94 S-10 blazer problems

I have read through most of the problems that I am having, and I still have a few questions.

My 94 S-10 Blazer with 4.3L Vortec is still having problems. Several moths ago, I took apart the intake manifold and had it cleaned, replaced the gaskets and the "nuts" into the CPI wich had a hole in one part.

When the problems first occured, it would run fine when it was cold, but as it warmed up to operating temp, it would just die. With the help of some starting fluid, it would start again and run at a high RPMs, but would die at low RPMs. I have replaced the fuel filter, fuel pump, and sending unit so far with the same problems. I took off the EGR valve, cleaned it, and replaced it with a new gasket. The engine ran great for about a day, then the problems started again. I have ordered a new CPI to replace the old one, and I would like to know if that may solve my problems. Any feedback would be great so I can stop replacing everthing!!

I would pull your EGR again first before replacing your CPI, and check for carbon chunks. Make should that the plunger moves freely and closes all the way. Clean it with some carb. cleaner and reinstall it with a new casket. See if that works first.

I would pull your EGR again first before replacing your CPI, and check for carbon chunks. Make should that the plunger moves freely and closes all the way. Clean it with some carb. cleaner and reinstall it with a new casket. See if that works first.


That seemed to do the trick for now. Is there anything I can do to prevent the carbon build up inside the EGR valve? I have read through the acetone threads and I decided to give it a try. It seems to be working in the scence that the valve has not stuck yet. Any input would be wonderful!

I've had trouble with the EGR Valve plugging up with carbon on my "94". My wife use to drive it only to the store and back. If lucky, 2 miles a week. Then I got my wife a "96" Blazer and took the "94" for my self. I had to open it up about 4 times to clean out the carbon. I switch over to 92 octane gas and I drive it everyday to work about 45 miles round trip at around 60 - 65 MPH and no problems. The only thing that I can think of is if the motor doesn't get a chance to run at normal operating temp. for long periods and the RPM's are always low. You will get carbon build up in your motor. You need to get out there and run. I've heard of some guys using Seafoam cleaner on there intakes, but I haven't tried it. Motor been running carbon free for 3 years now, and I see no traces of build up. My son uses Amsoil in his gas on his "97" P/U and never had a carbon build up at all. In fact I changed his CPI and the ports for the EGR were clear. So take your pick. I believe that it has a lot to do with the weather environment and altitude that everyone has to deal with. Here, we don’t have to deal with the extreme cold, just the heat sometimes.

Well, after breaking down and spending the money, I replaced the CPI. This solved all my issues. When I pulled the old one out, the tubes where leaking and unburned fuel was leaking out. After the replacment, my fuel milage is better, much more power and it just all in all runs so much better. Hopefully it will last another couple hundred thousand miles!!

scott, this thread is almost 2 years old. please refrain from posting in older threads :nono: