Wet Electrics Troubles!!!

Grant Garrison · #1 (**permalink**) 09-21-2001, 01:51 PM

Sad, sad day for my new Superformance Cobra. I've had it for about a month, and have already put 800 miles on it (can't keep my hands off of it!). Little adjustments here and there (rear sidepipe brackets broke, went back to a regular alternator pulley to cope with the fuel injection's electrical demands).

Then I got stuck in a BIG rainstorm about 2 weeks ago. Rather than sit under an awning and wait for it to pass like an intelligent person, I decide I had to get it to my garage NOW.... the net result being that I went thru some flooded-out roads, getting splashed by big SUV's and barely made it home on 4 cylinders. Top was up, for what that was worth. The car (and I) were soaked.

When I got it home, the headlights went on all by themselves, and would not go out, so I hit the kill switch. I cleaned it, let it dry out, and it still was barely able to run. So off to the engine builder's. He discovers that the Accel brain box had gotten wet, resulting in severe corrosion of all the pin connectors on the box. The box itself got a little wet, primarily from water dribbing down the A-pillar holes (time for some silicone sealant). He swapped-out all the EFI sensors, and spark plugs. The MSD box appears OK.

Now here's the weird part:

I picked it up last night, and it was running great. Full power, not a hiccup in sight. Then a slight hesitation was felt up near 6000 rpm. Then it started doing it at any speed, and I barely managed to cough my way back to his shop. It's now running just like it did when it was wet.

20 minutes of running perfectly, then within 2 miles it gradually went to hell. The only clues I can offer are the ammeter reading a constant charge of 25 amps, then the needle started vibrating like crazy (from about +10 to +30 amps). Also my Valentine radar detector now goes off whenever I accelerate hard. It NEVER did this before the rainstorm, and the detector does not act up in my other car.

Sorry to ramble on forever, but engine builder wants to send the Accel brain back, which will cost me big and may take 6 weeks!!!! Neeedless to say, I'm bummin'. Any thoughts?

Thanks!

Mike Braddock · #2 (**permalink**) 09-21-2001, 05:27 PM

Grant,

First thing that concerns me is that you say your mechanic swapped out all the EFI sensors and plugs. Do you mean he actually replaced all of them, or he pulled the connectors, cleaned and reconnected them? If he replaced all of the sensors I would suggest finding another mechanic, as that would indicate he does not know how to troubleshoot a FI system.

Sounds like you have some ground issues. I doubt there is anything wrong with your Accel ECU and a little water won't harm the MSD either. It sounds like your mechanic stumbled across the ground problem when cleaning and/or replacing the EFI sensors and that was enough for the ground to temporarily work well enough for the engine to run again.

Finally, I would have an alternator shop check the output of your new alternator, as it sounds like that could have a problem with the internal regulator. You should be able to take the car to a decent auto parts store and they have a diagnostic scope they can check the output with without you having to remove the alternator.

Mike

Grant Garrison · #3 (**permalink**) 09-22-2001, 07:46 PM

Mike-- Thanks for your excellent suggestions, I will follow up on them. As a little defense for Mr. Engine Builder, He had lots of identical sensors sitting on the shelf; it was easier to swap-out as a first check (and no charge!). I agree about both the ground fault and alt. check.

As an update, today engine builder and I put new (hotter) plugs in. The old (racing) plugs got all trashed when the car was running bad. I also charged-up the battery, in the event a low batt. was causing any computer malfunctions.

Surprise, sur-prise! It ran great ALL day. Beat the hell out of it, put about 80 miles on it, and not a trace of problems. We're completely mystified.... just waiting for the computer to dump. But it didn't.

There's got to be SOMETHING else wrong under there. It just hasn't decided to show itself today. Fine by me! At least I got my Cobra fix in.

Bill Wells · #4 (**permalink**) 09-25-2001, 04:23 AM

Grant....any 'fixes' found yet to your described electrical woes ? Interesting engine, I have not seen a 427 EFI engine yet in one of these and being also in the Detroit area as a fellow SPF owner hope to see your car locally at some event. Good luck with your search and rescue mission. Bill (ps..I would 'guess' you are with FoMoCo, from which I retired in 98 after 30 yrs) also, offline sometime I would be curious as to which local shop did your engine work as one of these days I am going to 're-power' mine to a BB combo of some kind.

Grant Garrison · #5 (**permalink**) 09-26-2001, 08:18 AM

Bill--

No news yet, given it's been raining virtually non-stop since the weekend. All I can really do now is drive it until it goes bad again. Have no idea if the problem is in the Accel computer or not.....
It sure ran great Sat. however. Came up on a couple of superbikes, and totally trounced them!!

Yes, I'm employed at FoMoCo, in Corporate Design. Perhaps I should clarify about my engine: It's a Windsor small block, but I went with the SVO "W" siamesed-bore racing block. This has 4.125" bores, and with a 4" stroker kit, you can get a 427 cu in SMALL block.

It was built by Brian Thomson of Thomson Automotive in Redford, whom I can highly recommend (I can't blame him for my ECU getting soaked!).