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  View original topic: 1984 Westfalia Cranks But Not Starting..
WillRB Fri Oct 23, 2020 3:52 am

Have a 1984 Westfalia with stock 1.9 motor. Trying to get it to start. When van was purchased I got the motor started by spraying gas directly into throttle body. Van cranks but does not start. Here is the background information so far:

- Fuel Pump works with good pressure but I have to jump relay to get it to run. Relay works fine but do not appear to be getting proper ground to energize relay. If I tie to a ground relay functions.
- Injectors are not spraying, I was able to get good spray from one by applying 12 V through ecu harness connector
- I have Battery voltage at coil up to ignition module plug (connector #4?), but notice a slight voltage drop from module to ecu (connector #7). I went ahead and replaced the module since it was relatively cheap and did improve my drop but it is still there (~11V).

I have been through manual troubleshooting and feel as though it is fairly obvious from my symptoms that my ecu isnít functioning correctly. What I donít know is whether or not the drop on the voltage to the ecu is causing it to not function correctly or if I simply have a bad ecu. Hoping to figure this out before shelling out the money for a working ecu. I will admit that I have read about the ground issues on these vanagons but havenít gotten to a full on inspection cleaning of every single one. The grounds that are easily accessible have seemed to check out (block, #7 ecu chasis ground) so far.

Any help or insight into my potential issue or where I should go next would be greatly appreciated. If additional information from me is needed please let me know.

-Will

mikemtnbike Fri Oct 23, 2020 9:57 am

Have you tried a fresh ignition switch?

WillRB Fri Oct 23, 2020 10:52 am

I have not tried replacement of the ignition switch yet. I have a new one on hand though. I will swap it out and see what happens.

Thanks.

Wildthings Fri Oct 23, 2020 11:01 am

The fuel pump relay is grounded through the ECU which take power to operate, the ECU gets its power from the fuel pump relay, which requires both power and a signal from the ignition switch to operate.

RawUmber Fri Oct 23, 2020 11:12 am

If ECU is alive and able, it will prime the fuel pump for ~1s right after key on.

If the ECU has a bad fuel pump circuit but is otherwise good, and you have jumped the fuel pump relay to get the pump going, the ECU should work and pulse the fuel injectors normally so long as it's getting a proper hall pulse on its pin1.

If the lowest your ECU's battery+ goes to is 11V, that's no problem (when cranking it's often lower than that). You might make sure your ECU's pin 25 (ground) pin is ~same as vehicle frame (low ohm difference).

The ECU provides a ground pulse to the Fuel Injectors to cause them to spray. Not quite sure how your 12V caused them to spray, but maybe irrelevant.

Given the above stuff checks out, it does sound like a bad ECU.

camperseth Fri Oct 23, 2020 2:37 pm

I just went through this myself. Save yourself the torment and find a good 1.9 ecu and try that FIRST!!!
Definitely go ahead and clean all the grounds.

WillRB Fri Oct 23, 2020 3:54 pm

Replaced the ignition switch. Still no fuel pump prime or squirt from injectors on crank. Think i may have found an ecu to borrow. Thanks for the help so far anything else I should be checking? I have done searches prior and didnít really find anything on a more definitive way to check ecu status? Did check the ecu connector grounds to engine case ground, ohms very low 0.5.

WillRB Mon Oct 26, 2020 3:31 pm

Follow up for those who find this thread down the road. It was the ECU fired right up with borrowed unit.

-Will

bobhill8 Mon Oct 26, 2020 5:10 pm

Sweet - thanks for letting us know and closing the loop.



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