geefunck88

my 89 200 tq cuts out like it gets no gas when starting cold. if i shut the car off and restart while the engine is still warm it runs just fine. if the engine cools down for a while it will act like its getting no fuel. is this the cold start valve??

audiqv8

"if the engine cools down for a while it will act like its getting no fuel. is this the cold start valve??"

Most likely not. The CSV is for a cold engine not a cool or warm engine. The CSV acts like a choke on cars with carbureator, it help to enrich the air/fuel mixture with gas on a cold engine.

Most likely your problem is residual fuel pressure, which could be caused by the fuel pump check valve. Or you are getting vapor lock after the car has been sitting for awhile.

Check for spark when the car doesn't start. It could be a sensor that has become "heat soaked".

Crank the starter and see if the tach bounce, if it bounce then the rpm sensor is OK one down and two to go. The other two sensors Hall (aka cam sensor) is located inside the distributor. This could cause a no start condition. The third sensor is the CKP (crank position sensor). Both crank and cam must be in sync before the ECU will send a trigger signal to the coil.

So next time the engine doesn't start check for spark and learn how to pull DTC (diagnostic trouble codes).

geefunck88

the car starts everytime its just when you go to hit the gas it sputters. after a few seconds of this it just decides to go and then runs fine. if i stop at a store quick and restart it it wont do the same thing it just goes normal. only after long cool down it will sputter a little again. i also noticed there seems to be more pressure when i take off the gas cap than normal. is that part of the residual fuel pressure your talkin about? and the tach does bounce when i start it.

Audi Junkie

Note on Hall Sender check. A bad one will send a single spark after cranking.

Kneale Brownson

The fuel system is supposed to maintain pressure enough to supply fuel instantly when you try to start the car. Your symptoms sound like maybe there's a bit of fuel available for the car to start after sitting overnight, but not full pressure so the engine runs out of fuel momentarily until the pump rebuilds pressure. The valve that's supposed to control this should be on the top of the pump, which, of course, is in the bottom of your fuel tank. That valve is called a pressure regulator and it's number 34 in the pix.

<img src="http://www.vagcat.com/p/B088/024100.png">

serf2k

I thought that #34 is the noise supressor. The check valve that allows fuel pressure to leak down overnight is #30
Every troubleshooting adventure should start with checking the codes......what do they say?
Cheers!

Kneale Brownson

I guess I got mixed up because my cars have the liddle pumps with the internal check valve and no external damper. The #34 screws onto the top of #30. ETKA calls 34 a "pressure damper" and 30 the nonreturn valve.

geefunck88

are all of the parts on that picture in the fuel tank??

Kneale Brownson

All the ones associated with the pix of the fuel pump itself are in the tank. You follow the lines to the opening in the tank. There's a hose (9) and some wiring from the pump that connect to the bottom side of the fixture that caps the tank opening. Rest of the stuff in the pix is outside the tank.

serf2k

Make sure that you observe the orientation of the float arm and the hose to the pump inside the tank - if you get it wrong your fuel gauge will not work properly.
Open the tank locking ring with a non-sparking (brass) drift and be careful in there - make sure most of the gas is out of the tank and you work in a well ventilated area.
Cheers!