boxburn

Hi all, this is more of a trying to understand the issue than fix it thread as outside of these few °C's, it'll start and run perfectly.

So when my overhead temp gauge is reading between 7-9°C and it is a cold start, sometimes the Jeep can turn over great but sputters quite a bit with varying throttle position until it fires up. For the first few seconds it continues to sputter then smooths out and it's perfect. Any ideas on what it may be?

gat

I would guess that a "tune up" would be the solution/answer. Clean the throttle body, replace the spark plugs, air filter, spark plugs wires, distributor cap and distributor rotor, pour a bottle of fuel injector cleaner in the fuel tank before you fill it next, and maybe drop a bit of water down the air intake when you have a hot soaked engine to clear out carbon in the cylinders.

boxburn

It will be due a service shortly so I'll probably replace everything as I did not do cap + arm, nor leads last time and it had been sat 7 years prior to that.

tjwalker

Along with completing the tuneup as discussed, an engine management sensor that can be in play here is the "coolant temperature sensor".

If the CTS is failing, it provides faulty data regarding temperature to the computer and the computer in kind will then make the necessary adjustments to the fuel/air ratio for what it thinks is the correct temperature. That can result in too lean or too rich of a fuel/air. Either of these conditions can lead to poor starts in certain temperatures.

These sensors can be tested; you can check them cold and hot and compare the resistance values measured to the factory chart for this sensor for a "ballpark" on if it's working. But it's an inexpensive sensor and if any questions, most folks just swap them out.

boxburn

I should have thought of that one.