on rainy days my 99 Tahoe won't start.the next dry day starts right up.

Humidity can get in to the distributor,and cause cranking problem,s,check the distributor,for moisture.

Sounds like old ignition wiring. They have a graphite/carbon core and when the rubber gets old it gets a tad porous and the moisture just fouls it up.

disttibuter,plug wires,might has well change the pugs also.

thanks for the answers fellows.yep,i thought of all those distributor,plugs etc.its a daily driven not many miles.i changed dist cap,rotor,wires,and plugs less than 3yrs ago. I guess i'll have to change it out.

I have a 1997 Tahoe with a 5.7 vortec. When it was raining or damp outside the thing wouldn't start. I checked the fuel pressure new distributer rotor and cap, and nothing worked. still no start when it was damp. I found the problem by accident and hope it helps someone else with the same issues. I tried everything I could think of so I decided to change the cam sensor on the the distributor. I twisted the mounting screw off and ruined the distributor. I was inspecting the distributor after removing it and noticed the distributor housing was plastic, and the rotor was rubbing on the crank sensor. apparently the plastic distributor isn't mean't to last but 160,000 mi or so. I went to Auto Zone and purchased a new distributor for $165.00. Took it home and installed it and the Tahoe fired right up. It has not failed one time to start sinse changing the distributor. I about pulled my hair out trying to find the problem, and it was a worn out distributor.

you will need to get your timing set after installing a new distributor, it has be put on a scanner and set with engine idle at 1000 rpm.My mechanic charged 45.00 to ste the timing. now my Tahoe runs like a top.

it is not plugs /wires /cap/rotor/or coil..so don't wast your time..i have done them all..how ever I will agree that the distributor.a new one will cure your issue

I got 1999 Tahoe.. It won't start after it rained sitting over night...I changed plug wires and it start right up..Distributor cap didn't have any moisture inside..their was just some corrosion on contacts inside the cap..scraped contacts clean.

The distributor is plastic, after about 100,000 miles they wear out. My 99 Tahoe had the no start when damp problem. I put a new distributor in it and it fixed the problem. It now starts everytime.