I have a 1994 S-10 Blazer with the CPI engine. I know that the EGR valve needs to be replaced. Does the upper Plenum need to be removed to remove the EGR valve or can i remove the EGR without removing the upper plenum?

Also, the truck takes a long time to start, the engine turns over but does not start until several seconds later. Spark plugs, wires, coil, dist cap, all have been replaced. Is this caused by the EGR or is it another issue?

 

We recently had a discussion very similar to this. No, the upper plenum does not need to be removed, however you may find it a lot easier to get a 10mm swivel socket and using an extension and rachet with the swivel socket, it should come out fairly easily (recommended by lastcoupe). Also, there are gaskets with built in screens that do help in preventing carbon buildup in the valve.

You should attempt to clean the MAF sensor before you out-right replace it.

On the long startups... An EGR valve shouldn't really impact this, however, having low fuel pressure or a low battery could. If you turn the key to the RUN position and let it sit for atleast 10 seconds, does it start easier than if you just go immediately to START? Does it start easier after it has already been running? Is there any difference in the ease of starting it when the engine is hot vs. cold?

 

I also have a 94 blazer 4.3 "w" with TBI. After a couple hours of freeway driveing it lost power and wouldn't idle. I got to a garage and the mechanic said it was the EGR. He cleaned it and off we went running great until a couple hours later it started doing it again. I just know enough about engines to get me into trouble. I had doing about 75 mph so I slowed to 65 and removed the crankcase vent hose from the valve cover. My thinking was that the higher speed was causing blow by in the cylinder and this was clogging it. (this engine has 70,000 mi.) I also noticed that there was no suction at the PCV hose. It ran good for some time like this until a month ago it became increasingly hard to start.I used some starting fluid to try and get it started (I know I shouldn't)and it back fired and started.Now I see it has a lot of suction at the PCV valve. Is this suction normal? With a shot of starting fluid it starts,idles,and runs. It restarts fine up to a period 15 minutes. If I let it sit longer it won't. The fuel pump sounds normal. I dont have a pressure gauge to check the fuel pressure. Can I make one from a simple guage from the hardware store? Where is the regulator for the fuel.Are they expensive? I've also heard there is a bleed off valve to reduce fuel pressure when the motor is turned off. Is this part of the regultor or a seperate component?There is no parts store near where I live so I'll probably have to buy parts online so any help would be greatly appreciated. I love this vehicle and would hate to give up on it now. Thanks for your reply.