Sorry if all these are out of order or if I posted too many of them or double posted them I apologize.












Ok so heres where im at. I just installedA 4.3 reman motor in my 1999 2 dr ,2wd
Blazer. Old motor had 167k miles on it b4 i deep 6d it. I learned the wonderful lesson of not to throw away about 1500$ rebuilding the top end of the 4.3 cuz soon enough the bottom end shall fail.. ( as in rod knockin). So another 2300$ on my reman from LKQ and im back on the road. But not really pleased with the avenue i traveled to get here. 2 shady tree mechanics and all the labor money later i would have been bettr off just taking it to the reputable dealership . It would have been more expensive but at least i would not still be dealing with the headaches that I am today. After all said and done I'm still troubleshooting myself. The blazer has no pwr whatsoever. Push gas , bogs down. Like its out of time by one notch or it can't breathe it seems like. I've got some kind of evap hose broken off of something on the upper intake plenum. I've still got three black wires behind the motor where I do not know where they go. I did the upgrade to the multi-port fuel injection spider still get terrible mileage and no power. I'm very disgusted at how all of this has turned out I'm ready to just strike a freaking match to it. I feel like this whole situation has broken me, chewed me up and spit me into the fiery pits of purgatory. Completely defeated to say the least... At this time im throwing a few codes, blazer runs like crap on acceleration. Cranks , starts and idles fine. Im going to include some LIVE DATA readings and list the codes im throwing... If anyone has any knowleadge or experience they would like to share with me that would be nice. Very much appreciated. I have read and read and read for the past 2 days on the forums. Seems my mind is just sputtering. Overwhelmed and defeated. So I'm operating in slow motion going to take one thing at a time and try to get to the bottom of everything. Thanks for all that you guys do for the people like me in need of some direction...thank you.
My codes are p0405, p0420 ,p0452
If you look at my past post you can see how long this has been dragging on what started out as a weekend ordeal and turned into months I'm so over it. Thank you in advance for any insight that you can give... Thank you for your time.
Have a good day and God bless.

 

Im guessing the black wires are the grounds that attach to the back of the passenger head. Something difficult to attach with the engine in all the way. This could be the root of all the problems you are experiencing since these are major ground points. Need photo of this and the broken off hose.

 

 

Oh man. You sound spent. I feel for you.

I'd try to wait for a bit and come back at it with a fresh look. Look for the basics like above with the grounds.

 

Take a deep breath, we can fix this but its a methodical one step at a time situation. I'll stick with you until this is fixed if you have the energy and want the help.

The comments about the grounds is good advice, this can cause all manner of issues. If that does not get you right:

None of your codes use sensors with a frame ground, so:

P0452 is an evap pressure sensor low output. This can be the sensor, its power or its ground but it can also be a vacuum leak somewhere in the evap system. This won't cause the engine to run lousy unless there is a problem with the purge control valve and its not closed and sealed for normal operation as it should be because this would cause a vacuum leak. A quick check would be to plug the output of the purge valve to see if that improves anything. A vacuum leak anywhere else can cause problems so get your fuel trims at idle and 2500 rpms to help diagnose a vacuum leak and see if you can rotate your scanner screen shots. Your trims are marginally high not catastrophic but they do show adding fuel for a perceived lean condition. This can be vacuum leak which will get better trims at 2500rpm but it could also be injectors, unmetered air, etc.

P0420 is a cat problem. This may have no effect on how the engine runs unless there is a problem with the O2 sensors, their power or wiring or the cat is plugged and causing excessing back pressure. We need to see the o2 sensors graphed at operating temperature to see what's going on.

P0405 is the EGR valve. This can also cause problems, do you know if its working correctly?

You have posted multiple sensor values. Check MAP, IAT, ECT on a cold engine and compare the values to ambient. Check the ECT at operating temp, I saw a value that looked low. Watch your TPS sensor with engine off key on while putting the gas pedal slowly through the entire travel and make sure that the end values make sense with no glitches in the output. Get your MAF at idle which is a crude check and a start. Full load testing is required to really test the MAF properly but that can be later.

George

 

I'm most definitely willing to put in the time to get the blazer running correctly. I have been at it strong for the past 3 months. I appreciate all the information that you guys and gals have given me. I am at Whit's end with this damn blazer it is my daily driver so I can't give up on it like everybody in my family wants me to because they're tired of hearing about it too. So I just keep all the information to myself and do it by myself slowly one problem at a time with you guys's help if possible. I mean this thing has really wore me down. I'm going to post a picture where I think this may be one vacuum leak that I've got on top of the intake manifold plenum I will post a picture. As far as the catalytic converter goes I do not have one so that would be the grounds for the 405 code. I was thinking of doing an EGR delete on my motor but wouldn't that be the same thing as just unplugging the EGR valve electrical connector? Would that help in performance? The fuel tank pressure sensor connector voltage low has been a code thrown since day one since I've had it I'm just not too keen into dropping the gas tank again but I know that I'm going to have to to fix the issue. I've got a brand new mass air flow . But I do have a k&n air filter on my intake that takes oil that could have gotten the maf sensor dirty. The idle air control and the PCV I will be looking into today as well as trying to get you some more readouts on my fuel trims at idle and 2500 RPMs my scanner is doing something weird. Whenever I plug it into the port it was just showing a blank screen. If I keep it plugged in for it a few minutes it comes on. It also takes batteries which I suppose is where you can keep live data stored in memory. I'm not real familiar with reading the outputs of the live data but I know what some of it is but I don't really know what the usual parameters are for everything running. But we can get to that later I appreciate all your help and I'll get back to you soon with some more information thank youPictures to follow.....
Ps. If you look at my post about mystery wires I posted some pictures of the wires in that post I think there's three photos thanks

 

Isn't there some kind of a vacuum hose that's supposed to be on here with this connector that's looks to be broke off. Would cause and vacuum leak correct?

 

Live data is what your doing when you display the sensor values like in the previous post. O2 sensor graphing looks like this:




George

 

Yours looks ok as long as it has the connection at the bottom that runs back towards the distributor. There should be a white clip holding the line in place but mine broke. Also has a green Evap service port cap a few inches down the plastic line.

 

Found prob... But still need to know the best way to clean my gas tank. Seems the problem was nothing but needing a fuel filter change because when I pulled that fuel filter off you should have seen the black/rusty gasoline that was coming out of it. I changed that fuel filter probably about 12,000 mi ago and that was the condition it was in. Blazer had more power was running better everything was all around better after the fuel filter change. But my dilemma is I need to find something that works to clean the gas tank with. When I first got the blazer that's the first thing I did was drop the tank got the old nasty gas out and pressure washed the tank as best I could but I could not reach the ceiling of the tank due to its location it just wasn't humanly possible. So if anybody has any suggestions on how to clean the rust off the ceiling of the tank and get all the rust out please let me know. I have some muriatic acid I don't know if that would work or if it would deplete the integrity of the tank. Thanks in advance