1992 Blazer 4.3 S10 Rough idle cold

[Axlfromfinland]

Hi everyone!

I've got an "on- and off-going" problem with my '92 S10 Blazer.

Car specs:

Year 1992
Blazer S10 4.3 Tbi
4- doors 4WD
Mileage 200k miles

Symptoms:

As cold, every now and then it will start right up, but the idle is wery rough, and seems like its running on less than 6 cylinders. When giving gas, it revs up, but runs roughly and still seems to be running on less than 6. Won't stall though.

When engine warms up after a couple of minutes, the idle gets smooth and no issues what ever when driving.

So just to be clear, this issue is so far only happening when staring cold.


Parts (new off course) changed recently (less than 500miles on them):

Distributor
Spark plugs + wires
Alternator
Battery
IAC valve
Fuel filter

This symptom came up now and then before changing any parts.

Hope someone can help me with this issue! I am quite handy with cars (pure amateur though), but can't really afford solving the proble by changing loads of parts with no effect..

Thanks everyone and have a nice day!

Axl
Helsinki, Finland

[rhandwor]

Originally Posted by Axlfromfinland

Hi everyone!

I've got an "on- and off-going" problem with my '92 S10 Blazer.

Car specs:

Year 1992
Blazer S10 4.3 Tbi
4- doors 4WD
Mileage 200k miles

Symptoms:

As cold, every now and then it will start right up, but the idle is wery rough, and seems like its running on less than 6 cylinders. When giving gas, it revs up, but runs roughly and still seems to be running on less than 6. Won't stall though.

When engine warms up after a couple of minutes, the idle gets smooth and no issues what ever when driving.

So just to be clear, this issue is so far only happening when staring cold.


Parts (new off course) changed recently (less than 500miles on them):

Distributor
Spark plugs + wires
Alternator
Battery
IAC valve
Fuel filter

This symptom came up now and then before changing any parts.

Hope someone can help me with this issue! I am quite handy with cars (pure amateur though), but can't really afford solving the proble by changing loads of parts with no effect..

Thanks everyone and have a nice day!

Axl
Helsinki, Finland

Use an ohm meter and ohm the two wire temperature sensor. Post reading and temperature when cold.

[Axlfromfinland]

Thanks "rhandwor" for the tip! Will test it by end of the week and post what the readings were.

[Axlfromfinland]

Replaced temp sensor today (2- wire, beside upper coolant hose in front of engine) -> no change in symptoms. Still rough idle cold.. Any ideas where to continue?

Thanks!

[rhandwor]

Originally Posted by Axlfromfinland

Replaced temp sensor today (2- wire, beside upper coolant hose in front of engine) -> no change in symptoms. Still rough idle cold.. Any ideas where to continue?

Thanks!

Check ground wires near thermostat housing,left rear of engine. Check for leaking vacuum hoses,spray WD 40 along intake,around throttle body. You can get some cleaner and clean IAC. Idle Air Control Valve. You can also put a can of injector cleaner in the fuel tank. Try spraying a little starting fluid around the two injectors I think the engine is running lean until it warms up.