99 jimmy hard to start (little gray box helps)

dont know why it does it but if its around 40 degrees f. and below it just wont start. it will crank but no start.well the last time i changed oiled i chould smell gas in the oil, so i changed the fuel pressure regulator. well that did fix the gas being in the oil. i did check the fuel pump pressure its right with the haynes book. bought a new battery clean all the connection but the ones on the starter. and still haveing problem.one thing that does help if i play with the wiring harnest that is located at the passenger side kick panel right by the door jam. there is a little gray box there if i shack the wires when i try to start it, it will start get to about 1grand ont the rpm then it dies. after doing about 3-5 times it start and stay running.what is this box. any input on this will be greatfull.

had the same problem, mine would not start below 30 degrees. Changed the fuel pump and filter, new batt. tried heating different componants in the morning. once i changed the coolant temp switch seems to be doing better. It starts now but not always on the first try.

dont know why it does it but if its around 40 degrees f. and below it just wont start. it will crank but no start.well the last time i changed oiled i chould smell gas in the oil, so i changed the fuel pressure regulator. well that did fix the gas being in the oil. i did check the fuel pump pressure its right with the haynes book. bought a new battery clean all the connection but the ones on the starter. and still haveing problem.one thing that does help if i play with the wiring harnest that is located at the passenger side kick panel right by the door jam. there is a little gray box there if i shack the wires when i try to start it, it will start get to about 1grand ont the rpm then it dies. after doing about 3-5 times it start and stay running.what is this box. any input on this will be greatfull.

How about doing a tuneup?

had the same problem, mine would not start below 30 degrees. Changed the fuel pump and filter, new batt. tried heating different componants in the morning. once i changed the coolant temp switch seems to be doing better. It starts now but not always on the first try.
would that be the coolant temp sending unit?

How about doing a tuneup?
been done fuel filter, spark plugs & wires, and air filter. i know its a good idea to change the distributor cap and rotor button on most cars. but this 99 jimmy dont know what do u think.

been done fuel filter, spark plugs & wires, and air filter. i know its a good idea to change the distributor cap and rotor button on most cars. but this 99 jimmy dont know what do u think.

You engine is just like any other.

Replace the cap and rotor.

The blazer isn't special.

would that be the coolant temp sending unit?


yes that's what i changed. not too hard . change when engine is cold and don't remove radiator cap. remember to seal threads on the new sensor. you shouldn't loose too much antifreeze, have some onhand to add.

Why is he changing it?

ill try both frist thing monday. hope it gets cold soon to see if those things work. will keep posted.thx

ill try both frist thing monday. hope it gets cold soon to see if those things work. will keep posted.thx

Hold on, don't start swapping stuff out like that.

A coolant temperature sensor will NOT cause a truck to not start up, PERIOD.

Hold on, don't start swapping stuff out like that.

A coolant temperature sensor will NOT cause a truck to not start up, PERIOD.
ok ok but a little gray box will make it start. then i guess that rules out cap and button.

Yes, replace the cap and rotor.

im willing to do anything to it.if i dont have to throw $100's at it.