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I am a ford technician and I am helping a friend with his galant. He is towing it down tomorrow. The only info I have is that it will crank and sound like its firing but will not start. I will check spark, fuel, etc but was wondering if any common issues can cause this? I do not have a scanner to monitor rpm signal from crank so I assume if no spark/fuel issue may lead to that. I also will check the timing belt. Just curious of any common issues. Thank you.
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Mitsubishis have a thing they do like this when there is a cam position sensor issue, where they will crank and fire once on the first turn and then just crank endlessly afterwards. Every ignition cycle it will do this the first attempt to start. Once the engine turns the second time and the computer still hasn’t seen a cam signal come around, it stops firing fuel/spark because it doesn’t know cyl1 TDC position.
I have verified no injector pulse/spark. I was looking for a way to test crank sensor and found a site that wanted me to check power and ground at the connector, I have both. They made it easy with the connector coming out of timing cover. I’m going to check and see if the signal pin shows anything other than the 5 volt reference. If it stays at 5v and doesn’t change that should indicate a bad crank sensor. If it does change I will look into the cam sensor. Is there any good way to test it.
I did not see a stand alone crank sensor. I assume it is part of the dist?
This is not helping with your Q, but I had 96 Galant and 3 more Mitsubishes.
My honest suggestion to you is wear cut resistant gloves while working on those cars. They have the sharpest edge sheetwork I ever encountered. I had COUNTLESS cuts on my hands any time I did anything on those cars.I really can’t offer any more car-specific advice than that until I can get to work and look at some service information and wiring diagrams. I can’t remember the last time, at least 3 years since anyone’s brought a mk7 Galant in for work. What is normal for Mitsu on crank and cam sensors is to have it be 3 wires. Ground, 5v power, and square wave signal. You really need a lab scope to diagnose the signal circuit properly. Power and ground can be checked with a normal multimeter or power probe, but those tools will not show anything conclusive on the signal circuit because things happen so fast. You might be able to tell that it’s doing something but you can’t really see it. If it does nothing, it’s hard to tell if it’s happening too fast for the meter to pick up or if it’s actually dead.
If you’re going to be dealing with this thing a few days, let me know and I’ll investigate a bit more at work tomorrow. It’s going to be a snow day anyway, I’ll have time to spare.
If you could that’d be great. I don’t have access to labscope at home. I just want to be sure I am right, this guy is a really good friend/customer of my side work and always fixes everything. Thank you.
I should also add where I read what to check it advised turning engine by hand and observing dc voltage while back probing signal wire. If it comes off 5 volts the sensor is seeing a reading and not to condemn the crank sensor. I am no import expert but have fixed quite a few. I do appreciate the advice.
The cam sensor is built into the distributor, The signal wire is the brown/green wire, power is black/red, ground is black. Signal wire on the crank sensor is Black/yellow. There is a trigger wheel for the crank sensor mounted behind the timing belt sprocket. It’s possible for that to come loose, and it’s somewhat common. If you have a crank signal problem, suspect that and pull the timing cover to look at that as part of diagnosis.
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