OPS relay mod

[CUCV]

It's amazing when you put a Delco t-stat (made in Mexico) next to a stant (made in China) and look at the difference. It ain't subtle.

 

[WarWagon]

Back on track - I put my Stant (yeah, I did it, too - once) 195* thermostat in a pot of water and boiled it, after Bill Heath suggested it when we changed it out for the ACDelco 195. The damn thing started late and only half-way opened by the time it was at 205 on my IR thermometer, and never opened much more than that by 212... I dunno HOW hot you would have to get it to open fully.

Use cooking oil to find the opening temperature if you really want to know.

Maybe the diesel t-stats are calibrated different than gas engines to be wide open before 10 degrees over the rating?

 

[buddy]

That picture is the LP relay, 94 and earlier did not have fuse center under the hood like later trucks. That relay controls LP only during cranking when the ignition is in START position. No need to touch that for the OPS relay mod.

The fuse to the left of the battery junction posts is the LP relay. Check out THIS THREAD for a lot of info on the fuel delivery. I posted particulars of OBDI trucks at the end.