Engine stop in hot weather

SHERIDSMITH

MEMBER
1993 CHEVROLET S-10
4.3L
V6
2WD
AUTOMATIC
170,000 MILES

I have owned this truck for a year. It has always idled high. First repair was radiator and upper radiator hose. Then the serpentine belt which I was told is too wide and it squeals. Further on this problem of the engine stopping when it became 70 degrees or more outside began. They then changed my coil (twice), fuel pump, distributor rotor button, inline fuel filter, ignition module, and they said the coolant temperature sensor. Also my heat and air has stopped working.I need to add that when the engine stops due to hot weather it sputters when starting and can smell gas.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,740 POSTS

Welcome to 2CarPros.

You have already done a lot of work. Tell me, has fuel pressure been tested to make sure it is within the manufacturer's specs? If the regulator is bad, it will get too much fuel. Also, you indicated the coolant temperature sensor. Was it replaced?

There are actually two different coolant temperature sensors on this engine. One is for the gauge, and the other is for the computer. The one for the computer is how air/fuel ratios are determined.

Take a look at the two pictures I attached. The first one shows the one which controls air/fuel mixture. The second is for the gauge in the vehicle. I circled both. Note: The first pic has two circles. I just circled the number 6 because that is pointing to the sensor. Let me know which one was replaced.

Also, if you haven't checked fuel pressure, you really should do that even though the pump is new. Here is a link that shows how it is done. What I need you to pay attention to is fuel pressure drop off. If the pressure drops too quickly when the key is first turned off, that could indicate a leaking fuel injector. Also, under the link I attached the manufacturer's specs for fuel pressure.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Fuel Pressure

Ignition ON Engine OFF .................... 62-90 kPa (9-13 psi)

Now, if you have a live data scanner, here is what I suggest. Attach the scanner and when the engine is warmed up to operating temp, see what temperature the sensor is telling the computer the coolant is. If it is much colder than operating temperature, the computer will compensate by making the fuel mixture richer thinking it's cold.

Let me know what you find.

Joe

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