1996 f-150 302 e4od. I have chased this gremlin for a couple weeks now. The truck warms up and runs/drives fine and then once warm, idles fine but bogs down under acceleration.

I have read multiple posts on this issue and they have been very educational. This is what i've done:

Cap, plugs and rotor.
Checked EGR and it's solonoid, good.
Checked engine temp sensor, good.
Cleaned MAF and Air Temp thing (on the intake box) with MAF cleaner.
Checked Idle air contol on the throttle body, good.

When I checked the TPS I found some strange numbers. I set my digital volt meter to 20V DC (lowest setting before milivolts?). It read .046 at throttle closed and steadily decreased down to .004 at wide open throlttle.

I did this with the engine both off, and while running with the same results. I may be soing this wrong, but I tried to follow the instructions you guys have given and what Fordfuelinjection.com has.

My question is: is the TPS bad and, I have one off my donor truck and is there a way to bench test the donor TPS?

I also checked the manifold vacuum thinking it may be the catalytic converter and it read 20 in.hg(sp?). This was at idle. Do I need to check it under load or do I need to do the drill test before and after the cat to see if it's bad?

Conanski, Subford, anyone have any ideas. I am open to any suggestions and thanks in advance. I will check back this evening with you guys,

 

truly strange,

ok, so tps= 3 wires; ground, 5v reference and signal(usually green). volt range is .99v at idle to~5.0v at wot

i would check the 5v reference while your there, but i would definetly try a different sensor if you have one handy

 

Thanks for the input.

I back probed the red and green wires on the TPS. That's where I was getting the strange voltage readings. I will put the other TPS sensor on today but I just wanted to check and see if I'm doing it right and if you can bench test the sensor before I got started. Four bolts and two screws and I can't seem to get motivated to do it!

 

The TPS is just a potentiometer(variable resistor) so it will display a range of resistance measurements as it sweeps through it's travel. The old TB I have in the garage ranges from about 620 ohms to 4.3k ohms or vise versa depending what wires you measure across.

 

When you got the voltage readings where was your (-) lead from the meter.
It should have been on the ground wire in the plug of the TPS.
You may also have a bad Body or Computer ground.
When something is just not right check the grounds.

 

I tested it with one probe on the red wire and the other on the green one. This may be my problem, but when I tested it with the neg. lead on the ground wire I got nothing. I couldn't find any color codes on fordfuelinjection.com and my chiltons manual had nothing. I will try again tomorrow and let you know. I'll check the grounds too. Thanks for the help.

 

TPS Sensor
359 GY/R wire Sig RTN (Ground)
355 GY/W wire Sensor Information to PCM Computer
351 BR/W Reference Voltage (+5VDC)

GY=Gray
R=Red
W=White
BR=Brown
The first color is the wire body color.
The second color is the stripe on the wire color.

 

kaduh, have you checked your meter to be sure it is ok? a good new AAA or AA alkaline battery should read about 1.6 volts. then a new 9 volt alkaline is about 9.6.