Testing MAP and TPI sensors

[l2sail]

Hi, I have a thread going on fuel injection problem but its getting long and thought Id break this off as a seperate item. Since I dont have a compression gauge or a timing light and havent had a chance to get them I tried testing what I can. On Wells Manufacturing Site it described how to test the MAP sensor and the TPI. Heres what I found:

MAP Sensor, had a hard time finding it, its located behind the firewall by the wiper mech area. The test basically consists of disconnecting from the 3 wire connector, jumpering the two outer wires and monitoring the voltage on the center pin to ground. With just the key on (engine not running I got 4.9 volts which it indicates as correct) I could not start the engine and thus couldnt check to see if its varying correctly.

TPI: This test was just measuring the resistance between pins 1 and 2 and between 2 and three with it unplugged from the harness. THen move the throttle through its range to WOT

Pins 1 to 2 at idle 2.79k
Pins 1 to 2 at WOT 5.65K
Smooth change in resistance, no drops through range.

Pins 2 to 3 at idle 3.82K
Pins 2 to 3 at WOT 3.82K
Same through the range.

THe test says both should vary smoothly. Im thinking this could be my problem.

I also tested the voltage change with the key on.

Pin one appears to be the sense lead, at idle it was 3.38 volts and at WOT was .21 volts. THis is opposite of what the test described should happen, says it should be near 0v at idle and increase going to WOT. The second pin had 4.37v always and the third pin was at .01v always.

So is the TPI the problem or is it different cause its a french car? Im french so I can make fun of it, but really any thoughts on this??

Thanks, Phil

[foureyedbuzzard]

http://www.se-r.net/engine/tps_voltage_adjustment.html

[l2sail]

Hi, thanks for the link, I read it but I dont want to go moving things if they are correct. My issue is I do not know what this one should read for an output. As you can see from above its basically going in the opposite direction. IE at idle its a high voltage and at WOT its almost 0v. I dont have the leads swapped, I double checked.

I also for kicks held the TPI lever down to get a reading of .4v and then tried to start, its still acting the same.