Q: Why is my minivan difficult to start when the engine is warm, but not when it is cold?

asked by on October 27, 2016

I recently had trouble starting my car and as a result had the fuel pump changed. After about a week, I began having trouble starting the car once I had driven it, and the engine is warmed up. It turns over, and after a few times of trying to start it, it will eventually start, but sounds like it might stall when this is happening, then no problem driving after that. It starts just fine when it is cooled down. No odd smells or issues of the vehicle stalling. 6 months ago the van had stalled at an intersection, and the CAM sensor was replaced. No problems until the fuel pump died. I haven't tried changing out O2 sensor or MAP sensor or anything yet.

My car has 140500 miles.
My car has an automatic transmission.

Hey there. There are a couple of reasons why this could be happening. I have seen a faulty coolant temperature sensor cause this problem on warm start up. There also could be a problem with the crankshaft position sensor not reading properly and causing a hard start. I have also seen fouled spark plugs cause this issue as well. The spark plugs could be fouled from the hard starting issue you had before you put the new fuel pump in. The oxygen sensor will not cause your car not to start if it has gone bad. I suggest having a certified technician from YourMechanic come and diagnose this hard start in person so that the right repair can be performed.

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