Op, did you ever fix your lean codes issue? A couple people took the time to help you with it but you never got back, so I’m guessing you’ve been driving it like that for the past 5 years?

 

I ended up finding a sneaky vacuum leak that I overlooked after I had given up trying to fix that. When I figure this current issue out I'll be sure to keep the thread up to date

 

Ok, good luck

 

Very true. Sorry to jack your thread. Glad you found the vacuum. That and fuel volume would have been next guess. As for techs i wish i had some advice for you. As i have seen in the past you can usually tell the good techs by the quality of cars they are working on and they are not usually cheap. Unfortunately there are crooks out there that make us all look bad. If i was closer i would have loved to help you out. I hate hearing of techs taking advantage of people. I see it regularly.

 

Update: I talked to a mechanic friend who hooked up a computer and told me everything he can monitor looked fine. He went through a crank and cam relearn and it didn't help. He forgot to bring his fuel pressure tester but I told him the fuel pressure was within spec. He advised that the spider may be the issue (even though mine is the updated version that's only 5 years old). Here is what I found, to me the right side of the pictures looks suspiciously clean

 

I'm curious to see how this is resolved... my '94 CPI 4.3 idles fine until it (I think) goes into closed loop, then it picks up a noticeable random misfire. i haven't done any diagnostics on it yet...

 

I tested to make sure my EGR valve moves freely but I plan to run it without because everything inside was so dirty that there has to be a way too much exhaust is coming back into the intake, the bottom of my throttle body had a huge buildup of grease.

 

What a Thread, I am following... I am super curious how this turns out, please keep us posted and good luck 2 you

 

How did this work out? I have a 2000, which all of a sudden, just went to total crap, with misfires. I thought it was the coil, so went to buy a new one, but parts guy offered to check it with his own snap-on scanner. It showed no codes, so he drove it around 7rk blocks. As he kept on the throttle, it straighten out for a bit, but went back to crap. Now it threw codes for cam, and crank sensors. I made a stupid mistake, when trying to get the sensor out, leaving it loose, while blipping the engine, to turn over, to get slot on the reluctor plate into place, but the sensor jumped, and got pinched by the reluctor. Replaced senso, but not no hint of any spark. Put old one back in, same result, although with extensive cranking, it did fire just a bit, enough to keep the engine coughing over, like it was firing on only one cylinder. I was going to replace the new sensor, but haven't yet, figuring it is a waste of time. What I'm thinking is that the reluctor got shifted just enough to throw timing completely off, as it just pressed on to the distributor. Thinking of replacing the distributor. Any thoughts? Another mechanic suggested that it might be a failed distributor cap (Napa, 1 year old). He advised to only by GM electronic parts thru the dealer. Ugh....

 

Update: I was slow putting the upper intake back together because I didn't want to get water in there and it's been rainy in Western Washington. Pro tip: tighten the fuel lines all the way when putting the intake back together, seeing gas pour onto your exhaust pipes is a little scary. I got everything together and ran it with the EGR unplugged, the exhaust smelled like old car exhaust but the Blazer was not improved.

Back to square 1

I'm going to check fuel pressure again because at this point I think I'm losing my mind and it has to be suspect. The injectors seemed fine as I'd expect since they're the updated ones. Going a little insane trying to figure this out