Hey gang,

I came across a nice little "GOTCHA" this week.

I had noticed that I seemed to be a little sluggish on the low end. I also would once in a while stall when coming off of a partial throttle acceleration to idle position, as in making a turn or etc.

I was also getting some idle roughness. All these symptoms with the mileage led me to believe it was tune-up time. I did plugs and wires because of these symptoms and so I was thinking I had to go back and see what got missed.

I hadn't had the time to mess with it and told myself I probably needed new O2 sensors or sumthin, if it wasn't the tune-up.

This week I got a "Check Engine" light.


Well with a "Check Engine" on I knew it was time for a fix. I pulled the codes. IMRC Bank 1 and Bank 2 stuck open. I think they were 1367 and 1368 if I remember right.

That was a big surprise.

IMRC valves stuck open? Hmmmmm...Reach back and feel them moving freely, no problem...hmmmm. Checked connections. All tight.....Hmmmm. For those of you that know where these are located we are talking MAJOR Pain in the A** to get to.

Well I got to pondering some and started thinking vacuum. These run off of vacuum. I then traced the vacuum lines all the way back through the harness to the main manifold behind the battery. Well lookie here!!!!

Where the main manifold starts to tree off all the vacuum lines I pulled back the protective sheath to find that 3 of my 4 hoses had numerous tiny (1/16 to 1/8 of an inch maybe) holes in them making them resemble Swiss cheese. So I cut back the sheath and traced all the holes down far enough and spliced in new vacuum lines and Viola...everything works spiffy now. Idle is so smooth I forgot it was ever like that. No more check engine no more nothing.

It made perfect sense that IMRC was open, they need vacuum to close and as you lose vacuum, as in accelerating, they open up, as they should. The vacuum lines were not initially bad enough to be a complete failure, they would have been partially closed anyway. But finally the holes opened enough that they no longer had enough vacuum to close when they should.

The other 2 lines went out to EGR and ISC. At that point I didn't really care I just patched every line that had a hole. But the lines are color coded and you can trace them out to the final destination if you like. I just remember seeing where blue and white ended up going.

As to what caused the failure of the lines????

I can only guess that at some point some battery acid got down on the lines and ate through over time. I keep my engine area spotless but it could have happened with the previous owner. It is located directly behind the battery tray.

You guys might want to look it over when you get the chance. It is very easy to overlook and it is covered by the sheath. You will need to pull that back some to inspect. But you will be glad you did if you find holes like mine. Mine had numerous small holes that went about 4 inches down into the vacuum harness. It is amazing how those little leaks weren't enough to cause anything big for troubles, but it is REALLY amazing how much of an improvement it made in the basic functions of the engine when they aren't there.

I can only guess that it happens slowly over time as I never got a check engine light until last week. But it certainly made me appreciate just how critical a solid vacuum loop is.

Now it obviously is running happier and so is the owner....

 

TallTomG,
Good post.
I have the 97 model year and I have had to patch these vacume lines (behind the battery) twice now. Makes one hell of a difference in how the engine runs. I have never pulled back the protective harness and inspected the other lines but I will now.
Thanks for the heads up.

 

WLF,

Great looking truck. I also have the 97. I love what you've done for the frontend. Not too much, just enough to make it look different enough.

Like you I still lots of people comment.

How much did your front valance run?

 

TallTomG,
Do you mean the air dam? If so it was $75 plus shipping. I can give you a "url" for where I bought it if you want it.

I went and got the info
http://www.prestigious1.com/
It is in the air dams section model AD202
Cost $75 but shipping is higher then normal because it is fiberglass. Very good quality. Put Eagle Eyes 100mm superwhites in it.

 

Either of you two wouldn't happen to have a early model 97 would ya?
I'm looking for the early style clear cornors or early style euro diamond cornors. I had a vendor looking for a set but he says he can no longer find them. I would also consider swapping out the whole headlight and cornor assembly for a newer style if I knew everything would fit. Any help is apprecaited.

 

Hi KY,

Yes I have an early 97 and I got clear corners. I think mine came from ProParts out of California.

Hey I really like the looks of them but now I'm thinking WLF has gone a better route with his.

 

I got my early 97 corners at the online store on this vey site.

 

Thanks guys. Might go with the ones from the online store here even if I have to pay a little more. I have heard of a few complaints on Procarparts.com. Gotta wait till the next paycheck anyways, putting new Moog balljoints in tommorrow. Finally I will be able to grease part of the front end,