I have codes 34 and 44 and have tracked them to a vacuum issue, I think.

I have no vacuum pressure to my MAP sensor. The vacuum line goes into a wire loom about 4 inches from the MAP sensor then goes down between the engine block and the firewall. I can't see where the other end of the vacuum line goes to due to the wire loom and the tight space. can anyone shed some light on this. Maybe a picture of the line and where it connects to.

I already have the vacuum line diagram, I just need to see a picture of the line in the car.

 

No picture is necessary.

It goes to a nipple on the base of the carb that sticks out at an angle on the rear of the carb facing the dist, toward the pass side of the carb.

 

Just make sure you connect that vacuum line to the PROPER SENSOR. There are TWO on a computer controlled QJet engine and they look nearly identical. One is a VAC sensor (sort of like a MAP sensor, but reads vacuum rather than absolute pressure). The other is a very similar looking BARO sensor (reads outside barometric pressure and has NO hose on it whatsoever).

The VAC sensor line goes right where Sofa said.

 

The line on the sensor end is still connected. My sensor is on the drivers side. The line on the carb end has been eaten off by a mouse. I got it figured out now. I just need to figure out how to get the line replaced in the wire loom. The loom has a pretty good hold on the line and I'm afraid electrical tape will not hold the old and new lines together well enough to pull the new one through. I guess the line is 1/8 inch nylon.

 

Sounds about right.

You can go to Da Zohne and pick up a few feet of that stuff and acoupla the end thingies, and re-run it; doesn't just have to be enclosed in the wire split-loom, but just make it as neat and orderly as possible; or even, just jam a piece of rubber hose over the nipples. If memory serves though, the fittings on the 2 ends might be so different sized as to make that impractical.

 

I'm going to check through my scrap rubber vac lines and see if I have anything that will take up the gap in the nylon tube till I can get a new line from the parts store.

Is there a preferred replacement for the nylon tube?

 

Well, (duh) .... nylon. :klonk:

That said, it's not real critical, functionally. Over the years, for similar functions, various auto mfrs have used rubber hose, metal line, a combination of the 2, nylon, and probably other things as well, in addition to simply bolting the vacuum-measuring device directly within the source of vacuum (96-2000 5.7 fuel pressure regulator for example).

I suspect the factory used what they did in the case at hand purely out of manufacturing convenience. Allowed them to easily include it in that wiring harness, which (speaking strictly as a manufacturing engineer myself, at times) is a pretty elegant way of reducing parts / mfg steps / possibilities for error / etc.

 

The nylon line they used of that generation will just fall apart after several decades. Doesn't even need mice helping it out. The lines on my 78 Malibu made it to about 2001 and then the HVAC controls barely worked. I traced the line all the way back from under the dash to the engine and it was "crumbly" in some places (under the hood, not the stuff under the dash). If you bent it you could see a zillion cracks in it. I replaced it with factory-correct stuff and all was good again.

While you're in the wiring harness make sure the insulation on the wires hasn't suffered a similar fate. Back in the 80s the insulation was made with an additive derived from Soybeans. Mice would sniff it and their little brain would say "food". And they'd start gnawing on it.