GMC Repair: car hard to start, coolant temperature sensor, fuel pump relay

Question
hi.
i have a 1995 gmc jimmi two door 4 wheel drive 4.3 tuned port injection aprox. 95000 miles. when the vehicle is cold it starts very hard. after it has been driven it starts normal. i have to turn it over for about 30 seconds befor it starts when it's cold. then it runs rough for about another 30 seconds. then runs fine. it's had a recent tuneup. plugs, wires, cap, rotor, air cleaner. also new fuel tank, pump and filter. also replaced the EGR valve. it was staring hard like this befor the new parts. any help would be apreciated.
thankyou, john c. blanchard

Answer
You most likely have either:

1. A faulty fuel pump relay as the relay is used to run the fuel pump for 2 seconds upon first starting the vehicle to pressurize the fuel system.

2. A weak ignition coil(s)

3. a faulty IAC valve.

4. A faulty COLD start valve.(if applicable to your specific engine).

5. A coolant temperature sensor that is within specifications but is showing an OHM meter reading indicating an incorrect input to the computer thus causing the computer to believe that the engine is at or near normal operating temperature.

The above would be the most common.


However, What mechanical work or ANY kind of work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made as a vacuum line may have been knocked loose or a wire connection came loose, Look around in the area where work was performed.


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