Okay, my Alfa Amici - I am really, really stuck.
I thought I had the solution with a bad ground but now my poor spider completely refuses to start.
Symptom - turns over normally and strong when I turn the key. However, sometimes it was hard to start and would go after several attempts, sometimes catching only as I was letting go of the key.
Now, it is completely non-starting - it turns over strong but I have a no spark/no fuel situation.
Where my retirement fund has gone:
New battery, new starter, 2 new flywheel sensors, new cap/rotor/plugs/wires, new fuel pumps, new fuel lines, new silicone hoses in engine bay
What I've checked:
Battery strong, at least 10.5V while cranking
Flywheel sensors giving normal resistance, even back to the ignition ECU harness
Ignition ECU harness check diagnostic all shows appropriate resistance/voltage
Followed the L-Jet diagnostic to a T and everything checks out
Cold start injector does not squirt at all during attempted start up
Fuses all conducting, appear to be in good condition (despite being old bullet type)
Fuel pump fuse was upgraded and appears to be normal
Both the fuel pump and main relays click when the ignition is turned on
Things I've noticed:
If I disconnect the fuel ECU harness and turn the ignition to on, both fuel pumps run normally and continuously
Last week when I last wrote I had cleaned the ground by the ECUs and it started right up (that was the last time it started)
After it starts, even when it was hard to start before, it would then run fine - no issues. It's only a start-up problem.
Questions I have:
1) Can you think of anything else to check?
2) My understanding is that the flywheel sensors would give a no spark/no fuel situation but they check out. Anything else that would make this happen?
3) I know an electronic distributor removes the need for the ignition ECU. If the ignition ECU is faulty, would that solve my problem? (and if so, how does it tell the main ECU to start pumping fuel?)
4) If the problem is the main (fuel ECU) would that give these symptoms?
5) The ignition switch is also an obvious suspect given that before this problem became really bad it would start just as I was letting go of the key. I bypassed it and the symptom was the same, though. Would it turn over normally even with a faulty ignition switch?
Thank you in advance - I am completely stumped this time.