I have a 93 S-10 Blazer 4x4 has a 4.3 W vin with a 4L60E tranny. I have done all the checks fuel pressure, leak down, plugs, wires, distributor, button, cat converter is cut off, and IT HAS NO CODES. Getting good blue spark, at plugs and pcv valve is good, iac is good, tps is good, map is good, not sure about M.A.F. THO. Will it make one act like it has no power and idle. Im to the point of thinking E.C.M. OR Doing a compression check. What is the valve on the center top of the plentum called? It is good. had a spare to check it with and it did same thing but not sure what it is called. Is the sensor in the breather tube critical? is that the air charge temp sensor? Thanks in advanced for any help. Missing terribly and when I take off it acts like the converter is stopped up but I eliminated it and does the same thing. SUPER ROUGH idle and no power and wants to stall out. Im bald and if I dont get this soon Im going to start pulling my chest hairs out. HELP PLEASE.

 

Take off and clean the EGR valve and put it back on with a new gasket that has the screen on it.

 

Thanks and Sorry, I did that too, its fine. Also the egr is closed at idle and its missing terrible at idle also. while I had it off I sealed it up and it still idled the same with the egr off and sealed. any other ideas? I was thinking the air charge sensor or coolant temp sensor. but it'll nickle and dime me to death changing it all out tho.

 

Our trucks do not have a M.A.F sensor, so you can rule that out.

What was the fuel pressure and leakdown readings?

 

yup Ours have what they call an air charge temp sensor in the breather tube was wandering what if any problems it could cause?

and the coolant temp sensor I been told and read it can make it run rich and miss and carry on

and mine is backfiring some times when I rev it up.

And the leak down test passed as I stated in the first post.

However, Since you asked I tell you what my secret numbers were. lol .

Was about 59 or 60 on KOEO. And leaked down to about 54 or 55 after about 10 minutes. also held about 58 to 60 while running.

Any one had a problem with the air charge or coolant temp sensor that sounds like my problem.

 

I've been told the coil to be good if giving good clean spark. (NICE AND BLUE and jumping good to ground) which it is.

Ignition control module in distributor should be good or not. (and not run rough just go out)

AND what the heck is the hockey puck looking valve in the center top of the plentum called??

 

The Puck on top is called the intake manifold tuning valve. Can this cause problems like I am having?

 

i had the same problem with mine and out of just a wth kinda move i checked the timing and saw that it was off a bunch...i discoed the timing bypass wire and it ran great to get me home, turned out it was my dist. the rivets holding in the magnet where craked all the way threw and it was throwing hell with the timing...replaced the dist and runs great again

 

Looking at mine it looks ok. Pick up looks good and control module looks good also. Borrowing a compression gauge tomorrow just to rule out compression. Thinking it's a timing issue tho cause I'm getting a lot of fuel out the pipe unburnt and backfire. Like too much fuel or not the correct spark to burn it. Guess it's time to borrow a timing light to just to see .

 

May even replace the new distributor cap with a new one just to see. It's bad when you have to replace new parts cause of the reputation new parts come with these days!