Hi everyone, I'm new around here. I hava a 95 Vortec Blazer and have a little problem.

After passing over a small water puddle. Engine compartment not getting wet at all so distributor and plug wires not the problem.

Any ideas?

TIA

 

I'm betting that you drove through 1000's of puddles in the last few months. Just the fact that there was a puddle means it had been raining. Open your hood on a morning that it has rained overnight and your whole engine comparment will be damp anyway. Check your cap / rotor / wires first. Look under your hood while the engine is running in the black of night and look for little arcing from wires or distributor cap. Pull a wire from cap and look for corrosion. Just happened to me so I speak from experience. Bad wires cause havoc with engine idle.

 

First have the computer read for DTC's to see if there are problems that the computer is checking on. This can help in finding out where to look for problems.

And after checking what Blasir talked about did not help you should check the base of the distributor for plugged drain holes. According to the service CD from GM there are two screens in the base of the distributor that are supposed to allow excessive moisture out the bottom. These get plugged after years and cause moisture to build up inside the cap. That moisture can cause performance issues ie rough idle etc.

Also check vacuum lines for cracks and breaks. The MAF sensor if it gets extremely dirty can cause a rough idle condition. It can be cleaned with CRC MAF Cleaner, it has to be removed from the air filter box lid and taken apart so the wires of the MAF are exposed to check and to clean. Extreme care must be taken with the MAF wires since the wires are thin and weak, spraying with cleaner should clean them but if the dirt/oil buildup is to bad you can take Q-tip(cotton swab) soaked with cleaner and lightly wipe the wires. If you break a wire then you will need to replace the MAF which can be expensive.

 

Interesting tips. However, I didn't provide a good enough explanation. No rain at all. Puddle was on a street in my neighborhood. One way street, only left tires (drivers) got wet so I think something underneeth got wet. After a little while, engine ran fine as usual, it hesitated just after passing puddle and for about 4 or 5 min. I guess until whatever was wet, dried.

I went thru the puddle again just to check it out and it happened again. No "Engine Service" present. Anyone with a similar situation?

 

It is possible but unlikely that the MAF got wet giving the computer wierd signals...now this might only be possible if the water made it into the airfilter...

My daughter had a boyfriend who was going to purchase a blazer and had it for the weekend, they took it out wheeling and got stuck in a water crossing when the water shorted out the MAF sensor...

 

20Blazer00, I think you nailed it but need to confirm after a test. I found out that the little tube/hose that goes from the air tube, after the filter case, to the driver's side valve cover was disconnected at the valve cover and laying/pointing down at the inner fender opening. Probably it was sucking water from there but not sure yet. I need to find a water puddle again and see what happens.

Thanks for all your suggestions