#1
IP: 131.122.74.13
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Ignition Switch Problem?
The engine starts great when the ignition switch is turned to the start position, but immediately quits running as soon as the switch is released to the on position. I repeated this several times with the same result - sometimes holding the switch in the start position several seconds after the engine fires (the engine kept running as long as I held the switch in start). I will mention several "upgrades" I have made to the A4 recently, as they may give a hint to the source of the problem. 1) An Indigo Electronic Ignition was installed 1 month back (electronic module, coil, plug wires and plugs). The engine ran great after that with no problems. 2) Earlier this week replaced the existing electric fuel pump with a new one from MMI. Also, replaced the oil pressure safety switch. On the first attempt to sart the engine after these changes the above problem occurred. All wiring hookups were as before.
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#2
IP: 216.115.121.240
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Sure sounds like it's the oil pressure safety switch to me.
Test it with a light. Or, take it out of the circuit to isolate the problem. Russ
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Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1 "Since when is napping doing nothing?" |
#3
IP: 161.213.49.1
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+1 on this being a OPSS problem.
Other remote possibilites: Bad ignition switch You broke a wire somewhere while working on the engine recently. And: Are you getting power to the OPSS? Are you getting power through the OPSS? And so on. I think a session with a volt-ohm meter will give you the answer pronto. If you don't own one a $20-$25 analog meter will work fine - it doesn't need to be fancy. Even though it isn't Officially Recognized Protocol (or what ever you call it) I always fill the cavity in the OPSS with oil before I install it to be sure there isn't an air bubble trapped in it. May fair winds and calm seas be with you. TRUE GRIT Edit: Don't leave the key in the on position for a long period of time when the engine isn't running - it will fry the coil\electronic ignition. Last edited by JOHN COOKSON; 07-01-2011 at 12:33 PM. Reason: Spaced Out! |
#4
IP: 131.122.74.13
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I just got back from 10 days of vacation (no boat) and followed up your suggestions. First, bypassed the OPSS with a jumper wire - no start. Second, checked the power at the coil's positive terminal with the ignition in the on position- no power. Third, bought a new ignition switch from MMI, installed it and the A4 fires up and keeps on ticking. Thanks for your suggestions.
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#5
IP: 206.125.176.3
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thanks for the follow up! Bad ignition switch, huh?
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-Shawn "Holiday" - '89 Alura 35 #109 "Twice Around" - '77 C-30, #511 with original A-4 & MMI manifold - SOLD! (no longer a two boat owner!!) |
#6
IP: 24.152.131.220
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It seems we're reading more frequently of ignition switch failures. I wonder what is the most common cause and how it can be improved. The switches themselves are robust enough for the task so I expect they're being exposed to damaging conditions.
Two issues that come to mind are moisture and loose connections. As far as moisture, I think a spray shield would go a long way to help matters. For loose connections, an occasional tightness check and star lock washers on all posts should prevent problems.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#7
IP: 107.0.6.242
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Another thing to consider is what sort of loads we are putting on these switches. When you take one of these things apart it can be scary to see how little metal is really there for contact. The ignition switch should carry only the ignition circuit and nothing else. As we have seen on another thread, running an ammeter thru such a switch is also bad. A SPST toggle or rocker with a push button starter is the safest set up.
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#8
IP: 24.152.131.220
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Somehow I missed that thread. An ammeter (reading charging voltage) through an ignition switch? Key type or otherwise that's a new one on me. I'd like to see a schematic on how it would be wired - or is that mis-wired?
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
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