help...94 won't start when cold out.

[angela45356]

I have a 94 rodeo 4x4. When it's cold out it will not start. my husband has put plugs in it 2 time in one week and it will start but when it set over night the plugs load up with gas. Please if any one know what else we could do to get this thing running right. We've replaced o2 sencor and coolant tempature sencor and still no luck.

[Slade901]

Originally Posted by angela45356

I have a 94 rodeo 4x4. When it's cold out it will not start. my husband has put plugs in it 2 time in one week and it will start but when it set over night the plugs load up with gas. Please if any one know what else we could do to get this thing running right. We've replaced o2 sencor and coolant tempature sencor and still no luck.

I need clarification on "When it's cold out it will not start". Does the engine just spins and pins when you start it but would not stay running on its own? OR the engine will not spin or just slowly spin when you try to start it?
Engine that slowly spins or won't spin at all has a weak battery and needs to be replaced.

Gas with traces of water or clogged fuel injector will make the fuel harder to combust. Unburned fuel will find its way on the spark plugs, exhaust sensors, etc. I would try using a high fuel grade and use ISO-HEET water remover and fuel injector cleaner on a full gas tank.

[ibew595]

Idle air control valve? I just cleaned mine thinking it was bad and voilla thing didn't want to start. Once it was warmed up a little, it fired up fine.

[anthonyn]

Originally Posted by angela45356

I have a 94 rodeo 4x4. When it's cold out it will not start. my husband has put plugs in it 2 time in one week and it will start but when it set over night the plugs load up with gas. Please if any one know what else we could do to get this thing running right. We've replaced o2 sencor and coolant tempature sencor and still no luck.

If it won't start after sitting overnight and plugs load up with gas, then you may have a leaky fuel injector.

[angela45356]

It's not my battery because it will turn over fast. If it starts it turns back off. Fuel is getting to the plugs. We put dry gas in it for the water, incase it had water in gas. Didn't help. We then put cleaner in gas for injectors, it was cleaner called sea foam. We still have the problem. Once we clean the plugs, or we unplug the fuse for fuel pump and start it to clean the gas out of the plug area it will run for 3-4 days the it acts up again. Also once it runs it will surge with power for awhile.

[Slade901]

Does the exhaust comes out with black smoke? Black smoke means unburned fuel going to the exhaust system and it is getting burned there and so black smoke comes out.

More than likely, the Fuel Pressure Regulator diagphragm is leaking and the fuel is getting sucked into the intake manifold and flood the combustion area with excess fuel.

As you know the Fuel Pressure Regulator is controlled by a vacuum which is connected to a hose in the intake manifold. The diaphragm inside the Fuel Pressure Regulator acts like a valve which allows more or less fuel to the injectors. Once the diaphragm inside the Fuel Pressure Regulator is ruptured then excess fuel is getting into intake manifold and flood the engine and makes the engine harder to start.

Easy to spot if you have a ruptured diaphragm inside the Fuel Pressure Regulator is that to try to crank the engine or if the engine starts then disconnect the vacuum hose going to the diaphram inside the Fuel Pressure Regulator. If the vacuum hose has traces of fuel then you know the diaphragm has ruptured and needs to replace the whole Fuel Pressure Regulator.