QuestionQUESTION: So heres the deal i have recently purchased this bus and it will not start. When i checked the wires for the fuel injection they were both hot. In the book it says you can check with an electrical tester so i am assuming one should be a ground. I can make the injectors fire with a jumper wire. If you could help i would appreciate it thanks.
ANSWER: Jerid,
I'm not sure if you are saying the fuel pump is working or not. Regardless, check out this previous post on a similar starting problems:
http://en.allexperts.com/q/Volkswagen-801/2008/11/1978-VW-Westfalia-tarting.htm
Also, here is an excellent resource of FI info:
http://www.vw-resource.com/fuel_injection.html
If you get stumped after reviewing these, let me know and I can give you more specific help.
Rick
---------- FOLLOW-UP ----------
QUESTION: Yes rick the fuel pump is working but the injectors are not.
If i put a jumper wire to the injector and ground the other side they squirt fuel but they wont by them self
Answer
Bus_Dbl_relay
*** Correction ***
Jerid,
Keep in mind the injectors will only squirt while cranking the engine. You probably already know this, but you can test this yourself by taking an injector out, leaving the electrical and fuel lines attached, then pointing the injector into a rag while someone cranks the engine.
If you cannot get fuel to squirt this way, I believe the double relay may be bad. Here is how to test:
(NOTE: This procedure assumes original wiring configuration.)
- Pull the coil high tension wire (to insure the engine doesn't start.)
- Turn the ignition ON (not START).
- Pull a connector off one of the injectors.
- Using a test light or multimeter on VDC, probe between a good chassis GROUND and both contacts of the connector. One and only one contact should have 12VDC.
- If this tests good, the injector is bad, the ECU (computer) may be bad (unlikely) or there is some other electrical problem feeding the ECU. More on that in another post if all else fails.
- If the above test is bad (no voltage on either injector connector contact), then pull the connector(s) off the double relay.
- All the following are tests at the connector(s). Using the diagram, put the ground side of your probe/meter on pin 85. With the ignition ON you should measure 12VDC at pins 86c, 88z and 88b. (Also 88y, but this is not relevant to this test.)
- If you have voltage at 86c and 88z, but not 88b, the relay is bad.
- If there is no voltage on 86c, then there is a problem with voltage making it from the key switch. This connection is actually daisy-chained from the coil, so test for voltage there. If none is found, the ignition switch or the the wiring in between is faulty.
- If there is no voltage at 88z, there is a bad connection at the positive side of the battery; a smaller solid RED wire should be found at the positive battery terminal.
- One other possibility is there is a bad GROUND to pin 85. You can test this from pin 85 to a known good 12VDC source, i.e. the battery directly.
- When you have discovered and fixed the potential problem, try the injector squirt test again before trying to start the engine; you may fix this issue but have other problems, you don't want to get fooled into thinking the injector circuit is still at fault.
Hope I covered it all. Give it a try and let me know what you find.
Rick
