92 454 throttle position sensor

[Larryzzo]

I have a 3500 1 ton with a 7.4 that doesn't want to stay running when it's cold. I was told to try a new TPS. Is it as simple of a change out as it looks, or are there any tricks to it?

[maxwedge]

More than likely that is not your problem, I would scan it and look for a coolant temp sensor that is faulty.

[1968 Pontiac]

Originally Posted by maxwedge

... look for a coolant temp sensor that is faulty.

I had the same problem with my 92. Bought the truck last December, but trouble didn't start to show until it got really cold in January. If I can simplify the function: the CTS acts like a choke on a carb when the engine is cold. You can also check the CTS with an ohm meter as there are specific resistance values for any given temperature. At 20 deg F mine was reading like it was a warm summer day, so the truck wouldn't start in January. Bought a new Delco CTS and averything was fine, sort of. Ocassionally the truck would run rough at idle, but wasn't throwing any codes so I changed the module, ignition coil, then TPS. All the old parts were original 92 parts and the truck ran better with every change. Now it runs perfect, and even gets half decent fuel mileage!! On SBC engines the CTS that you should be concerned about is near the thermostat housing, but I don't know where it is on the BBC as I've parked my 454 K3500 at another property. There's another CTS in the SBC head, but that one is for the temperature gauge.

[Larryzzo]

Sounds like the same problem. The truck runs great after it gets up to temp. I wont be driving the truck much this winter, but still want it fixed. I see there's a sending unit in each head. Are they both coolant temp. sensors? A new one is cheap enough ( about $14 ) so I'll change both, but I want to make sure I'm putting in the correct part. They look the same. Thanks for the info.

[2000CAYukon]

Looking at my factory manuals for 1990, it shows the Engine Coolant Temp Sensor in the intake manifold not the cylinder head. Things could have changed for 1992 but I doubt they moved the CTS.

//2000CAYukon

[J-Ri]

Agreed. It should be on the intake or the thermostat housing for any year. The one in the cylinder head is only for the temperature guage on the dash.