TheSamba.com :: View topic

Wed Jul 23, 2003 9:40 am

Hi all,

If my 77 Westy sits for more than an hour, when I start it it runs rough, like it's not getting enough gas. I drive down the block and it's fine from then on. Any idea where to start to look?

-=Rob
'77 Westy
http://www.mrbreeze.com/vw1

Wed Jul 23, 2003 10:48 am

Carb(s) or FI?

Wed Jul 23, 2003 10:51 am

Sorry, Stock FI

-=Rob

Wed Jul 23, 2003 2:57 pm

I'd think start with a basic tune-up. Jeremy

Wed Jul 23, 2003 3:06 pm

Yeah, I was thinking that might be a good idea. Maybe change to electronic ignition while I'm at it

Wed Jul 23, 2003 5:26 pm

Check the head temp sensor II next to the #3 cylinder. At 68 degreesF you should have a resistance of 2500ohms. This sensor comunicates with the ECU telling it if the engine is warm or cold and adjusts the mixture accordingly. It is probably running to lean at cold start up if the sensor is bad.

Jasan C.

Wed Jul 23, 2003 8:21 pm

The cold start valve is a possible problem and easy to check. Just take it out of the center air distributor, but leave it attached to the fuel rail. See if it sprays a nice fine pattern while cranking the bus with the engine cold. The cold start valve can also get clogged from time to time and spit droplets of fuel rather than a nice cone shaped pattern. If it does you can remove it and soak it in a good carb cleaner then use a fine wire brush on the tip of it. Sometimes they leak and spit droplets also. If it's leaking you may as well toss it and get a new one. Lastly, if it is not spraying anything while cranking a cold engine then the thermo time sensor may be bad. If so then check the Bentley manual for the complete test procedure or get back to us here in the forum. Good luck.

Wed Jul 23, 2003 8:39 pm

I have a similar problem on/off that I will get to when I get my bus back from the painter. I've ruled out many of those issues and I think it's a sealing problem: vacuum leak when cold that seals up when hot.