good idea but it didnt fix anything. ran the same. ran worse plugged in.

 

OK.

My wiring "pin outs" from the factory books I have on hand, and what I have used on many over the years, is

ECU pin:

7 = TPS wiper.
19 = TPS centre, and also ONE terminal of the CTS.
20 = TPS end, and also one terminal of the ATS.
5 = 2nd terminal of the CTS.
21 = 2nd terminal of the ATS.

It is that simple, and if wires are crossed havoc follows??.

 

would you happen to know off hand if pin 19 is the high or low side of the TPS? im running the m ustang unit which makes it more of a pain.

 

I am thinking Hi side??.

I have attached my diagram, maybe it will help you??.

If you cannot magnify it, let me know, I will do a hand drawing of the TPS section and post that here??.

 

I found another 16CU box in my garage, apparently I have 2 of them now...

 

M90, this all started a long time ago when you replaced the Bournes pot with the Mustang pot. We've pretty definitively ruled out the CTS so it's got to be the pot. I have a spare Bournes pot I can send you for troubleshooting if you want -although it seems like more of a wiring issue than the pot itself. PM me if you're interested.

 

im interested. PM sent

 

Pm replied, but I advise before I send you the pot to triple check the wiring, and also when you reinstall my pot to check it again to make sure everything is going to the correct pin. I almost wonder if you're simulating a WOT condition by either sending afull 5v to the ECU or no signal at all (not sure which would simulate full throttle).

 

well if i switch the high and low side around, it runs really REALLY bad.

 

M90, have you actually done this yet? if not, please do, as this 'running without a CTS connected' is the best diagnosis of your problem we have so far, and as far as I can see you are ignoring it. Just fixing the underbonnet wiring proves nothing.

Greg

 

He did, he posted above that it didn't help and ran the same when plugged in.

 

Thanks Darel.

it made, literally, no change at all.

Having the CTS plugged in if its cold, makes it idlessmoother, but it will not rev at all and wants to bog when you open the throttle. when the engine is up to running temp, plugging the CTS back in kills it dead.

 

If anybody could verify this for me, it would be a big help. i vaguely recall seeing the CTS wired through the high side (green) and the IAT wired through the low (yellow), but perhaps its just my imagination.

this diagram shows exactly how its currently wired.

 

I am not sure on your diagram which is which, but, according to my North American version factory manual wiring diagram:

TPot wiper output goes to pin 7
Tpot 5v input comes from pin 20 which also feeds ATS with 5v
Tpot output non-wiper (ie after the 5v has gone through the resistance, but not including the wiper output) goes to pin 19
CTS output (ie after the 5v has gone through the resistance of the sensor) also goes to pin 19
CTS 5v input comes from pin 5
ATS output (ie after the 5v input has gone through the sensor) goes to pin 21

Pin numbering starts from RHS BOTTOM as you look at the pins (ie the other way from normal reading of words on a page). Pin 5 is therefore the fifth pin along from the bottom row RHS. Pin 7 is the seventh pin along from the RHS bottom row. Pin 19 is the first pin on the RHS top row. Pin 20 the second along from the RHS top row. Pin 21 is the third from the right on the top row. All as you look at the ECU pins head on.

Greg

 

whups, sorry. on my diagram green is low resistance, yellow is high resistance and red is wiper. colors matching the TPS harness. i think the high resistance side (yellow) should be going to the IAT and low resistance (green) should be going to the CTS but im not sure and the schematic doesnt specify which side is high or low.

 

A TPS provides a voltage signal back to the ECM.

Since you swapped the TPS for a Ford part, make sure the three wires are not switched around. Not all TPS sensors have the wires in the same sequence.

 

as far as i can tell theyre correct, and i did a bunch of research trying to find the correct sequence. yellow to high, green to low, and red to wiper.

i will say this. the other day i had a little bit of slop in the throttle linkages, from when i changed the plugs, and when i touched the gas the TPS turned but the throttle plates hadnt yet absorbed the slack and the motor started to bog out from over enriching. once i took every last bit of slack out of the linkages, the phenomenon was gone.

 

Take O2 sensors out and run your motor with them on the side. I want to see if relieving exhaust manifold pressure will help...

 

i had the exact same thought, but wasnt sure if the o2 sensors would relieve enough pressure to make a difference. since you had the same idea, ill give it a shot.

 

They will do a huge difference if your pre-cats are partially clogged. Keep in mind, that motor will not run 100% right, with both sensors out, however you will feel immediate throttle response difference.