Hey guys,
Still having issues with my Blazer:
1988 Chevy Blazer S-10 4x4 4.3 TBI/EFI Z 203,000 Miles Rebuilt engine at 150,000 Rebuilt 700R4 trans at 197,000The story (summary from a previous post): The problem I had was a head gasket. So I pulled the intake, both heads (as well as all accessories up front) and replaced the gaskets. #5 cyl had the problem and was full of coolant. I put the heads back on, reinstalled the intake, everything else. Retimed it and had a code 33 (MAP Sensor). I would not idle, and had no power under load, I also heard a vacume leak. From the suggestions on these groups I retoqured the intake (as I didn't do it correctly the first time). That fixed the sound, code 33, and the idle (still a little rough) but still no power. It has power for the first minute or so at startup (while the SES light is on) but once that goes off, it's almost not enough to get it moving. I had replaced the MAP sensor, TBI gakset and EGR valve. I checked all my vacume lines, everything looked ok. Restarted, the code 33 came back, but no sound of a leak and it still idles (rough)
Today I spent 2 hours listening for a leak, checking lines, and just giving everything a good twice-over. It's running extremely rich, after all of this there is a nice black spot on the pavement ;) It seems it only has a black puff after I rev it and it's coming back down... so I assume it's loading up? The O2 sensor is probally shot at this point - but no code 13? Aside from that, when you start it, it has problems getting to idle, but after 3-5 seconds it gets there, and trips SES.
Now I have a code 33 and a 34. The book I have lists a 33, 34 as:
33: 1. Mass air flow (MAF) sensor - signal voltage or freq. is high during engine idle. 2. Manifold absolute pressure (MAP) sensor - signal voltage is high during engine idle. (Note: Engine missfire or unstable idle may cause this code) 34: 1. Mass air flow (MAF) sensor - signal voltage or freq. is high during engine idle. 2. Manifold absolute pressure (MAP) sensor - signal voltage is low during ignition on. 3. Pressure sensor circuit - signal voltage too high or low (carb. engines only)So, I thought that if I burned out the O2 sensor while trying to get it timed (forgot the tan wire), perhaps that is causing the rich condition, giving me a rough idle and tripping the 33.2. The idle isn't that rough, but it was before (plus many missfires ;)). However, I don't know what would be causing 34 -- aside from a MAF sensor... perhaps I should replace that too?
I guess I'll spend the $$ on a MAF and a O2 and see where that gets me, but I don't want to put in a 02 and cake it up with carbon it that won't help -- I rather replace that after.
At this point I'm almost ready to bring it to a shop -- OMG I HATE THAT. Partly the money, mostly the principal!
Before I do, I wanted to see what you guys thought.
Thanks, you guys have been a big help,
Joe