superloaf

My 951 won't start after being left in storage for a year and a few months. Car cranks but will not start. I've found that there is no spark and I've jumped the DME relay so it's not that. Also checked the distributor and rotor which are good along with timing belt. Oh, my tach does not bounce when trying to start. Now I'm in the process of checking the coil, crank sensors and DME. I replaced the ignition switch about five years ago so it shouldn't be that but I'll check that also at some point. The car leaks and was left outside so it did get wet inside and now I've found the passenger floorboard to be wet. Hopefully it didn't get into the DME/KLR but I'll know soon. I just wanted to get some questions answered and see if there's anything else I should check. The main question I have right now is about the crank position and reference senders. How many are there? I've seen some info that says there are 2 crank and 1 reference sender but I always thought there was just 1 of each. And if there are 3 total, where is the third? I see the 2 connectors that are in the metal bracket between the intake manifold and the firewall but I don't see a third connector or cable. Also, my 2 connectors that I see are broken and have been that way for around 10 years but I secured them and haven't had any trouble from them in the past. My problem is that the broken part is on the wiring harness and can't be replaced by simply replacing the sensors; it needs a new harness to fix it. I remember someone had a fix for the harness a few years ago but I can't remember who it was. I think it was around $200. Does anyone know who sells a replacement?

Anyway, thanks in advance for any help and hopefully I can have this car back up and running without a new DME....

kev951

did you recharge the 12v battery after storage and trying to start the car? there are 2 crank sensors, one is speed , the other is reference. the broken harness is not helping you here. Try having someone crank the car while you gently wiggle the broken part of the harness to attempt to make a stronger connection and see if you have spark and or the car starts etc. If the car got wet during storage, check you battery grounds to the body and to the cylinder head.

superloaf

Used jumper cables from an Audi A8 with a 200 amp alternator and it was getting full cranking power. But I've found the problem: the car developed a new leak up front and water made its way into the DME and KLR. The connection harness was very wet and there is also water inside the box, mostly dampness but still a fair amount of moisture. KLR is slightly better. I have the covers off and will attempt to dry them out. Has anyone had any luck with them surviving water intrusion? Doesn't look promising....

I'm aware of ecu doctors and Focus 9 but does anyone have any other recommendations or cheaper options? I know it's money well spent but rebuilding both is a lot of money. Of course, could be worse; could be a Boxster!

kev951

get some DEOXIT spray and cleaner and let it dry out, take the ecus out of thier cases and liberally spray spray spray and let it dry in the air. the water ingress is likely due to clogged drains in the battery tray area

superloaf

My water ingress was kind of a fluke. The car was parked on a slight angle where the right front is slightly lower and when the water from the sunroof drains into the battery housing, the water flows along the little shelf where it found 3 holes that are in that area from birth. For some reason Porsche has bred drilled holes in this area that they leave open and only covered by a strange undercoating material that over time falls off. I patched one years ago withe the red silicone but the others were covered by the undercoating material so they never caused problems. But that ship has sailed and now they are open holes siphoning the water directly over the DME and KLR. So I've covered the other holes with silicone and hopefully that will end the water leakage into the electronics. Just hope the damage isn't terminal for the ECU's.






Don't mind the sloppy application but I could only find one slightly dried out tube of PVC and it was tough to get it in place in its dried out sticky state.

Anyway, check your battery area for the exposure of these holes as you don't want to risk killing your DME for such a stupid reason!

kev951

if you remove the battery itself, there are drain openings there that get clogged with debris. remove the battery , pour a cup of water and if they are clear you will see the water draining out of the lower fenderwell near the end of the door sill

superloaf

Good call and thanks for the reminder as this story is more complicated because a few years ago I noticed some corrosion damage to the body under the battery so I fashioned a less than perfect patch using a bit of stainless steel sheet metal and body filler. Well, rust may never sleep but rust from battery acid is much worse! So after Kev's post above I thought I had better check out this patch and so glad I did! At first all that could be seen was a crack in the body filler above the metal but after removing some of the filler and body coating, the metal below was all rust. I removed the rust and questionable metal along with the filler. I have some POR-15 that I thought I'd try first but after reading the instructions, it says the first step of cleaning solution must be washed away and I'm not sure how I can do this with the giant hole directly into the passenger floorboard. I'm not sure the best way to go from here. Obviously a trip to a body shop is the best way but even just getting an estimate is a pain since the battery will need to be removed and all that. Not a huge deal but it does complicate a quick estimate....

