Mechanics

WET WEATHER STARTING

1999 Chevrolet Blazer • 170,000 miles

It seems every time I try to start the car cold during or after it has rained it cranks and cranks, sometimes sputtering and stumbling until it finally starts and runs normally afterward. It acts like it's not getting a spark due to moisture shorting out some ignition component, I have no idea how the moisture can reach the affected component when the hood is down and latched ! After the car does start there is no further incident even after multiple starts and stops. Unfortunately my car has to be out in all kinds of weather because I live in an apartment. The car is parked on a level paved lot. This started happening about 2 yrs ago in the winter usually after it has snowed. At first it would stumble, but start, but now it sometimes takes multiple tries before it does start. Thank you
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Balky Chevy
November 1, 2013.



I would tend to suspect the fuel pressure more but you have to do some testing before you are going to have any idea.

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.

Wrenchtech
Nov 1, 2013.