Hey Guys,

I own a 1995 Blazer, 4.3 L V-6. 132,000 miles. About a month ago I hoped in and drove about 4-5 blocks and parked and noticed the engine was surging, a few times it almost got to the point of dieing. So the following day I replaced all the spark plugs and wires, and it has been working fine since. Well now lately I've noticed once I get going about 40-45 mph I watch the tach and you can see as well as feel the engine rev up, not much but still noticable. I'm at a lose of what to do, in the last month it's got new spark plugs and wires, new oil return lines, new Catalytic Converter, seems like one thing after another. If anyone has any advice I'd really love to hear it. Thanks in advance.

 

Check fuel pressure and lines for leaks, might also be in the MAF sensor (dirty) needs cleaning.

 

Double check all the wires at the distributor cap. They have a tendency to pop out of the horizontal caps and lose good enough connection for a proper spark.

 

you might wanna check your egr valve also. it could be sticking just a little bit. this can cause some surging problems

 

Hey guys thanks for the advice it was rainy out today so the only thing I got checked was the wires and plugs everything is still hooked up good. After looking at that and test driving, the engine still surges. Tomorrow I'm going to look at the MAF sensor. Can I just clean that with a can of compressed air, or a Q-Tip with rubbing alcohol? And as far as the egr valve, I've never heard of it let alone know where I might find it, one of the guys I know here was looking at the car today and told me I might need to replace the PVC valve cause a little oil was getting back up out of it. Not really sure what that means, but I thought I'd throw it out there for your expert minds to decode. Thanks again in advance.

1995 Blazer
4.3 L V-6 132,000 miles
4 door, 4 WD

 

PCV valve = positive crankcase ventilation valve, it's purpose is to remove crankcase pressure, it's only a couple of bucks.

If your problem is happening at 40-45mph in "D", I'm thinking maybe a Trans problem with the torque converter clutch lock-up.
Try driving and duplicating the problem, when it occurs, shift to "3", maintain the same speed and see if the problem is still there or gone.

 

Ok so today I took a can of compressed air and cleaned the MAF Sensor, it looked like some dirt came off, so I put everything back together and went for a drive, the engine still surges but not as bad. I also found out that my transmission fluid was extremely low, so I've refilled that to see if that might make a difference. Thats all I've got done for now, I'm trying to spend the least amount of money to start out with, in case this might be something really bad.

 

Vacuum leak, dirty fuel filter, or dirty air filter.

 

I have a similar problem. 01 S10 4WD. After going into closed loop, the temp guage will drop to 0 -The engine starts to run crappy rpm's drop to 1000 - the temp guage jumps back up to running temp and the engine surges sometimes past 3000. This is getting dangerous! I have had it to my mech. no codes. He suspected the poppits in the spider that are on the expended warranty. Took it to the dealership - no codes. But they said the fuel pump was putting out low volume and wanted to charge 1200.00 to replace it. My son and I did the job and tested the old fuel pump - it was fine. Problem getting worse - engine dies and restarts hard - sometimes happens right off the bat - all the sensors check out fine - it's been tuned up regularly. My mechanic went back and checked the spark plugs, wires, cap & rotor. Transmission rebuilt at West Coast shortly before this started (sun-gear had failed. After rebuild a sensor had to be replaced that was installed failed) Ideas?