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Symptoms are intermittent stalling and then hard starting afterwards. Sometimes it has to sit for 3-5 minutes before it will start. The code makes perfect sense, I just don't know enough to begin troubleshooting.
What does it mean? What part is bad or in need of cleaning?
KOEO 95 means that, right now (during the test), there's either a full open or a short to ground in the fuel pump circuit. A CM 95 (CM codes are after the separator pulse), means that at some point in the past (perhaps one of those stalls/no starts), there was a full open/short to ground in the fuel pump circuit. A CM code without an accompanying KOEO code also indicates an intermittent fault (so you would need to adjust your diagnosis accordingly).
Begin troubleshooting by obtaining a wiring diagram, then work through the fuel pump circuit until you locate the break/short in the fuel pump wiring. Pay particular attention to the fuel pump relay, the inertia switch, the fuel pump fuse/fusible link, and any connectors.
Yikes! I was hoping there would be a simple answer but I guess it comes with the territory when you buy a used car. The engine was replaced about 64K miles ago and it appears that there were a hand full of wires and connectors that were "extra" Tough knowing where to start when you have a mess like that.
It was after the separator pulse on the test for sure. Would that narrow down the problem any?
Last edited by manasota; Oct 15, 2005 at 07:57 AM.
Not really. If you pass the KOEO test (11 before separator pulse) and get a CM 95 (after separator pulse), accompanied by an intermittent stumble/stall, the msot likely conclusion is that you have an intermittent break in the fuel pump circuit. An intermittent is harder to track down that a good hard break in the circuit, but it shouldn't be overly difficult. With your wiring diagram as a guide, put the + lead of your voltmeter at the inertia switch, - lead to any good ground, and watch the voltage when it stumbles/stalls. If you see the voltage drop off, then you know the break is upstream of the inertia switch (move on to the relay). If the voltage doesn't drop off, then the break is downstream of the inertia switch (move on to fuel pump connector).
If all this troubleshooting is really beyond what you're comfortable with, you could take a wild guess and replace the fuel pump relay. Relay isn't overly expensive and there's a reasonable chance that it is the offending part.
The problem is recreating the symptoms. I can drive it for days on end without it stalling. After it starts again I've never had it stall out twice in one day. It will stall under normal driving conditions and it instantly cuts out almost as if it were another type of electrical problem.
I haven't ran it much lately. It's more or less become my dedicated boat tower. I'm only 1/4 mile from the ramp and it does a great job putting my skiff in and out (especially out!). My son has turned driving age and he's hinted that he'd like to have it so I want to work the bugs out.
Thanks for sharing your knowledge!
Last edited by manasota; Oct 15, 2005 at 07:33 PM.
The problem is recreating the symptoms. I can drive it for days on end without it stalling. After it starts again I've never had it stall out twice in one day. ...
That's exactly why it can be so difficult to diagnose intermittant faults like this one.