Ok, I have a 95 s-10 Blazer. This thing has developed a appetite for egr valves of recent. The last one I did by my self (afterwards I wondered why on earth I was paying the dealer so much) and I used a screened gasket to keep the carbon out of the valve. Well, shortly after that the truck started to idle rough. It feels exactly like the egr valve is open. The roughness only occurs at idle. The truck also stinks like it's running rich. The check engine light is on, but it's not setting a code. I checked the egr valve again last night and it was ok. No debris in it. The valve worked smoothly. I put it back together and the truck continued to run rough. I started to pull plug wires and found the #1 and #3 cylinders made no change in the idle. I pulled the plug on #1 and it was coal black, but not wet. I replaced the plug with a cheapie resistor core and started the truck. It ran a little smoother. I pulled both plug wires again and it still doesn't make a difference. I have yet to pull #3 because it's hard to get to. I figured on just replacing all the plugs this weekend. I know that I have a good spark at the distributor because the spark will jump 1/2" from the termial to the plug boot. I ran the truck for a while with the new #1 plug and then pulled it again. The plug was pitch black on one side, the other side was slightly dingy white. There was also a spot of wetness on the black side. What are you guys thinking?

Oh, the coolant reservoir is also empty. Don't read too much into that for the truck has always had a appetite for coolant. Never knew where it was going though.

May have bad news. I think that year S-10 had MAJOR problems with the fuel injection system. See if you can find a TSB on the net.
Gary

Yea, I know. We already replaced the spider manifold. Cleaned the injectors, replaced the regulator, the fuel pump (4 times!), egr (4 times)...


The mechanic wants to replace the injectors. I'm hoping to avoid the 1k bill.

Its the main fuel double hose going into the back of the plenum. It is leaking inside the plenum, I bet its rubbing on an edge. The plenum has a drain that floods #1 cyl to keep the plenum from filling up with fuel. It is a $50 part,,, takes less then 2 hours to fix by yourself.

Take the top of the plenum off and turn the key on to get the pump to cycle. You'll find the leak,,,,,,, P.S. STAND BACK !!!!!!!!

May have had some problems,,, but its the best running 4.3 ever. and our 94 S-10 Blazer that Cheryl uses for work still gets 20 mpg religiously at 135,000 miles !!!!

174,000 here. The truck took absolutly no repairs until 150k. Right then the fuel pumps started going out. It seems like everytime something breaks the repair is over 1 grand. If I had sold this truck several years ago for $0, I'd be money ahead.

Cord ... one simple test... check the compression on the cylinder with the sooty plug... if there isn't adequate compression... it won't burn the fuel properly and will soot up the plug... even if the mixture is correct and the injector isn't fouled... there just isn't enough heat because of the low compression... I like to eliminate the simple things first...

I agree with what was said above.
Also---
The '95 models were a split year. Early ones were still OBD I , while the later ones were OBD II. Which is yours? If you are not sure, you can tell by the way the ALDL plug under the dash looks. If it is rectangular, it is OBD I, if it is sort of rectangular with the corners cut off to form sort of a triangle, it is OBD II.
If it is OBD II, and, if the check engine light came on, there is a code stored.. What scanner are you using? You may not have a current code but there has to be codes in the history.. If the motor has or had a miss, I'll bet there is a code PO 300 stored..

Mine is definetly OBDII. I personally didn't down load the code, so I can only report what I was told: No code.

It's raining right now, but I want to get these plugs replaced. While I'm doing that I'll get a compression test done. With the milage on this engine, I'm not going to do a leak down-I already know that it'll fail. Suprising thing is that the engine isn't using much oil. You'd expect this 5w30 to be just blowing through it.

Although I have never used one myself. I believe that if you are using one of those cheapo code scanners, I don't think it will give you history codes. For this, you need a real scanner like a Tech 2 or a Snap-On.