bureau13

Quick question on the TPS: I hear an audible click as I rotate the spring-loaded plate mechanism (that attaches via a rod to the throttle cable) away from idle and back. However I don't think I'm hearing anything from the WOT switch in this test. Should I? And where in the travel should I hear it, if I should: Not all the way to the end, or is it? If so it might be obscured by the plate hitting the stop at the end of it's travel....

bureau13

I'll answer my own question: A better test is to check continuity between center pin (ground) and the other two pins, as you move the throttle. One side is grounded at idle, the other at WOT. I did that, it seems fine.

FredR

Jeff,

The idle switch contact is a micro switch and that is what you can hear clicking. The full throttle switch is a something that belongs in the Smithsonian and they are notably fickle in that the soldered joints fail. The full throttle switch seems to operate more or less at full throttle but even that is debatable as the butterfly is operated via a cam and thus the opening is non linear with respect to pedal movement [a good thing considering the gas flow characteristics of a butterfly throttle].

Rgds

Fred

bureau13

Interesting...I guess that explains the difference in audible click! I guess given the reliability issues you note, replacing the TPS at refresh time whether it needs it or not might be something to think about, but I think I'll roll the dice (this sets the wheels in motion such that my TPS will definitely fail within a week of putting everything back together, of course).

FredR

BTDT- when I migrated to Sharktuner I changed out the injectors for 30lb 4 hole Design 2 jobs. I figured that whilst I was at it I would pull the inlet manifold for a general inspection and replace a hose or two. First thing ST2 told me was that the full throttle switch did not seem to be working! At least I had a workaround option in ST2 as I told it to ignore the full throttle map and simply modified the cruise maps to do the same thing. Never made any sense to me as to why they should try to add extra fuel and timing based on a switched contact but they did.
Eventually I pulled the manifold [again] and changed out the TP switch but never changed the chip settings back to stock.

bureau13

Slight change of plans on my intake and oil filler tube refinish. My original plan was to strip the paint, use Alodine wipes (which I already bought) and then spray with primer, and high-temp paint. However, I was talking to a local guy who does a lot of work on 944s, and he has a local contact who powder coats all of his 944 valve covers, intakes, etc. He's been very happy with his work (I saw some, it did look good). He (the 944 guy) does do the blasting though, so he can make sure it's thoroughly cleaned.

I think I'm going to take my intake to his shop and use his blast cabinet, clean all the parts, and then have his powder coating guy do the final step. My question: Are the 928 intake bits different than the 944 bits in any relevant way? I know a lot of people talk about the alloys in our castings needing some special prep...should I use those Alodine wipes first? Or will he know how to do this if he already does 944 parts?

One thing I've noticed, as I peel off some of the paint that was already coming off: I get what looks like corrosion on the bare surface fairly rapidly. Since the powder coat guy will not be doing these "immediately" after they are blasted and cleaned, is there any other prep I need to do to stop this?

Anything else in general I need to do for this to work?

bureau13

I just reread Van's thread from when he found out his first engine was toast from the blast media, and now I'm terrified again. Pretty sure the guy here uses glass beads, which I think was the same thing used in Van's. Ugh.

However, I did pick up on something I had forgotten from that thread: Greg was saying how important it is to clean the intake plenums of all the oil that gets inside, as it tends to trap the blast media into a goop that doesn't want to come out.

I guess I know what I'm doing tomorrow...

bureau13

Anyone have a preferred clamp supplier? I'm not replating everything, so I'm not looking for the yellow cad look, really. Just thinking that if I'm refinishing the intake, and putting new hoses on it, my old clamps might stand out a bit too much for the wrong reasons.

bureau13

OK I just got my powder coated intake parts back, and they look pretty good. He masked off everything, so nothing could possibly have got in, right? Also, he masked off gasket surfaces, but there was some "overspray" (or whatever you would call it with this process) that got on some of the edges of the gasket surfaces, including on the oil fill tube. How critical is it that I sand that down? I'm betting this stuff isn't easy to get off...

Anyway, I blew some compressed air through there, nothing flew out. I then stuck a pressure cleaner nozzle in there and...holy crap, what is this stuff?

I'm getting a lot of grey residue in the water. Little flecks of stuff. If I just run hose pressure in there, I don't get much of anything, but that pressure washer is forcing something out. It doesn't feel gritty like blast media though. Maybe flecks of the old paint? When you guys clean it do you run high pressure water through it until it's clean? Or "regular pressure water?" If this is just flecks of the old finish, then it's probably not a problem, but I'm a little paranoid, with some of the stories being fresh in my mind...

Adk46

bureau13

I think you're right. That makes sense to me. I think I will make sure to clean them with as high a flow directly from the tap as possible, and be done. I don't think anything else would still be in there after all that pressure cleaning I did anyway.

bureau13

I really need to get better organized (he said for the thousandth time). I cannot find the little tube of VR Reinzosil that I got with my refresh parts ANYWHERE. I know it was there before, but I've clearly moved it somewhere for reasons unknown and simply cannot find it. I'll keep looking I guess, but...I have Dreibond, which I got for the oil filler tube. Can I use that for the water bridge instead of the Reinzosil? Or is that a terrible idea?

bureau13

I found a thread where Greg said he used Dreibond here, so I think I just answered my own question

Captain_Slow

I got some nice new clamps from Roger. One appears to be Cad plated the others look like stainless. All are same brand as originals. I think Porsche has moved away from Cad for environmental reasons.

bureau13

Thanks...I think maybe mine were not original...I soaked them overnight in some degreaser and then hosed them off...they seem to be stainless. They're not embarrassing anymore so I'll just reuse them, I think.