Question-------------------------
Followup To
Question -
Car will not start in damp or rainy weather. Will try to fire but not start. All logical parts have been replaced or looked at for this type of problem. Cold weather does not bother it.
Answer -
Hi Mel,
I don't even know what engine it has, much less what logical parts were checked.
I could guess, and start naming what I might think is logical.
First, I would need to know if there is spark. Good spark.
If there is, have you tried priming it, and will it fire then?
Send more info. Carb or Fuel injected? Distributor, or distributorless?
Van
Van, Thank you for your quick response. The Buick in question has a fuel injected engine and it has a coil pack not distributor. It has a 2.8L engine and is V6 MFI. It seems to have good spark. Logical parts replaced were spark plug wires, fuel pump, cable harness going to many parts. When the weather is dry starts with absolutely no problem. Please let me know if there is any further information that you need. Thank you for your help. Mel Gold
AnswerHi Mel,
If you have a good spark, then fuel would be the obvious next thing.
With that MFI, there is no way to see the actual spray, like you would with a TBI.
You said you replaced the fuel pump. Do you have a fuel pressure tester?
I would like a tester connected, and see if the pressure is correct.41 to 47 PSI is what my book shows that you should have.
Then some "noid" lights that connect to the injector connectors to see if pulses are taking place.
To further narrow it down to fuel, it would be nice to be able to introduce some gas or starting fluid during a no start incident. Might remove the pcv valve and pour a little gas into the hose, and replace it, and crank. See if it hits. If it does, then I would suspect low or no fuel pressure, or total lack of injector pulses. I would sincerely doubt that all the injectors were causing problems, but the injector control circuit could. Part of that system is voltage to the injectors, which is ignition voltage.
Then the ecm completes the circuit to ground for the appropriate injector, at the correct time.
There is an incredible amount of injector operating modes, determined by inputs from a variety of sensors.
One of the modes is a "clear flood" mode, where no fuel is allowed to enter the engine. That happens when the accelerator pedal is pressed against the floor during cranking. Make sure you are not pressing the pedal that far. And if the throttle position sensor happens to be sending a wide open throttle signal, due to moisture, it might do the same thing.
Now, that is just a guess of a possibility, but worth considering.
After verifying the fuel pressure, and using the noid lights to verify that there is no pulse to the injectors, I would probably see if it would start with the TPS disconnected.
I only assume that you have checked ALL the connections for moisture, spraying with WD40 to displace moisture.
There is also a barometric pressure sensor, and an intake air temperature sensor on that car, but as to weather they would prevent injection, I don't know, but I think they adjust the timing, which may be another place to consider.
Just thinking here now...does this problem happen even when the car is parked inside out of the direct rain? And with no rain or puddle splashing prior to the problem?
I am trying to think of where condensation would have that effect.
Doubt that I helped anything here, but sometimes brainstorming helps one think of something.
Van
