logray

On the roof of the transmission well around the transmission bell housing there is a small black box that is a junction point for the positive lead going to the main fuse terminal behind the battery. The cable coming from the positive jump lead on the engine connects to this junction point. There is also a positive lead that forks off to the DME and relays/fuses behind the rear seats. I've read a few posts where this positive terminal can get filled with junk and corrode the cables or connection point.

Also how do you know that the main battery cable on top of the engine isn't corroded? Just for fun, have you replaced it? It is not an expensive part.

What is the condition of the main battery positive cable coming from the main fuse box (you have to remove the battery tray IIRC) to the battery. If your drains are clogged up in the front this area can see/fill with more water.

Have you cleaned the terminals or replaced the ground straps (one from engine to body and another from battery to body).

Any other excessive draw on the system during start? I.e. stereo, amps, speakers, lights, etc.

logray

If you've eliminated the wiring (and your replacement cables are as good as or better than OEM including the crimp/soldering/gauge) then I would agree and guess your starter is getting tired even if it passes bench... just live with it until it dies? And then just for kicks whack it with a hammer a few last times before it gives up the ghost... then just bump start it until...

Kazual99

"Also how do you know that the main battery cable on top of the engine isn't corroded? Just for fun, have you replaced it? It is not an expensive part."

I replaced this cable with Monster cable and connections as well as the cable and terminals at the battery.

"What is the condition of the main battery positive cable coming from the main fuse box (you have to remove the battery tray IIRC) to the battery. If your drains are clogged up in the front this area can see/fill with more water."
Drains are clear and sliced into the cable to inspect then re sealed with heat shrink.

”Have you cleaned the terminals or replaced the ground straps (one from engine to body and another from battery to body).” Replaced these at the same time in preparation for amplifier/stereo upgrade. Connections: Heated wire with mini touch to imbed solder them mated it to the connection terminal via crimp. 4AWG

"Any other excessive draw on the system during start? I.e. stereo, amps, speakers, lights, etc." Nothing extra during start, but when cold the car fires right up...no issues at all.

've read your post over on Renntech and your findings lead me down the paths above. Good posts you have with alot of explanation. Thanks for taking the time to respond.

Kazual99

I gree

The one part I didnt look at was the connections on top of the transmission well. I will replace it as well. I have plenty of 4AWG at the house...

logray

IIRC the OE cable gauge is 2AWG or 3AWG. Pretty quality solid core low strand cable.

Also, since you made your own it's important that the crimps are done properly, otherwise the strands can break down the road due to vibrations. The crimpers that just clamp down on two sides are inferior to the ones that do it from all sides.

logray

Well if it looks OK, I wouldn't touch it... unless you want to replace with OE part... since it is fairly well protected from the elements...

Kazual99

Update:
After having the starter tested and many, many threads later I decided to replace the starter. During the R&R the oil filler tube broke, the alternator removal was a pain again (3rd time R&R), several broken hoses for the SAI. All and all it was a good project, replaced the starter and all is good and the car drove fine for three days and then... CEL. Now I have a SAI CEL.

I did notice right before the CEL popped on I had just completed a 45min drive to cars and coffee and the engive was at proper operating temp. The SAI pump turned on then off and the light popped on.

I thought the SAI pump only ran during initial startup when the engine was cold. Could this be an indication that the sensor which tells the SAI system to function is going bad or giving false information?

Thoughts?

Side question: Is there a process that we can use to "program" out this system?

logray

Good choice, glad to hear that solved the problem.

It's perfectly normal for the SAI pump to run at other times too, not just cold startup.

What is the CEL code? Guessing a gummed up check valve or a misplaced vacuum tube.

You can re-flash your DME with a RoW program and it will ignore the SAI system (and several O2 sensors and perhaps bank 2 CPS), but it won't pass emissions if your state requires a smog test.

Kazual99

I'm more inclined to think it's a misplaced hose or one that has become loose. The CEL was off prior to the starter R&R and I did knock a few hoses off and found one baldly cracked. Anyway, I'll dig into it later in the week.

logray

You can buy that plastic tubing by the foot, it's really cheap. And the little rubber connectors are cheap too. Don't ask me for part numbers though. That whole thing is a big headache. I replaced all of mine along with the check valve and a good cleaning. Should be trouble free for another 100k..

Kazual99

I'm going to replace the 2 check valves, the front change over valve, and the shut off valve.There is one hose from the change over valve mounted above the alternator that dissapears into the rear of the engine by the rear intake righthand side. Any idea where that hose connects?

logray

Into a tube into the resonance flap located in the rear intake plenum cross over.

The hoses are 19-21 in this diagram going into the flap:

http://www.autoatlanta.com/porsche-p...-05/107-10.php

Kazual99

Life is good. CEL is gone, slow starting....gone. Car is solid and I'm driving the dream.

Thanks Logray for all the help.

dsowen

I doesn't sound like you replaced the transmission to starter ground strap as suggested by Joel. I would do this even if it tests good and is not corroded--electrical gremlins are transitory and difficult to pin down.

chsu74

Here is a good thread on it from the 997 forum.

https://rennlist.com/forums/997-foru...w-voltage.html