Log in

View Full Version : Bad Motor Behaviour Mystery to Solve



CliffH
08-12-2011, 11:00 AM
Ok, motor experts; try to solve this one:

My car, FF#1817, has a mild 5.0 engine (Ecam, headers, Cobra intake). It's been running flawlessly, except recently. I normally keep it in the garage and it is a little cold-blooded (idle needs a little help on startup, but once it's running it's great). So recently we had some rain (3 days or so) and I had to keep it outside, needing the garage for some home projects. It was all covered up (cockpit only). When the rain stopped it wouldn't start, only kicked over, gave a burst of ignition, then shut down. I tried giving it some help with the accelerater pedal but no deal. I could smell gas so that was ok but it was in complete no-deal. So I thought "Igintion" and replaced the cap and rotor, which looked a bit carboned-up. Still no deal. So it sat over the past few days while the atmospher provided us with lovely dry weather. This morning, baddabing/baddaboom, started up like always. So it's moisture, right? But where? It's still running rough when releasing the hounds. The fancy-schmancy red Saleen ignition wires have been in the car at least since I bought the wreck (1999).

So, does this sound like (1) computer (2) wires or (3) plugs? The computer is pretty well protected in the passenger footwell and I'm guessing moisture does not affect plugs. So, does this sound like bad wires, especially given they are probably 12 years old? Do wires (even fancy ones) get bad and break down?

Jeff Kleiner
08-12-2011, 02:14 PM
So, does this sound like bad wires, especially given they are probably 12 years old? Do wires (even fancy ones) get bad and break down?

Yes and yes.

Jeff

seagull81
08-12-2011, 10:04 PM
Also pull the distributor cap and look for tracking or arcing. Moisture can get in there and do funny things.

Bob Cowan
08-12-2011, 11:45 PM
Look at your connections, especially the computer plug and TFI plug. I'd almost bet that's where you get the moisture build up. Even though the computer is in the passenger compartment, sometimes water will track down the wires or there's a small foot box leak. Depending on where you live, humidity could even cause water to collect in tight spots like that.

Pull the plugs apart, put some silicone ignition grease in there, and plug them back in.

Ignition cables do go bad over time and use. If yours are from '99, I'd replace them. I wouldn't trust 12 year old cables.

CliffH
08-14-2011, 07:01 PM
Hey guys

Thanks for taking the time to help me. On your advice, I'll change the plug wires, check the EFI connector, report back. I did replace the distributor cap and rotor so it's brand-new. Don't touch that dial.

CliffH
08-16-2011, 02:36 PM
Up-to-the-minute news: New Autolite bog-standard "25" plugs gapped to 0.054" and Ford Racing 9mm wires = All better now, run like wind. Thanks again for the help, felliz.

riptide motorsport
08-16-2011, 09:26 PM
I just love a happy ending!!!