2003 zts intermittent start problems

"billsguy" wrote

See if you can borrow another battery (known to be good) and try that out for a while. Sometimes batteries have loose plates or dirt which can cause intermittent random internal shorts and therefore low voltage.

battery wouldn't be it. sounds like it's the typical focus fuel pump problem. it was a problem on the 00's and 01's but more 02's + are seeing this too.

Can't be the fuel pump. The original poster said

Bit of a stretch here, but you have something like a Mobil Speed Pass on your keys? They may interfere with reading the chip in your ignition key.

Once in a great while, my 2001 won't start. Turn the key and absolutely nothing. I don't recall any whirrrr. I take the key out, hold the key ring by the ignition key so everything (including the Speed Pass) hangs down, try again, and it works.

Ah, good call.. Thanks for clearing that up. :)

"Tony Wesley" wrote

Yes, for me the whirrr is the key piece of data. Chances are it's the fuel pump. There's enough voltage to power it up, but not activate the starter.

Try taking the speed pass off the key ring. The speed pass could be screwing up the Passive Anti Theft System causing the starter to be intermittently "locked out". The speed pass could be blocking the signal from the key chip. When you have this problem does the red light on the dash flash or flash rapidly? If it does, the chip in the key is not communicating with the transceiver around the lock cylinder.

You should also rotate the use of the second key and remote control about every 3 months.

"Tony Wesley" wrote

Yes, for me the whirrr is the key piece of data. Chances are it's the fuel pump. There's enough voltage to power it up, but not activate the starter.

That is, it's the fuel pump that's whirring? You might be right.

I think your suggesting is better than mine.