Intake Plenum (1 Viewer)

[Proven]

Okay, this is me coming out and saying that I was an idiot. I finally got my service manuals, but prior to them showing up I was a part swapping noob trying to get the PO 401 code to go away. So I bought a EGR valve and a Modulator (my old one was green, so I figger'd it was a good idea) only to find out that the EGR valve is spotless inside.

SO...Now that I have the FSM I noticed that I was retarded. I have now done some continuity checks and resistance checks...voltage checks on most of the things it calls for. Something that I found was carbon in the line going from the intake plenum to the EGR valve. So this would be an indicator that the VSV and some of the vacuum lines are plugged with that black death.

Here is where I need some advice:

1) How much of a pain in the arse is the plenum to take off? I was looking through the manual and the screws are upside down and not so accessible. Any tips/tricks to getting at some of these? My ABS is right there in the way of my elbow. I am thinking about a long extension from underneath, anyone tried this?

2) There isn't any cleaning procedures in the FSM for the VSV, is it servicable? What type of fluid is suggested for cleaning the upper intake and orifices?

3) How much time should I set aside for myself to do this? Just looking for a flatrate time that I can tell the girlfriend. I need her to know how long I will be unable to leave the truck for anything.

4) Was there anything that the FSM could have shown better or something that it didnt' show that well? (Something that I found frustrating was which hose to blow air down to verify flow through the VSV. There are two there.)


Just so you all know, I did do a search and while my jedi skills are growing each day they are still not that great with that technology.

EGR codes are going to be the end of me....HAHA

 

[RavenTai]

before you pull you intake off get a vac gauge and try to isolate exactly where in the vacuum system soemthing is going wrong,

you may just need to run a pipe cleaner through the pips that passes through the intake manifold

 

[ParadiseCruiser]

P -

For starters, I agree with Raven: make every effort to locate the bad part (or clogged lines) before taking anything apart.

>> How much of a pain in the arse is the plenum to take off?

Not necessary.

>> I am thinking about a long extension from underneath, anyone tried this?

If you need to replace the VSV, this is the way most of us do it.

This is a well documented issue. I would recommend spending an hour and reading through all of the older P0401 threads posted over the past couple of years on this forum. You will find all of the key problem areas, and solutions we have collectively found. It will be time well spent... no need to be frustrated.

Good luck with it.

Cheers, R -

 

[Rookie2]

>> I am thinking about a long extension from underneath, anyone tried this?

If you need to replace the VSV, this is the way we all do it.

I haven't done it this way, but instead removed the TB to get to the VSV. Since you can clean the TB once it's off... it's one of those two birds with one stone things. Once you've done it once, you'll find it's pretty easy to do.

:Beer:
Rookie2

 

[Proven]

Once the TB is off there is enough clearance to test the VSV?

I found one of my problems by diagnosing the outside of the issue. I had a clogged hose coming to the EGR from the VSV. The fitting on the plenum was clogged as well and I used a drill bit to clear it out (just turning it by my hand). So I am now suspecting that the vacuum lines under the plenum are also fouled.

This is a well documented issue. I would recommend spending an hour and reading through all of the older P0401 threads posted over the past couple of years on this forum. You will find all of the key problem areas, and solutions we have collectively found. It will be time well spent... no need to be frustrated

That is how I got this far. If it wasn't for the advice I had already gotten I might have actually taken this to a dealer. Instead I got the codes scanned at a auto parts store (then bought a scanner myself) and have been reading my FSM since it showed up. I decided that I should go under the plenum when I was pulling no vacuum at all to the EGR from the VSV side according to the FSM. I am just not looking forward to pulling that much of the intake apart.

 

[DTAYLOR]

Try the EGR ports in the intake

The EGR ports get stopped up pretty bad in these. Mine is the same, and being completely overhauled right now. When I took the intake off, I found the 1/2" EGR passage was completely stopped up. This was on the upper half, which took about an hour and a half of careful work to get off.

I too, drilled mine out in that one port, and I'm sure that will be stopped up on yours. I'm doing the complete overhaul (top and bottom) so I sent the intake halves with the head and block to the machine shop for a more thorough cleaning. Came nack like new.

I have also had many EGR code issues that turned on the ck engine light. The last time my inspection guy had to clean the EGR tube from the head to the valve itself. I am replacing the valve if I do not disable it all together.

Good luck!