It's been getting worse.

After a hard rain, the starter cranks, but the engine doesn't fire. It will crank repeatedly and once in a while, it will sputter as I'm shutting the key off.

When it doesn't start, I get spark from the coil wire and at the spark plug wires. I've checked for fuel pressure and I get 60+lbs when the key is turned on and it will drop back slowly to about 52lbs. Once, I got a code P0108-MAP voltage too high, but it went away after the truck started. If teh truck sits for awhile, i can get it to run if I crank the hell out of it and eventually, it will chug and smooth out and run fine. Once I get it started, it will start and stop fine.

I've replaced the ignition module, cap/rotor/wires/plugs, fuel pump and filter, MAP sensor. I've tried spraying Ether into the intake when it doesn't start. I've cleaned the MAF sensor with Electric contact cleaner. Nothing helped.

The past two days have been dry, but very humid and hot and I had the same problem. Any ideas??

Thanks in advance!

 

Check the base of the distributor for clogged vents....on the under side of the distributor there are supposed to be 2 vents to allow moisture out...these get clogged with debris and cause a moisture start condition...according to the GM TSB punch out the wire screens that are clogged and this is supposed to reduce condensation build up and hard start/no start/ rough idle....

 

Great suggestion! I'll try it and report back, here.

 

What year is your truck???
How many Miles on it???
What Brand of Cap, Rotor, Wires, Plugs, did youuse in it???
What did you gap the plugs at???

 

1997, 135,000 miles, Bosch wires and Duralast Cap/Rotor, Autolite plugs and I gapped the plugs at .045.

 

Duralast is kind of a Junkie Cap/Rotorfor this truck, should be AC Delco
You should be running ONLY AC Delco Platinum Plugs gapped at .060
I don't know too much about Bosch wires, I recommend Taylor Wires.
Good part's ain't Cheap, Cheap part's ain't good....
Good Luck.........

 

I agree, to some extent, with your opinion on less expensive parts.

In this case, I have been having the same, consistant problem leading me to believe that everything I've done so far hasn't had any affect on the real culprit.

I'll try the distributor vent suggestion and report back to everyone.

 

I punched out the vents and waited til it rained last nite. The truck didn't start this morning, no codes, and the same condition where it cranks, and cranks and only sputters once, when you are shutting the key off. Geez.

 

When you had the cap off how did the terminals look? Did they have a white residue on them? If so replace the cap and rotor.Huge problem with this style cap and rotor. Use only AcDelco, or Napa Mileage plus cap with Echlin rotor. Also unless you have a Ford motor in this Blazer put some AcDelco plugs in it, your engine will thank you.

 

The cap, rotor and wires are new, altho they are not AC Delco, maybe I'll try replacing them with Delco stuff.

Anyone ever have similar problems with the distributor pick-up as the culprit?