RKD in OKC

Don't forget to check the oil filler while you have the intake off!

docmirror

The knock sensors are a Pezio crystal type that puts out a pulse based on the specific harmonic of detonation (~5200Hz?). They have a good shielding program on the cable and that should remain intact if the wires are replaced. I don't know how the EZK interprets the signal from the sensor to determine if it is funtioning but not detonating. There may be a characteristic impedance that is sensed, or some other test done when they are strobed to determine operational state.

To take the injectors out, I simply spritzed some WD-40 down in the injector wells of the intake and let it sit for a day. Take off the fuel fittings at each end, and the 10mm nuts to the intake. then start prying carefully along the rail working it up as you go. Eventually it will pop off the intake and all the injectors and wiring will come up. Take the clips out of the top, then pry those damn Bosch connectors off the injector. Taking off the little metal wire bail is the worst part of the job, what a kludge.

worf928

If by little metal wire bail you mean the u-shaped spring steel clip that holds the female injector connector to the injector itself...

... then I really, really suggest that you do not remove them. On the older 928s (pre-90 IIRC) they are secured to the connector with a dab of melted plastic. Once you remove them they will never again stay on the connector, you'll loose at least one, and that injector connection will never be secure; it'll come off very easily and you'll wonder why your 928's running at 7/8ths.

If you cannot get the injector connectors loose with the fuel rails in place, then you can loosen the rails to get more finger room and then get the connectors off. Or get the rail off the top o-ring of the injectors and remove it completely.

The Bosch tool makes it easy or, if you don't have it, strong fingers will work.

In some cases the connectors will not come off with the tool or fingers. In that case judicious use of penetrant will help.

Bill51sdr

Dave, my '86 & '89 clips were/are "c" shaped, so to speak and reusable. I have seen Andy's '87 and his are the same, i.e. no plastic tab holding them in place. You just have to be careful about sending the clips flying if you attempt to remove them. I know some people, Bill Ball among others that just wiggle the connector as they are pulling on them in order to disconnect them.

perrys4

YIKES!!!

worf928

Ah. Good. And very interesting. I've seen a few 85-89 with "U"-shaped clips melted/tabbed in place on the connector.

EDIT: I just looked at an early-87 and sure enough, it has "C"-shaped clips. Maybe Porsche was experimenting with harness parts or different harness suppliers.

In any case, yes, the "C"-shaped clamps are not retained by a tab that breaks and can be removed and re-inserted.

Nevertheless, removing the clips is a PITA and I've never found it necessary. If fingers don't work and you don't have the Bosch tool, then remove the fuel rails to get more hand room. If that doesn't work, wiggle the injector out of the intake and then you can get a really good grip and/or use penetrant. The clips really don't do much.

On my '89, the POT (Previous Owner's Technician) put some sort of orange goo in the connector. POT probably thought it was a good idea, but the goo hardened into glue. Neither fingers nor Bosch tool worked, but with the rails out and injectors out, but still on the harness, I was able to use penetrant and by wiggling and some serious (but very harness-careful) tugging they came apart. Then I had to dental pick-out all the goo/glue.

Mongo

Parts ordered. Next Saturday is Party time.

Requests for beer anyone that is coming to lend a hand and/or learn something new?

There will be 2 24 packs there from Costco.... Newcastle, Heineken.... ?????

Bill Ball

Andy:

I recommend new knock sensors, manifold gaskets and most if not all of the breather hoses. The breather hose from the passenger side cam cover front fitting to the oil filler base almost always is in bad shape - soft, gooey and fragile - on older cars. The 3-way hose from the the oil filler neck (near the top) that joins up with the fuel vapor hose and heads down under the intake to the throttle housing is often bad as well. The fat hoses on the idle stabilizer are often OK.

When uncoupling the fuel injector plugs, watch those wire clips. They can fly off into space. Once you have the manifold unbolted, you need to unplug the ISV and throttle switch from the harness and the throttle cable needs to be popped off the throttle before you can remove it.

Also, observe the routing of the vacuum lines. Some follow convoluted paths to the actuators that you will need to replicate during reassembly.

Tape over the intake ports on the heads ASAP.

Watch the positioning of the breather hose that runs from the oil filler base back to the plastic Y on the throttle. When you put the manifold back on, it can get trapped against the throttle bellcrank and bind up the throttle. It needs to be located below the throttle. If you get it wrong, you will have to remove the manifold again to relocate it. So, once you get the manifold seated, test the throttle for free motion before you bolt everything down.

Note how the rear fuel dampner and pressure regulator brackets are held down by the rear-most manifold nuts and how they fit over the water jacket block-off plate bolt heads.

Note that the intake nuts are torqued to only 11 ft-lbs

Look at the crank position sensor. Its plug often disintegrates just like the knock sensor plug. That's one part that I found trashed on my car a while back. I carefully bound it back together for the time-being but I will replace it when I reinstall the SC.

I will try to make the party, but I think I have things already scheduled for that day.

ROG100

I am running a "SPECIAL" on the 87 to 90 Knock Sensors 911 606 141 00 $48.95 each.
PM or email me at Roger@ 928srus.com by tomorrow night to get em.

docmirror

Ok, melted clips. You have multiple choices, first you can clean the plastic and just dab a bit of the gel superglue back on it. Or, you can simply take a soldering gun, and when the clip is in place, touch the plastic housing over the split for the clip for a few seconds, it'll melt just fine.

The most important thing Bill said above is to tape over your intake ports immediatly after getting the intake off. Don't remove the tape until just before reinstalling the manifold. There ARE little sleeves that go on the studs, and you WILL drop at least on near the intake rner. If it goes in, you'll need a magnet and a lot of patience.

Bill51sdr

May I suggest you save the beer to celebrate once the job is done? Remember the 944 timing belt?

Mongo

Ok if I'm facing the engine looking at it from the front of the car, which cable is the throttle cable? The inner lower one or the outer lower one? It's been a while since I have taken these cables off to adjust them and forgot the orientation.

StratfordShark

Do you mean which cable on the bracket is the throttle cable?

Just trace the paths. The actual cable attached to throttle body snakes round pulley below air filter then disappears towards throttle body. The cable attached to gas pedal is attached to the other end of the bracket to which the 'direct' cable is attached.

It sounds more complicated to describe then it is to work out from looking at it!

FUSE69

Should be the inner lower cable.... but very easy to trace as StratfordShark points out....

Bill Ball

Inner lower ball.