thomasmryan

run a fresh wire from Pin 9 at KLR to Pin 21 at DME.

WPO

What is the function of this connection between DME & KLR? Can be done of course as long is I know what this does

Thanks for the suggestion!

thomasmryan

http://forums.pelicanparts.com/porsc...r-problem.html

WPO

Thanks.

However, we've tried to connect pins 9 & 16 to bypass KLR. If the car works otherwise and there's a jumper between 9&16 what is supposed to happen and how the car is supposed to run? That eliminates a KLR failure out of the question?

In our case the car ran the same with KLR in place and the pins jumpered.

Jfrahm

I'm circling back to a boost leak, I know the thread says it was pressure tested but maybe that was flawed somehow. I suggest a smoke test with the car under load. It's no big deal to use the brakes for some testing under load in the shop/driveway if the car is safely lifted, just only ride them for the length of a good hard stop and then let them cool off.

I could not really hear the strange sound on your video but that also might be more evident in the shop under load.

If you make a smoke rig to blow smoke in the intake yo might see a hose split open somewhere downstream. Doing this in the near-dark with a flashlight also helps the smoke be evident.

You can get smoke out of the Harbor Freight mini pump:
http://www.r3vlimited.com/board/showthread.php?t=253920

I use one of these to suck debris out of my hot tub and it'll draw without pumping if you get a venturi effect going. It might not make enough smoke for your purposes but you could scale up.

It's not boosting, and the cat could be heating due to the unburnt fuel from the metered air leak. Although I might have read that the exhaust manifold is also glowing red and that might not jibe.

Another thought: has the AFM been tested, retracked, replaced? Searching the thread for AFM I did not see that it had.

Perry 951

In my experience, a cranking compression test will be hard to detect a burned exhaust valve because most starters crank too fast. A cylinder with 40% leakage will build enough compression in about 3 strokes that you'd likely miss the slow buildup. A running compression test won't show much either other than balance between cylinders.

Burned valves usually cause a misfire at idle or very low engine speeds but clear up above 1500 RPM because of the amount of available time for compression. That is why a leakdown test is important.

That said, having all 4 exhaust valves burned to the point that we're dumping enough fuel/air charge into the exhaust to make headers glow at relatively low load would be extremely rare.. especially since this car seems to run well at idle.

I'd still like to see the fuel pressure and O2 readings.

Perry 951

I went back and listened to your video with headphones and the "wizzing" noise you are talking about sounds like a wastegate or possibly bypass (blowoff) valve opening to me.

Is the car equipped with the factory cycling valve? Have you perform any tests on it? Are there any broken nipples or cracks in the valve body? Have you pressure tested the bypass valve? Does it actuate with vacuum/pressure?

Speeddemon944

Check your ABS sensors and ABS computer - you said you tracked it then it started acting up. Did he run over the gators (the red/white bumpy things) a lot? If so, you can trip out the ABS and it does go into a 'limp mode' of sorts and will not boost over 0.2

Pull the ABS relay and then drive it.

WPO

This is easy enough to test so we'll do that. Does it lit the ABS warning light when such problem exists? Just asking as the car has no ABS warning light illuminated.

We've kept a small hiatus from this project as it really started to get under our skin - well perhaps this coming wkend we'll try to work on it a bit more.

Thanks for the tip, appreciate it!

Speeddemon944

Sometimes but not always. Also - pull the ABS sensors and visually inspect them. They can ohm out good but still be damaged that the computer won't get a good reading. The rears in particular are prone to getting the little tabs on the end of the sensor knocked off or ground down if you have a rear wheel bearing fail or begin to fail. The little tab should be between 1/4"-1/2" long. Here is a side by side comparison of a good, used one and a bad one.

Both sensors ohm'd out correctly according the manual - both at the sensor pigtail and at the DME harness.

WPO

Had a chat with my buddy today and there's no ABS in the car - so even that can't be the issue

Next gameplan is to take the car again to dyno / rolling road and check how much the advance changes when the car is under load. If this is found to be OK then the problem is evidently somewhere else. Oh the joy..

Perry 951

You didn't follow up about my suggestion to test the bypass valve, cycling valve, or wastegate. The sound to me is of air bypassing, not a boost leak. A bad bypass valve will cycle boost from the charge pipe back before the turbo. You said you blocked off the boost port in the wastegate too. What is the spring rated at? If no boost source is present and it has a weak spring, the gate will open.

Spending more time trying to see if timing is changing seems wasted to me. You're looking at a result, not a cause.

WPO

You are correct on the timing. The issues is not with the timing as this was checked and it appears that timing moves as it is supposed to. Glowing red header kind of threw us off the track as that indicated a timing problem + lack of power. Well at least we did get familiar with DME, KLR and sensor wiring

The O-ring in the throttle body was flat and quite hard so that was changed and the problem didn't go away.

The sound comes somewhere from around the TB though - or so it appears.

Wastegate is a new Tial unit and I don't remember which spring it was but I think it was the stiffer one. I need to check this from my buddy and I'll get back on this one.

Cycling valve has been tested so that it clicks when power is applied. The hose going to the turbo from the cycling valve has been blocked so the turbo should give full boost regardless so even if the cycling valve would be faulty it wouldn't cause a problem? Or can the valve leak from inside out?

Is there a correct procedure to check the bypass valve? Said valve has been tested by blowing / sucking air into the valve and at least the diaphgram is not broken is it doesn't let air through. Of course we may have tested this the wrong way?

Van

I bet you have the wastegate installed incorrectly and/or plumbed improperly so that as soon as there's intake manifold pressure, it's opening the wastegate. If I recall, the stock WG uses a pressure line to overcome stock spring pressure, but the Tial might use vacuum to stay closed.

Van

P.s. run the car a little bit and use an IR gun or thermal camera to see if the pipe from the wastegate is hot. If it is, then your wastegaste is letting exhaust gas past when it shouldn't be. Wastegate should only be opening at full boost at WOT.