85 f150 efi

what it does is quite strange. If I'm cruising about 65-70 there is a dead spot in the throttle. The truck will start to bog down and sounds likes it's either flooding out or leaning out. Then I push the gas peddle down just a HAIR and it takes right off like it's fine. Always does it in the same throttle area. The thing that makes me so mad about it is it does not cruising in 4th and at 55 in 3rd. So there is no winning. Haha. It also only seems to do it after the truckIis warm. I assume that's because the computer isn't necessarily factoring in the tps until warm? Either that or the sensor heats up and begins failing.

I seem to think it could be the tps. Any other ideas?

I also would suspect TPS, but it does not ignore it until warm, that is only the O2 sensors. You can hook up a dvom to read the resistance and run the throttle up slowly to watch the resistance. You should see it steadily change, no jumps. If you have jumps in the reading, it is bad.

jebadiah04 said:

85 f150 efi

what it does is quite strange. If I'm cruising about 65-70 there is a dead spot in the throttle. The truck will start to bog down and sounds likes it's either flooding out or leaning out. Then I push the gas peddle down just a HAIR and it takes right off like it's fine. Always does it in the same throttle area. The thing that makes me so mad about it is it does not cruising in 4th and at 55 in 3rd. So there is no winning. Haha. It also only seems to do it after the truckIis warm. I assume that's because the computer isn't necessarily factoring in the tps until warm? Either that or the sensor heats up and begins failing.

I seem to think it could be the tps. Any other ideas?

Click to expand...

Hello and good morning.

Do you have access to a Code Reader?

Boon

jebadiah04 said:

85 f150 efi

what it does is quite strange. If I'm cruising about 65-70 there is a dead spot in the throttle. The truck will start to bog down and sounds likes it's either flooding out or leaning out. Then I push the gas peddle down just a HAIR and it takes right off like it's fine. Always does it in the same throttle area. The thing that makes me so mad about it is it does not cruising in 4th and at 55 in 3rd. So there is no winning. Haha. It also only seems to do it after the truckIis warm. I assume that's because the computer isn't necessarily factoring in the tps until warm? Either that or the sensor heats up and begins failing.

I seem to think it could be the tps. Any other ideas?

Click to expand...

Hello and good morning.

I have not seen that you have resolved the issue; vacuum lines can reek havoc on our Trucks. Replace ALL with rubber hose! You will be astonished at the difference that it will make and it is cheap! Run them ALL the way and do not just splice a piece here and there; 1/2 of a job may as well not even be started! Just a "pin hole" will cause erroneous diagnoses.

I get 20 MPG with 87 Unleaded with the "bloody ethanol" as long as I put in on cruise control and keep it at 55 MPH. This is AFTER replacing the Vacuum Lines!

Moreover, take the throttle cable assembly cover off and be sure that all cables are clean, free and lubricated.

It is the "little things" that reek havoc on the Trucks.

First though borrow or buy an Innova Code Reader off of Amazon. Be sure and determine if it is OBD II or I. It was $75 which includes the extension cable, Bad Back, so I can sit in the seat, and a Haynes Manual as well for translation.

This is ALL part of routine maintenance as they "do not repair themselves!"

Boon

Postscript: I know my limitations and I am NOT a mechanic just a Machinist and a Plumber. All of the aforementioned information comes from others, not me.

Yeah, i got it fixed, it was the TPS.

I pull good vacuum and i get about 22 mpg at 65 running 87 ethanol

I already have a code reader, but it showed nothing, my truck is OBD1, so the odds of it actually knowing whats wrong with it are about as good as the titanic's

wHAT IS:?

jebadiah04 said:

Yeah, i got it fixed, it was the TPS.

I pull good vacuum and i get about 22 mpg at 65 running 87 ethanol

I already have a code reader, but it showed nothing, my truck is OBD1, so the odds of it actually knowing whats wrong with it are about as good as the titanic's

Click to expand...

WHAT IS TPS "TIMMING POSITION SENSOR OR WHAT? THANKS

Throttle Position Sensor

yup throttle position sensor. have to take the butter flys off and its mounted underneath

I changed mine without removing the throttle body, kind of a PITA, but I got it done.