Where to look next? Feedback/advice?

[spacecad3t]

It's funny because the car actually idled fine when I got it, but I could tell it was adjusted to do so, from the original condition of hoses. Everything was dry, split, etc. Spray testing was immediately obvious and when I my local inspection shop smog it, it also failed.

But, as I replaced things, the tune started to go wild and there was a moment before I swapped the AFM and O2 sensor (likely original) that it was running at its worst.

My dumb assumption here was that the idle stop was correctly set. I had set it too, after replacing the broken set screw. I used a paper gauge, but must have over tightened it. I see now, watching the timing light that a minuscule amount will push the rpm 100-200rpm.

[spacecad3t]

I may have spoke too soon. I may just need to swap my TPS this weekend to see...

Went out this morning to test the idling/cold start as it's 40 out. I was able back the bypass screw out more than a 1/4 yesterday and so it started very well today, no vibration, good revs at cold temps. Idling perfectly.

Let it warm up to just below the first tick on the temp gauge and the performed a recheck of the base idle following clarks. I jumpered the ICV, and was able to hit 850-900rpm with the same 1/4-ish out on the bypass.

Then, car moves beyond the first tick into the middle of the temp gauge, and idle creeps up to 1100... Try closing the bypass, maybe 1050, fully closed.

Sanity checked the throttle stop, cable, and TPS function, all not impacting idle.

Im thinking at this point I got to have an electrical gremlin or some very hot throttle/TPS issue.

[spacecad3t]

aaaaand, I think I striped the manifold

I put the slightest amount of torque at the end of handing tightening but now it wont seal and I have at least 1 throttle body bolt that spins.

Any advice here? About to AAA it to my guy...

[spacecad3t]

Couple of questions:

Unfortunately, I didn't know 1 of the throttle body bolts is longer than the rest. Does it need to return to the same hole?
When I look online, like here: https://www.autoatlanta.com/porsche-par ... ion=107-00
I only see 1 type listed: pan-head screw m 6 x 25

For the price of manifolds on ebay vs. a M6 timesert kit, is it worth going the timesert route? It will make them stronger, but then again- I should not need to remove it very often.

What are the torque specs for these? I didn't see that on Clarks, or other references.

[O875]

I can't find those specific bolts anywhere but there is a general comment of "all other" in the technical specifications booklet M6 8 + 2 Nm (6 + 1) ftlb

[Tom]

I believe all the throttle body bolts should be the same length, as PET shows. One of your may have been too long, so it bottomed out and stripped the threads. A heli-coil is more than enough for those threads -- stronger than the original. Lots of people push for Timeserts, which are great, but heli-coils are easy to get and plenty good-enough for the TB...

[spacecad3t]

Thanks Tom!

Look, here is the one long one compared to 3 same size bolts. These had yellow paint.

I ordered new hardware with the helicoils. I seems I may have used the long bolt on the outter two holes and wrecked their threads. The 2 holes closer to the intake runners seem to be intact.

[Tom]

Thanks Tom!

Look here is the one long one compared to 3 same size bolts. These had yellow paint.

All four should be 25mm long (~1 inch). Somebody used the wrong bolt in there, and it probably bottomed out and stripped the threads as you kept tightening. You can get M6x25 bolts at most hardware stores (along with an M6 heli-coil kit). You can use the standard shiny silver (zinc-plated) bolts from the hardware store, or shop around a little for the yellow versions to look more original. They are both electroplated in zinc (no paint); the yellow ones just get dipped in "yellow dichromate" after they are plated to give it that yellow look. You might also find them in other colors using a similar process. Just FYI so the Porsche gods look favorably on you and your car.

[spacecad3t]

I fixed the threads and have the throttle body installed with new hardware and new o-ring. I double checked the TPS with a multi-meter.

All four bolts are bolts are tight, I don't want to even try adding more torque to them. throttle stop is checked, in fact I have it loose right now. Throttle is also slacked alot.

Car started, but is idling at 1400... So I started spraying carb cleaner and using a rubber glove around the throttle body seam, and other parts, no change. Sprayed cleaner all over... no change.

Im scratching my head now and have made my situation worse and my idle bypass is basically closed... so where's this leak? Im going to smoke test it tomorrow.

Any other thoughts?

One tidbit, I added lock washers to the new bolts on the throttle body. I didnt think it would matter...

[Tom]

What happens if you disconnect the TPS?