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| Error code 31 - pressure sensor AND crazy timing; Low power on take off, Code 31, Crazy timing | |
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| Tweet Topic Started: Oct 21 2011, 12:42 AM (1,739 Views) | |
| BoneYardCustoms | Oct 21 2011, 12:42 AM Post #1 |
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Hey guys, hoping for some advice. This is the 6th Geo Metro my family has owned and the first time I have encountered this issue. Hopefully I can explain it clearly. Currently I am driving a 95 Geo Metro 2 dr with an automatic. The car has no power on take off, sometimes I think it would be better to push start it at the lights. Once it builds up some rpms it gets a little better then when it hits around 2k rpm it comes to life and I have great power. It's even worse when the AC is on. I put a timing light on it and the timing jumps around constantly, just freaking out. It sits around 8 degrees advanced and then jumps 5 degrees either side of that spastically. And it jumps around without me touching the throttle, just sitting there at idle. When I turn on the AC it kicks it up so far advanced that I can only see it for little flashes when it is jumping around. If I get it up to 2k rpms it will start to settle down but is still not steady. It's just odd, it's almost like driving a two stroke, no power at the bottom end and then it hits it's power band and I'm driving a hot rod. I have been digging around on the internet like crazy and feeling like I'm going in circles. At first I thought it might be the ECM because of the timing jumping around but then I found several posts that made me think differently and those things are expensive, so I would rather not start there. I pulled the codes and it's reading an error 31. Tomorrow I am going to pick up a new MAP sensor and start there but could that be messing with the timing like this? I've also already replaced the plugs, cap, rotor and wires. I haven't checked compression yet but going off the timing issue and the fact that it has lots of power once the rpm's build up I wasn't thinking this was the culprit, it also doesn't burn any oil at all. Thanks Guys, Shawn |
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| Bad Bent | Oct 21 2011, 02:20 AM Post #2 |
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Facetious Educated Donkey
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Welcome to your new forum, BoneYardCustoms! The timing mark moving around may be because you didn't jumper the ECM socket? Click on the link: Timing if you wish. Usually the sticker on the hood will say what is done to check the timing. Socket location: ![]() If that does not help then it may be the keyway that holds the crankshaft gear on. Which may be related to the possibility that the 0 low end power is because the timing belt jumped a gear and is one tooth retarded. Click on: Timing Belt Replace and Repair. This will necessitate loosening the Alternator, taking the belt off and the water pump pulley and the crankshaft pulley, then the timing belt cover and aligning the timing marks. I'm slow so it takes me 1.5 hours to replace the timing belt. If yours hasn't been changed in a while maybe it's time? It could be stretched due to age.Next thought is what is your idle? Is it steady? Is it high? If idle is high it may not be your MAP sensor but a vacuum leak. Before you buy anything (else) we have tests. Too Much Fuel post #27 Geo Won't Start post #37 Loss of power at 30 mph post #4 May I ask what were the last 3 things done to the engine and electronics? |
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| BoneYardCustoms | Oct 21 2011, 12:49 PM Post #3 |
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Bad Bent, I think you solved the great mystery of the freaked out timing. We have owned 6 of these but they have rarely given us any trouble. Never had to check timing so I checked it like I did all the other vehicles.......never jumped the ECM socket. Never even thought of looking into that so I'll just take the Dee Dee Dee badge on that one and say THANKS. Idle is a longer question. This problem of no power on take off has been going on for almost a year, it started out where the problem was only when the AC was on, turn that off and it ran like a champ. So I would just turn the AC off when the light turned Green and turn it back on once I hit about 25mph. Now it has gotten to the point where the AC almost stalls it out and it has No power on take off most of the time. I only drive about 10 miles a day so it's been easy to ignore but it's gotten to the point where I finally decided I need to take care of it or I'm going to die in this thing. At first the Idle was steady and smooth and without any load the motor revs smooth. Over the past month it has gone a bit downhill though and now it idles like one of the cylinders isn't giving it's all but it still revs up smooth. I am thinking this has to do with a fouled plug though. I have new plugs but don't want to burn through them until I figure out some other issues (already tried this). I will look over the hoses for a vacuum leak. Rubber hoses are a lot cheaper then the MAP sensor. Haven't bought the MAP yet, was hoping for some other options first. I will look into the timing belt and the other posts you suggested all worth digging into. Will jump the ECM and recheck timing. I currently have 130k miles on the car and really haven't done much to it. I changed the Plugs, cap, rotor and wires and that's been it. Originally thought that might be the issue, that was a year ago, it helped slightly but didn't solve the issue. When that didn't resolve the issue I started ignoring it and haven't touched anything else on it since which brings me to where I am at today. I just don't pull out in front of large trucks, especially ones driven by my wife. Thanks! |
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| BoneYardCustoms | Oct 21 2011, 05:32 PM Post #4 |
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Couple other things to add. I bought the car from a friend who was the original owner. It had a High Idle issue he couldn't solve. Ended up being the idle bump for when the AC kicks on. The plunger stuck all the way open running the idle way up. I just removed it and have been running it that way since. Not sure if that missing might be causing some of this issue. Also, at light to medium throttle is where she runs well. Best way to get this problem to come out is to give it Full Throttle and the motor bogs and falls on it's face. |
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| Bad Bent | Oct 21 2011, 05:49 PM Post #5 |
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Facetious Educated Donkey
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You are welcome. Well, at 130,000 miles the timing belt and compression are really going to be suspect.Click on How To - Compression Test. I've been blessed and not had any issues with such items as the IAC (Idle Air Control (IAC pic)) or the hoses associated with it but it could be your issue. One that comes to mind is a blocked brake booster hose. If there is a blockage it could be some vacuum hose. My recent issues included less vacuum to my distributor which I solved by spraying carb. cleaner in the two hoses, start it and drive off. Repeat as necessary. One test you can do is get a vacuum gauge, hose and "T" and "T" it into the MAP vacuum hose at the Throttle Body. It should be at 21" and not fluttering (valves). Has the catalytic converter ever been changed? It could be slowly clogging.. You can pull the O2 sensor out of the exhaust manifold and see if runs better. Much louder, but better. My wife drove trucks in the Army.
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| Bad Bent | Oct 21 2011, 05:54 PM Post #6 |
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Facetious Educated Donkey
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That would be a good thing.You might try cleaning it with carb. cleaner. Little blue thingy as mentioned in line 3 of the post above? IAC? |
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| Woodie | Oct 22 2011, 05:01 AM Post #7 |
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130K on an automatic almost certainly is due for a rebuild. Get your compression tested, warm engine, all plugs out, throttle wide open. |
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| BoneYardCustoms | Oct 22 2011, 12:37 PM Post #8 |
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You guys are Awesome. I will check on all of the above suggestions and get back with you guys this next week with some numbers. I have been wondering about the cat. I know it might not be the cause but I doubt it's helping either. Thanks again! |
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| BoneYardCustoms | Dec 8 2011, 01:38 AM Post #9 |
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Just an update. Been a crazy couple of weeks so I haven't been able to do much. I checked compression, running 150,140,140,150. Not perfect but not low enough to cause this headache. My IAC was ruined so I got a used one off of Ebay and will get it put in next. I'll check the CAT this weekend and the vaccum at the manifold. Getting there, slowly but surely...... |
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If yours hasn't been changed in a while maybe it's time? It could be stretched due to age.
That would be a good thing.
1:58 PM Jul 11