1992 4.2 V8 5 speed swap needs 3.6 parts to work

This info is from JustFourRings.com thread called: "Sams questionable V8 thread"

http://forums.justfourrings.com/viewtopic.php?f=4&t=1596&start=100

If you try to convert a 1992-1994 4.2 V8 quattro to a 5 speed, you'll need to get a 90-91 V8 engine computer with related harness, the TCU computer and harness, and the 3.6 PT intake manifold and injectors and mount them on your 4.2 engine. Then proceed with the 5 speed swap.

You may say, "even the Tcu and harness?"

Yes the 4.2's ECU & TCU talk to eachother, so you'd have to switch both otherwise something will not be happy..

Unless you have access to a Occilloscope and can read all the patterns of signals from a working 3.6 and 4.2 and can figure out where to stick the 3.6 signals into the 4.2 TCU so that it doensn't freak out.

So, theoretically speaking... If I have a 3.6L 5-speed, stock ECU with an ABT chip...
I can drop a 4.2L in there with no issue, keep the transmission, ECU, chip, and harness... and I win?
What about if I have Audi V8Q '93 with automatic transmission ant ABH engine - I just change engine ECU (from PT) and harness ?? automatic transmission ECU and harness stays the same ??
What about other options in Audi V8 ABH, like servotronic, climate control,
ABS... Is this swap will not effect what I just mentioned ?

Yes if you use the PT ECU & wiring AND TCU and wiring you're all set, The rest of the car's wiring stays the same (Servotronic, ABS will not be effected).

So if you have a 3.6 5 speed just drop in the 4.2 and you are 100% swapped. So long as you use the electronics for the 3.6. The electronics do not know; nor care which engine it's controlling.

You *should* also use the 3.6 Injectors. The one on the 4.2 are larger (and again the electronics don't know any better) and the car will run rich all the time. The extra few pound of fuel are to0 much for the O2 sensor to dial back.

While you're at it (and if you listen to Ron) he'll suggests you use the 3.6 Intake too.. the 3.6 Intake is coated inside and out, give you a smoother flow