fast ignition starting problem...weird..

[AmirTech]

Car? 97 Talon TSI AWD AT - 91K miles.

I have this starting problem that only manifests itself if I turn the ignition quickly from: off -> on -> crank.

If I do: off -> on -> wait 5 seconds -> start, then it's fine.

What happens during the problem is that it cranks forever without starting. It feels like a fuel issue IMO but I have no clue what it could be.

I guess I have a workaround cuz I know how to avoid it, but it would be nice to fix it . I haven't checked plugs/wires/etc cuz it doesn't feel like that. I bought a fuel pressure guage but haven't had the chance to install it yet.

Any ideas?

thanks,
Amir

 

[luv2rallye]

Sounds like fuel pressure isn't being maintained (in the fuel rail) as long as it should after engine is turned off. Check if fuel pressure regulator (on end of fuel rail) is bad.

 

[blue92laser]

As you are starting it, does the stock boost guage zero out or does it just sit there at the bottom of the vacuum spot?

Reason for asking...

I had an ECU problem where it wasnt turning on right away, i would have to wait a few seconds in between off-on-start.

If the boost guage doesnt zero out when u put it to the on position, check out the caps on the ECU. Remember our stock boost guage is electrical signals from the ECU measuring a rough electronic signal of boost. Not accurate, but can help figure out problems still.

Let me know how it goes.


Also, when ur engine like was thrown did u here a click or a popping sound coming from behind the dash where the computer is?

 

[AmirTech]

luv2rallye: Is there any way to test the FPR?

blue92laser: I didn't stare at the boost gauge..will do so next time. I thought ECU as well at one point, but have any 97s shown leaking caps yet?

thanks,
Amir

 

[AmirTech]

The FAQ says if you figure out a problem, you should post up the solution....well here goes....

I first thought it was my fuel pressure solenoid, so I tried bypassing it. It seemed to help a little but didn't fix it.

My problem was my temperature sensor. This is located right around the radiator cap. It's the one with the two prong connector on it with the 19mm (3/4") nut.

It went bad, but not bad enough such that it would throw an ECU code. I had no ECU codes. The way I figured out the temperature sensor was bad was I was sitting in a parking lot started and the car started nearly overheating. When I started driving around (to get to a gas station) it went back to normal. I tested if the fans/relays/etc were working by testing with the AC. With the AC on, both fans would turn on. This all pointed to the temperature sensor.

Well...

After some reading I found out that the car is pretty dependent on this sensor for other things as well. Based on the temperature sensor, the car decided how much fuel to dump in the cylinders upon starting. It seems the car was (a) either starving it or (b) was dumping too much fuel. I'm not sure which.

So I changed the temperature sensor ($30 part) and off I went .

I hope this helps someone out .

thanks,
Amir