Date: Wed, 11 Mar 2015 14:17:19 -0700
Reply-To: John Goubeaux <john@UCSB.EDU>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Goubeaux <john@UCSB.EDU>
Organization: UCSB
Subject: No Start Scenario
Content-Type: text/plain; charset=utf-8; format=flowed
Hi Guys,
2WD 90 2.1
I'm trbl shooting a NO start scenario.
Starter cranks over the engine just fine. I Do NOT hear the FuelPump pre
cycle - at all - when ignition goes to the ON stage SO I headed in that
direction and used the FuelPump Relay diagnose from this page:
http://www.vanagonparts.com/fuel_pump_relay.html - which BTW looks like
it is derived from the "Dijifant Guide"
So starting with the FP Relay:
I pulled the Relay
I confirmed that # 30 has battery current BUT # 86 does NOT
I jumped #87 with #30 and FP whirls away ( so FP does work )
I checked continuity with #85 to ground with engine cranking and I have
continuity ( So ECU is going to ground )
So, what does the fact that I do NOT get battery current from # 86 mean
? And is this from the Ignition switch? ( or should I have left the
relay plugged in while testing ?) There is No indication in the steps
other than to "diagnose the circuit". I'm unclear IF that circuit is
energized from the FI Relay OR the ignition switch. So this is where I
am stuck.
I've got a new ignition switch and relays on the way so can do some
swapping out AND intend to replace the ignition switch anyway as it IS old.
Can I assume that at this point the ECU and FP are OK and that it's
likely a relay, ignition switch, and or connections in between ?
Thanks for any advice
PS:I know there is a lot of info online already on this topic, BUT I've
yet to find a thorough diagnostic step by step with ALL the needed info.
-john
1. Check terminal No. 30 and terminal No. 86 of fuel pump relay for
battery voltage. If battery voltage is not present, check circuit
for short or open circuit.
2. If battery voltage is present, remove relay and attach ohmmeter
probe to relay box terminal No. 85. Attach other probe to ground.
Continuity should be present while cranking engine.
3. If continuity is not present, check for continuity between terminal
No. 85 of fuel pump relay and terminal No. 3 of ECU connector. If
continuity is present, circuit is okay but ECU is not switching to
ground. Replace ECU and install fuel pump relay.
4. If fuel pump will not operate, turn ignition switch off, then on.
Ensure battery voltage is present at fuel pump relay No. 87 for
about 5 seconds after ignition is switched on. If battery voltage is
not present, replace fuel pump relay. If battery voltage is present,
check voltage supply and ground circuit of fuel pump. If fuel pump
wiring is okay, replace fuel pump.