But anyone have any helpful ideas for a DIY fix? Obviously, there is no worry for finish and paint perfection as this area is almost entirely unseen so my only concern is durability and future rust prevention. I know that's impossible for me and near impossible for a professional body shop but what do you guys think I should do?

Some pics for the damage:



-The first look doesn't seem so bad until you spot the crack.






-Close up of the crack and small metal perforation.






-After removing the damaged metal.





-And how it sits now with the giant hole into the passenger dash/footwell and also damage into the engine area.

whalenlg

I faced a similar situation - but concluded that the only long term fix was to have a guy from a body shop cut it out and weld in an undamaged one I found on eBay. I was happy with the results.

superloaf

How much did that cost? Just curious what a professional method would cost. And I didn't think of obtaining a cut out body section; great idea! Thanks.

whalenlg

I believe the used part was about $300 governor take and the labor to remove, weld and paint with sealant was about $500. Not cheap by any means but I didn’t have a choice as I could see the floor mats from the engine bay.

whalenlg

“Give or take”

superloaf

Thanks for the details. Yeah, gotta fix this as I’m not in Los Angeles anymore otherwise i could wait nine months….

i saw some articles on UV epoxy that might work or some of the modern water sealing products but not sure if this will work as claimed or if it’s all a lot of hype.

Also, does anyone have experience with POR-15? Would that stop the rust here or is the battery corrosion too much to deal with without completely cutting it out? I haven’t had much luck with rust converters but I’ve only used other brands and each brand seems to be different. POR requires complete washing of the first two solutions but I’ll just have to hose it down and clean up the water that gets into the car later. The complete ECU is not in the car now so no worries about that getting wet again.

Thanks again.

Dan Martinic

POR-15 will not fix your issue, sorry. Only new metal can do that here

Gage

The visible corrosion is also not the extent of the damage. The floor component of the battery tray extends outward to the inner fender wall, beyond what is visible, below the box section extending rearward from the strut tower. You can inspect the box interior through the three plastic plugs in the vertical wall. An access hole can also be cut in the inner fender wall (fender removed) to help with the repair. Good luck, this is an essential but certainly not an easy repair.

superloaf

Ended up using stainless steel cut to fit, lots of sanding and grinding and a bunch of POR 15, both the normal and the patch putty, to fill up the missing sheet metal and treat the rusty bits. It turned out better than I thought it would and is holding water out of the passenger compartment, at least for now. I know it's tough to kill rust but I did remove and grind the bad parts and then did a double layer of new metal both to seal the hole under the battery and then a top layer to seal out the water from the top and all covered with more POR 15. POR 15 is pretty interesting in that it dries to become an insanely hard coating but also remains slightly flexible so it should flex with the metal for vibration, flex, or temperature change. If it works as they say it does, it should keep the water out permanently and if it doesn't, then it should still keep the water out for a few years and by that time I'll have a welder to fix it properly. I guess we'll see but the real problem here is the corrosion/rust from the battery acid and if the POR 15 can stop it. I did do the full three steps with POR 15's cleaner/degreaser and metal etch before applying the coating and putty.

Final result is decent enough for a space that is never really seen. And the water egress into the ECU doesn't seem to be causing any longterm problems, (knock on wood) but in case you're thinking I'm awfully lucky and carefree about all of this, it's probably because I also have a 986S that I'm trying to get running again and if you've ever seen how things can go horribly and expensively things can go with the M96 engine/transmission, then you will understand that all 944/951 problems are super easy and carefree, and cheap in comparison!



POR 15 with primer...

...and then a bit of black to keep out the UV rays.