JayPoorJay

Hello All.

Today I went in and changed the *fancy* plugs that I'd installed for the Bosch plugs I received from Roger. Things went as planned. Went to drive and there was trouble.

I started looking around and found a split in a hose... It's maybe 5/16s diameter soft rubber vacuum hose of sorts that runs up the passenger side of the engine bay along the side of the engine/cam cover/intake (where the split is) towards the front of the car,,, then across the front of the intake where it connects to a Tee past center line, more on the drivers side at the front of the engine... One side of the Tee connects to a hose that goes into the oil filler neck at the front of the engine, the other branch of the Tee connects a hose (all soft rubber approx 5/16ths) thatvtravels under the intake and disappears. For now, I took a strip of DUCT and sealed the split. Seems like a solution for the moment. Hmm. Yeah.

THE REAL PROBLEM - While following, moving and investigating this hose I noticed the plug you see in the picture. The hose basically goes/went right across the female end of this plug. It's just to the right/passenger side of the oil filler neck... Moving and messing around with the hose did male end of the plug IN... The male end of the plug basically disintegrated as the hose knocked into it. Then, on going to handle it, before I knew it, the whole thing fell apart. I have a feeling it goes to the idle stablizer, maybe? As it fell apart I heard a change in a hissing noise... I tried plugging it back in, making my best guess at it proper wire orientation... I'm not having luck. I plug it up, go to move her,,, and she just stalls. As I plugged the leads back in I heard changes in idle, air travel thru something under the intake and the way the engine runs. Unplugged, the idle kind of pulses or throbs - the HISS, noticeably louder and more pronounced. I'm in real trouble here, again, away from home and tools.

Q: what the hell now? Does anyone have a diagram or instruction on what is the proper plug in order color-wise? Open to any and all suggestions.

Deep BOW and thanks,,, in advance.





The plug assembly is captured by the frame/plug holder you can see empty in this photo...

To have better access to the wires i pulled the wire thru a space in the intakes plenum - it really goes under to be rightly plugged in.

SeanR

Call roger again and tell him you need a TPS harness. He’s got them in stock.

JayPoorJay

So that's what it is...! Thanks Sean!

Does the intake need to be removed to GET to it's other end for replacing? Is it a plug in at the TPS? I can do it,,, but not where I am. Don't have the right tools.

I hate to ask,,, but have to. Do you know the wire orientation by color?

928 at last

What year is your car?
I'll have a look and see what wiring diagrams I can find.....

JayPoorJay

A beautiful beautiful thing! MUCH appreciated

It's an 86...

928 at last

Don't celebrate yet...........

JayPoorJay

Lol,,,, well said

928 at last

Found an '86 diagram in my files....for some reason, can't get an image posted though, and, I'm not a good resource for reading these things...

But IF what I'm looking at is correct, the colour codes don't match up to what you've posted as a picture.

You're going to have to get someone who knows these to help out here. Sorry.

928 at last

Have you tried Sean through Facebook? (928 Docs)

Or Alan here on Rennlist? (He's the "go to" resource).....

928 at last

PM me your email and I'll send you a couple PDF files for your car.

JayPoorJay

So, as much as I have the disaster --- the plug that fell apart on me --- I figured out what was causing the problems with idle and the bouncing idle thru and after the spark plug change. There is a hose set that comes off of the drivers side intake plenum (see pic) that goes to the brake booster system in one direction and down and under the air intake via a steel section of tubing in the other. The steel tube wraps around the front of the intake, goes around and under the the area of the drivers side front fuel pressure regulator, continuing under the intake manifold connecting into a rubber tube that goes to where I HAVE NO THE HELL IDEA... When moving that section of vac tubing it appears that where the steel tube meets the rubber it sheared off completly creating the mother of all vacuum leaks... I couldnt see the damn thing.

I have no tools here with me. So, all I could do for now is shove the steel tubing into what remains of the rubber tubing under the plenum which had a serious positive effect onthe idle problem, which is good,,, but it will NOT hold. I have to remove the intake to make this repair and see what the heck else is going on under there.

With the wiring diagrams sent to me by members (THANK YOU) I think I was able to figure out the plug situation for now. I cant tell what going on on the TPS side of the plug. The Brown, White and White with the red strip side of things I could see BUT I dont know if the White (for instance) goes tot he yellow OR the blue on the TPS side. What a headache...


that combo set of vac tubes needed to be moved when changing plugs.

the steel tube that begins or ends with the 2 clamps and the rubber section on the right is the tubing that split off farther down the line and UNDER the intake plenum. What a PITA

Christopher Zach

You should be able to get to that vacuum line by removing the driver's side plenum, you don't have to remove the whole top end.

Still wondering why your spark plug shattered, did you switch them without taking the plenums off? I've heard it's possible but I just remove mine, and it's how I found that one of the rubber O connectors had folded under itself and made a nice little air leak....

GregBBRD

That male plug goes to the TPS and tells the computer if the car is at idle, cruise, or full throttle. It's a very short separate (NLA) wire, with a female plug on the other end.

Roger sells them, as do I.

GregBBRD

That's the vacuum source for the power brakes. It's a special reinforced hose, because it is exposed to full intake vacuum, which tries to suck it flat multiple times an hour.

The two problems are very common '85/'86 failure points. Looking around and replacing deteriorated parts, before trying to rely on a 32 year old car, is going to be a requirement.

JayPoorJay

Hey Chris, thanks Man... it wasnt the spark plug... It's the plug for (what I learned) is the TPS harness that shattered and fell apart. It was obvious in the moment that one of the spade end wire connectors had been out of the socket already,,, then, when I grabbed it to take a look, the whole thing fell apart.

PROBLEM (which remains) is that I lost track of what color wire was plugged into which socket. At this point I think I figured out that black and brown (in the center) are ground. The other 2,,, well,,, it's 50/50 at this point. I have them in,,, I just drove her home,,, and damn it, even with the steel hose just barely pushed into that rubber hose under the plenum/intake she's driving better than I remember from before. Crazy! Lol

And yes Mr. Brown, I will be needing a new wire harness. If you have an idea as to whether it the blue or the yellow that goes into that solid white wire,,, I'd be you friend for life,,, not that you want that, lol

I've some work ahead of me. I've already started removing the intake. I'll be needing some new injector seals/o-rings, maybe some new injectors as well. Although the injectors (even though they don't look pretty) seem to be doing ok.

And, damn good advice about removing the plenums... Damn good. It took some bending and twisting to remove and swap plugs, x2 or 3, in the end. I originally got a set of DENSO TT plugs or something and it ran poorly. I blamed the plugs (which it may have been also) but I now know it very well could have been plugs, the damn completely open and leaking sheared brake booster hose AND the disintergrated TPS connections... Damn, when it rains,,,,,,,,,!!!