77 transporter starts but won't run

[Sneeze festival]

Hello all and thank you, some basic pretext I suppose, I recently purchased a 1977 bay window. In the past I've had a 1957 Beetle 1974 Super, 1973 Super, and a 1971 bay, so this would be my first type for motor, it hasn't run in quite some time I flushed out the fuel tank replace the fuel lines and change the fuel pump, and now it starts but will go for about 30 seconds and then stops. What would be the next thing to check?

[airschooled]

Hi there, and welcome. I'll get to your question in a second, but I want to make sure you have the Air Flow Control (L-Jet) fuel injection training and troubleshooting manual, available from the "Technical" tab on here.

https://www.thesamba.com/vw/archives/manuals/afc_fi_training_troubleshooting_manual.php

You do have the original fuel injection, correct? If not, let us know if you have single or dual carbs. Our answers will depend on it.

If you have fuel injection, please know the system is EXTREMELY sensitive to leaks (air flow control!) A ripped or unplugged hose can wreak all kinds of havoc on the system. Luckily most of the essential hoses don't share sizes so it's very rare that swapped hoses could cause a non-runner. (Disconnected hoses ABSOLUTELY can though.)

The FI system also has a warm-up enrichment, provided by the Cylinder Head Temperature Sensor (Temp Sensor 2/TS2.) My guess is that you have an air leak, and the TS2 is helping keep your system rich enough to start up for a bit, but the eventual lean-out from the sensor telling the ECU the engine is warming up is casing a stall.

Another excellent read :
https://www.thesamba.com/vw/forum/viewtopic.php?t=513607

Good luck, and have fun reading about the system. It's reliable if you pay attention to detail and pay for correct quality parts.

Robbie
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