How to fine tune TPI on 94 Mariner EFI 2.6l

[THEFERMANATOR]

I just went and rechecked and it is the blue wire and tan wire in the TPS that are used for the voltage reading. Disconnect the port head sensor(the one with 2 wires), backprobe the blue and tan wires with a good voltmeter set down to read less than a volt accurately, turn the key on but don't start it, adjust the sensor to .25 volts optimum(.2-.3 is acceptable range, but .24-.26 is best for a baseline), tighten it down and re-check then button it back up and run it. You may need to make some small adjustements to it to fine tune the idle mixture, but ALWAYS do it with a meter hooked up as you will see how touchy the adjustment is.

[Vic]

Thanks TheFermanator, I had Phatdaddy come by with his voltmeter. That thing is touchy. We got the base line set, but no matter where we set it, we can only get 5.25 volts at WOT. The book says it should have approx 7.46 I wonder if the TPI is bad?

[THEFERMANATOR]

You did disconnect the port head temp sensor correct? If not that will throw the adjustment WAY off and make the TPS test bad. Also make certain the throttle is going full open. The link and sync is pretty critical to get them to work right.

[Vic]

No, I didnt print your instructions so I went by the manual I had handy that said blue/tan lead wire. Sorry I'll recheck it. I did see those black/tan wires coming out of the port side. You think I should disconnect both blue/tan and black/tan maybe?

[THEFERMANATOR]

The blue and the tan wires in the TPS are the ones you measure to get your reading. The port side sensor should have 2 leads coming out that are tan with a black stripe on them. Disconnect both of them and re-check your adjustment.

[Vic]

Thanks again THEFERMANATOR, Got the correct leads disconnected this time and I got it set to .25 on the money. The wide open throttle is 6.25 definetly runs better at this setting.