4.3 CPI Injector replacement pictures

[BlazerLT]

I believe those ports are for your EGR valve gas circulation and not your exhaust and that would explain the carbon buildup from a rich running engine. I wouldn't cause too much of a problem but it will be limiting the EGR gas going into the cylinders. No biggie but make sure you clean it out good. Been noticing any pinging lately?

Also, I notice that you have the wrong plug wires installed. Your should not be using 90 degree boots but straight boots on the cap end.

Overall, looks like you have had a leak for a while seeing the carbon buildup in the upper plenum.

How have was it to remove the lower intake?

[Cailen]

Ahhh yeah that makes sense on the EGR. I chipped it all out / vacuumed it up good.

This was done a while ago.. and you're right, the previous owner had vertical plugs on it, not horizontal ones. I noticed that about when I had that lower plenum off too.

And if you look at the last picture... about 10 beers hard. LOL

Seriously though, it took me 2 hours from unplugging sensors to lifting off the lower manifold and I could do it in about 20-30 minutes now. Putting it back together was another story.

The first time I put it back together I bolted it all down and had one bolt that wouldn't go in; had to take it all back apart. I took a die to the stubborn bolt cleaned it up, and I grabbed a thread cleaner from a friend: bad idea. The thread cleaner snapped off in the bolt hole. I had to drill out the center of the cleaner and use my dremel with a grinder to get the rest out, and then install a new heli coil.

Then I got it all bolted down and went to connect the inlet and return lines but they wouldn't go, so I had to unbolt it, fix the threads up on those and do it all again.

Then I put it back together AGAIN and when I started it up coolant pissed EVERYWHERE: didn't know I wasn't supposed to use rtv on the gasket surface. You should have seen how much coolant was in my oil. Couldn't have been good for my crankcase.

Anyway, now it's running alright. I had significant noise before and it's much quieter now. Little bit of a lope now though.

The second time I put it back t

[BlazerLT]

lol, sounds like you went through a lot, the beers probably didn't help though. hehehehe

Hope you used a torque wrench.

[93LT]

Mine smoothed up after good test drive, more so than the initial start up after completing the injector replacement.

Double check your vacuum lines for connections and cracks. If you grab your vacuum lines and your hand turns black, replace the vacuum line.

[BlazerLT]

Originally Posted by 93LT

Mine smoothed up after good test drive, more so than the initial start up after completing the injector replacement.

Double check your vacuum lines for connections and cracks. If you grab your vacuum lines and your hand turns black, replace the vacuum line.

Good point.

[BlazerLT]

Any update on this, I fund this thread really interesting.

[93LT]

Is your request addressed to me or Cailen? Or perhaps someone else?

I too find all that is involvedin this thread from other contributors rather interesting.

[Cailen]

Blackmarocraig probably... I'm quite interested in his problem too.

[BlazerLT]

Originally Posted by 93LT

Is your request addressed to me or Cailen? Or perhaps someone else?

I too find all that is involvedin this thread from other contributors rather interesting.

Both sets are awesome.

[Cailen]

I didn't think I had anything more to add, but I found another possible contributor to that nasty carbon buildup. It's obvious after today that since I've owned my truck the tstat has been stuck open. My temperature has never moved from about 50 or 60 C. It now definitely reaches operating temperature, and you can tell when the tstat opens (temp goes down 10 or so degrees).

I'm going to fill up tomorrow morning... looking forward to posting any increases in gas mileage I've noticed a steady increase in mpg every tank since I replaced the CPI and did my lower gasket (to the tune of about 7%).

Sadly, I am still not blowing very hot air out of my vents still. I did an acid flush along with the tstat change and additionally I removed the hoses from my heater core and flushed a LOT of water through it. Any suggestions would be appreciative.

[BlazerLT]

Make sure you burp the air out of the system and make sure the blending door is not jammed open.

[Cailen]

I'm working on burping it already... Added some fluid to the rad when I started her up this morning. There's a LOT of air in the system. When I took her for a test drive last night after I finished the needle would drop 50 or 60 degrees and then pop back up.

Thanks for the suggestion on the blending door, I'll check that.

[BlazerLT]

Originally Posted by Cailen

I'm working on burping it already... Added some fluid to the rad when I started her up this morning. There's a LOT of air in the system. When I took her for a test drive last night after I finished the needle would drop 50 or 60 degrees and then pop back up.

Thanks for the suggestion on the blending door, I'll check that.

Oh my, that is a lot of air still left.

Turn your heat to full hot and elevate the front of the truck on ramps and allow it to heat up until the stat opens and the level will drop as the air is displaced.

[Cailen]

Yeh I poured probably half a litre in this morning when I was ready to roll to work. Could have poured more in but I didn't have any premix left.

[Nagy]

Where did you get every part in the lower plenum? I seen new lines everywhere, and what the fuel injector sets in. Also, what did you use to seal the lower plenum to the upper? I am having probs just like the others, and this seems to be the ultimate fix.