96 blazer 4.3 4wd

I have gone through pages and pages. I am clueless.
I have had a CEL for over a year now. I spent a lot of money and cant really spend another dollar because in a month I have to move 2,700 and can't afford that.
My Blazer when at a stop will bog out when I try to accelerate. If I am at a steady speed(while in D)is will cut out all the time. When in OD it does it less but I really just think that's because the RPM's are lower and I cant really hear/feel it. I have had it at the Lawrence Chevrolet Dealer I bought it from 6 years ago.
They did fuel tests and continuity tests on all the wires and said all they got was a "random cylinder misfire". I spent $248 there and got NOTHING actually done. Oh and now when driving straight the steering wheel is crooked due to the dealer. It's like they tweaked it or something.

Anyway. Then it was really bogging out so I took it to a small garage in town. They did pressure tests on it and said it was low fuel pressure. So the fuel pump was replaced,fuel filter,fuel pressure regulator and a section of fuel lines. It was still doing it. Then they said it was due to the cat being rotted out. So I replaced the whole exhaust with the magnaflo direct fit cat and muffler. That didn't fix it either. So recently I replaced the spider injectors and cleaned the throttle body and everything under the plenum since it was filthy. The injectors looked so bad. I also just today replaced the spark plugs with the AC Delco you all say to use. So I just took it for a spin and it still runs like crap. I am at a loss. I did get a CEL just now though. I have a friend on his way to tell me the code with his scan tool. I will update you on what it is. Last code was a Cylinder 6 misfire. Just wanted to see what you all thought first and then compare thoughts once the code was received.

 

Sounds like you've replaced A LOT of stuff that likely wasn't the source of the problem.

What are all of the codes, specifically, that you have received in the past throughout all of this work?

Have you cleaned the EGR valve? Tested the TPS sensor? Cleaned the MAF sensor?

 

Possible causes for the misfire of cylinder x is various sensors (i.e.; O2 sensor, MAP sensor, cam sensor, crank sensor, etc.), and vacuum hoses/valves (i.e.; PCV Valve, EGR valve). Make sure that all of the vacuum hoses are connected properly and are not deteriorated and leaking. A good way to tell if a vacuum hose is leaking, is to listen for a hissing noise while the engine is running.

If/When you get your new reading, if it is still a p030x code (x being the cylinder thats acting up or 0 for the random/multiple) then you should look into the sensors and vac lines/valves.

And like Swartikk said, you replaced a lot of things that probably didn't need replaced to begin with, blindly threw money at it hoping it would fix the problem. Not trying to be mean about it, but that's pretty much what you did.

RESEARCH is your friend, if you get a code saying cylinder x is misfiring, don't blondly replace your fuel system. Find out what causes the cylinder to misfire.. then troubleshoot it and since its full of sensors (which are pains in the ***) whenever a cylinder misfire is detected, it is not always (very rarely that i've seen) the fuel system causing it.

 

I just figured since the TRUSTY DEALER looked into the issue that everything was checked. They told me the bad cat could cause that but can not confirm it. They also said the cylinder 3 was way too reach and then would be too lean. The the pump quit on me during the tests. The fuel filter was blowing sludge(no joke...they couldn't even blow air through it). I had fuel sitting on top of the plenum. I have been floating all over this forum reading the articles and everything that was done seems like it could have been a cause or maybe a part of the problem.

We just ran the code. BANK 1 SENSOR

 

OBD2 codes have a letter followed by four numbers. What was the specific OBD2 code because there are more than 10 codes that deal with bank 1 sensors (there are 3 bank 1 sensors, but only one of them has anything to do with engine fuel delivery).

 

Trusty dealers aren't trusty.. they just want money for things they don't care about.

Told ya it was a sensor

But like the boss said, what was the specific code?

(ahh you beat me again boss :P)

 

Four total O2 sensors on the '96 - '97 trucks:

 

Sorry, but I doubt one bad O2 sensor would cause the issues he is having.

Does your buddy's scanner have the capability to do a live data stream? I would be interested in seeing if the timing is dropping back when the truck "Burps". Could this be the notoriuos timing chain tensioner vs knock sensor problem?

 

Kristoph30
Good vibes. Trying to think positive here and keeping things simple. I hope it is nothing major like that.

As far as the exact code goes. He is going to print it off for me to give me the full info. I believe it said B1S1. Looks like all the same part. I am hoping since I am not just getting a "random" reading that this will fix everything.

Thanks for the info guys.

 

well I re read the CEL today and got a P0420.