Maybe an intercooler fan, that shuts off once you're rolling along at speed...
So, for the cost of another ACT, and a couple of hours work, I should have the "bigger" tables in the computer. The intercooler and big VAF mater, should already be on your list of necessary mods.
I have not done this yet. I'll post when I do, and what I find out. The above modifications should remove all bogus error codes, and make the EEC "think" it's in a Turbo Coupe. The G-Tech meter will tell whether it was an improvement.
If anybody has a schematic for a late SVO, I'd appreciate a fax of it. The Turbo Coupe is VERY different than an SVO, so there isn't much info you could extrapolate about the SVO from this info.
Dave DCompton@JNPCS.COM
Northern VA, USA
"Hey, I resemble that remark!" *************************************