A couple of weeks ago it rained really hard and my car would not start. The next day when it was dry it worked with no problems. This morning I go out after a heavy rain and again no start. I know that it is probably condensation or some form of moisture that is causing the problem. When this happens the engine cranks, but the fuel pump does not come on. Is the problem most likely in the fuel pump or main relay? How do I check to see what is getting wet? Could there be any other culprits?
Car not starting after heavy rain question
- Thread starter fionntan
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skimboard71104
New Member
Try the distributor cap. that same thing happened to mine and i bought a new cap with bolts and everything put it on and i haven't had a problem since.
I checked the distributor and it is dry as a bone. So is most of the engine bay. The thing that I notice is that the fuel pump does not turn on. I know tomorrow when it is dry and sunny it will start up. I just want to try and fix the problem before it happens next time. Is there any part of the fuel system from the main relay to the pump that is prone to water exposure?
skimboard71104
New Member
Honestly idk man that was what was wrong with mine if i were you i would check the whole fuel system.... like the fuel pressure service fitting, throttle body, IAC motor, fuel rail, fuel pressure regulator, distributor, air cleaner housing, fuse and relay control system. thats what i would do.
civichatch1988
Ef hatch
Check your grounds
civichatch1988
Ef hatch
Anything is possible when is comes to moisture and electroncis lol, your best bet would to be testing things with a multimeter when the car is doing this to check for loss of power anywhere. Basicly your gonna have to do process of elimitation weather you like it or not
The car is still not starting after two days of sun. I checked the main relay which checked out ok. I got a new one anyway and still nothing. I checked for voltage at the plug. Continuity was good on the black wire. Yel/Wht had 12.5 volts. Blk/Yel had 12.5. Blu/Wht only had 10.4 volts. Is 10.4 normal or should it be higher? I checked the fuel pump by jumping the plug and it comes on. The pump does not come on with the main relay connected. What else could it be?
civichatch1988
Ef hatch
I believe so, when key is on pos does the fuel pump kick on to charge the lines?
No when the key is on with the main relay plugged in then there is no action at the pump. If I remove the relay and jump the plug it comes on. I have the old relay that is good and I got a new one just to be safe and neither work. All the fuses are good. There is voltage at the relay plug. The blu/wht wire from the ignition is only reading 10.4 volts. The others read 12.5.
As well as your battery cables and connections. Just had this problem on my work van. Wouldn't start for a day because the battery connections were loose. It was odd because when all the accessories come on but it won't crank, you wouldn't think to check the battery. But it'll be the simplest thing to look at in your case.
I have checked the battery as well as the ground to the thermostat. I just checked the map sensor plug and the pink/wht wire had 2.8 volts and the yel/wht (I think) had 3.3 volts. I have read that I should have 5 volts to these wires. What does the voltage being low indicate? I can hear the main relay click when I turn the key to the on position.
civichatch1988
Ef hatch
this is beginning to sound like an issue i had once, don't quote me but my pump wouldn't come on either and when i ran direct power it would.. get an ecu pin out check for power at the wire where the fuel pump connects to the plug for the ecu. if no power trace it back. im petting on bad grounds or pump
When I jump the main relay plug the pump comes on so doesnt that mean that there is power getting to the pump? I am more concerned with the fact that there is less than 5 volts at the map sensor. I am going to start checking the ecu. I am really getting worried that the ecu has a short or something.
Ok so I went back through all the tests. Fuses are good. Relay is good. Pump is good. Map sensor shows .33 .28 volts, I was wrong before when is said 3.3 and 2.8. So I tested the ecu everything points toward a bad ecu. All the wires have voltage where needed and there is continuity in all the right places. I ran the trouble shooting flowcharts from the helms and they keep saying "substitute known good ecu". Will any p28 work or does it have to be one that has been chipped? What other ecu's could I use to test with?
