Engine/Transmission (1994 - 1998) overflow valve affect egts?

[MAleksandrowicz]

recently i have notice my egts getting worse and worse. i havent changed the overflow valve yet but i ordered one last week from pdr so i should have it any day now. i know that having a bad overflow valve will cause a drop in fuel economy which i have but how does it relate to the egts.

 

[Heepdriver]

I would think it would lessen them, reduce them. Less fuel pressure=Less fuel=Less EGT's. But do not know for sure. Maybe some one who know will tell us both.

Good luck, and have you cked your timing?

 

[biggy238]

Have you checked your air filter lately? It's been drier here causing more dust. The filters are clogging up more quickly than normal.



Air+Fuel=energy (egt)

more air and less fuel (bad overflow) = low egt

Less air and more fuel = high egt



If your OF valve is failing, putting a new one in will just add more fuel to the mix.

I think the reasoning behind the OF valve causing bad mileage is due to the lessened flow causing people to keep their foot in it longer to get the same results. Just my thoughts.

 

[tp0d]

Yep, dunno how but it happened to me. Before I messed with my OF valve, I would get 11-1200 with just the plate modded, wastegate blocked, 16° timing. Installed new valve, cant get it over 1000-1050 now. Truck is much more responsive also, of course...



bad mileage also yea. .



-j

 

[Heepdriver]

On the subject of the over flow valve, if running a fuel pressure gauge, can it be replaced with an adjustable valve of some sort? Could you do this if you ran an electric pusher pump, and if so of what volume (GPM) would the pump likely need to be? I happen to have a 140 GPM pump for a gasser and have thought of putting it on. I realize that you would have to adjust it high at idle to compensate for WOT fuel consumption.

 

[MAleksandrowicz]

air filter and timing were just done 2k miles ago. i talked to a friend of mine who said he had the same problem and when he changed his overflow valve his egts and mpg were improved. i really dont understand how this works but i guess it does. i guess i will find out when ever my overflow gets here.