couchaudi

2001 A4 1.8TQM

My a4 refuses to start if it's cold. It's 30 degrees here in Stevens Point and apparently that's cold enough.

I have replaced:

-All coil packs (Dealer replaced under recall last week)
-Vac line from EGR
-Coolant temp sensor
-Plugs

Fuel pump works and I can smell some gas after cranking for a while. The only code it throws is Catalyst Efficiency below threshold; otherwise the car runs great.

Any ideas?

audiTLC

ingition module? check valves?

couchaudi

Is there a particular check valve that I should....check? haha
And how should I check them? Just blow through them and make sure they're only one-way?

turbo510

Check for spark. Take a coil pack off, ground it securely, reconnect to the ignition harness, then put a spare spark plug in. You might have to tie the plug up towards the coil pack so it makes good contact with the spring. With the plug touching the valve cover, have someone crank while you watch the plug.

couchaudi

Did it; spark is good on all four. Spark, fuel, and compression are all present and accounted for. Thanks though.

turbo510

Boy, it should run. If you pull the throttle-body hose back and spray a shot of starting fluid past the plate, what happens then? Could you have disconnected an intake hose somewhere, around the turbo, etc?

couchaudi

I haven't tried to use starting fluid yet. Like I said before, it only happens when it's cold, and I try to shy away from starting fluid till the bitter end. What really perplexes me is that it'll start up just fine when it's warm. It'll hold 16lbs. of boost all day long, so that leads me to believe the intake hoses are OK.

Usually after cranking it on and off for a good 15 minutes, it'll slowly sputter more and more till it starts. Once it starts, it sounds a little unhealthy/low idle for ~30 sec, then, after that, it runs great.

Any other ideas?

turbo510

I have found WD-40 volatile enough the light off an engine, so if you spray some fuel in and it fires right away, then the problem is not enough gas. You said that the coolant sensor was changed; see whether the computer reports a reasonably accurate temperature. Another possibility might be the fuel pressure regulator or fuel pump. I know you said the pump runs, but I just changed mine (though it failed totally, not low pressure).

audiTLC

check my sig line they might help

couchaudi

Will do. Thanks.