TPS mod = a pain in the A$$ and terrible gas mileage for me. Any suggestions?

[protomind]

About a week ago I replaced my fuel pressure regulator valve and solved some gas mileage issues I had been having, I started getting 20.2 mpg on the freeway up from 17ish. About a half a week ago I did the TPS mod and the truck seemed to run much better and smoother. I was very happy. Then I drove 250 miles. As soon as I got to the mountains the truck started running like **** and running rich. I got less then 15mpg. I went and bought a new TPS as I was on a vacation and didnt have all of my tools and the TPS mod was the only thing I had done since killer mileage. The truck started running alot better, but my mileage is back to 17.1. Why is my mileage terrible again?
Any ideas?

 

[protomind]

wrong forum?

 

[Blacksheep Josh]

did you reset the computer before the trip? which by reset i mean disconnecting the battery for a few minutes? this may be the issue. i go through the same thing each week, i barely use any gas at the beginning of the week and by the end i'm chugging through it.

it's ironic how the first generatinos are rated around 22 miles a gallon on teh highway... i wish.

 

[protomind]

Does it really need to be disconnected for a few minutes? I disconnected it for about a minute. I will go and try the few minute thing.

 

[Jeffbethandkidz]

I don't know if it would make any differance but the air is thinner at high altitudes, maybe that's why it ran rich. Maybe the baro reading didn't reset at the high altitudes so it thought is was still at a lower altitude and was fueling accordingly. I don't know, but it's a possibility. I think that the baro is infered by the maf sensor, so maybe check your maf for contamination. Next time I go back down to a lower altitude, I'm gonna check my baro and see if it is reseting because it runs a little warmer at lower altitude (lean?) and I'm curious if this could be related.

Did you disconnect the battery when you swapped tps sensors? Maybe if you did it helped to reset the baro, but I'm not sure why the milage would still be suffering unless you might need to reset the tps voltage on the new sensor, or maybe reset the baro now that your back home. Just suggestions, let us know what you find, as you have perked my interest.

 

[protomind]

Whats the 'baro'? At any rate the mountans are not that high at least nothing like the rockys I am talkn north carolna here, I am not sure how much that would affect things.

I unplugged the battery for a few seconds when I swapped the TPS, perhaps that was not long enough. Either way, the truck instantly stopped running rich after making the swap. At least I quit smelling gas and the mileage improved. Like I said though it did not get back to over 20mpg whch is where I was the tank before the before TPS mod.

Do you think that my fuel pressure regulator could go bad from running too rich for a short period of time? How lely is it that the TPS just got is slightly bad?

 

[protomind]

Anyone?

 

[protomind]

Well, I somehow fixed the problem by removing the electrical connector and jiggling the wires then reconnecting the sensor. Works great now. Mileage back to normal. Seems like I may have a slight short in the wire.