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| Engine Surging over 30 mph | |
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| Tweet Topic Started: Oct 26 2017, 01:48 PM (216 Views) | |
| MetroFarm | Oct 26 2017, 01:48 PM Post #1 |
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Fresh Fish
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My 1.0 has been driving just fine until yesterday it started surging and bucking bad while I was on the highway. It starts up great every time, and has no surging until I get around 30-35 mph. It doesn't die on me but feels like it might. I also hear a bit of a backfire in the intake (I think) while it's bucking and surging. I did a compression test and got these results for each cylinder. 1 - 120 2 - 95 3 - 140 I got the car last year and it's always burned a bit of oil and has gray smoke on acceleration for the first 5-10 mins, so I know it's leaking oil into the cylinders. I don't know if that problem finally came to a head or if it sounds like it's simply a coil pack or fuel pump. Here's a video of what it's doing: https://youtu.be/Bn5ratDgF6U Thanks! |
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| freegeo | Oct 26 2017, 02:02 PM Post #2 |
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How old are the plugs and what are they gaped at? |
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| MetroFarm | Oct 26 2017, 02:21 PM Post #3 |
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Fresh Fish
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I changed the plugs about a year ago when I got the car and they’re gapped to .039. Should I try new plugs/wires to start? |
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| freegeo | Oct 26 2017, 04:20 PM Post #4 |
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It may not hurt. If they look questionable, then it is best to change them out. |
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| freegeo | Oct 26 2017, 04:21 PM Post #5 |
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No recent work been done on the engine? |
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| geogonfa | Oct 26 2017, 04:35 PM Post #6 |
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First...Welcome to the Fun... With those compression #'s you're going to need a rebuild soon (did you do a wet and dry test?)... but, I would think that's not your only problem... Things to look for and check... Plugged up Catalytic Converter (you said you have been burning oil), Distributor cap/rotor, Fuel Pressure, Vacuum leak to the Map Sensor, TPS sensor... |
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| MetroFarm | Oct 27 2017, 07:36 AM Post #7 |
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Fresh Fish
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Thanks guys! I have not done any major work to the engine since I’ve had it, and I didn’t do wet vs dry on that compression test, that was just dry. I’ll check out these other suggested fixes (I didn’t even think about the cat converter!) |
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| MarkZ28 | Oct 27 2017, 08:10 AM Post #8 |
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May be a burned valve also. |
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| Moringa | Oct 27 2017, 08:15 AM Post #9 |
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Living BOT
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Good video! From THAT, I'd say that it's probably not an electrical problem. It seems to be either not enough fuel, or as already mentioned, a partial exhaust restriction. When's the last time the fuel filter was changed? On the subject of compression, the lowest cylinder is too low, assuming the test was done correctly. There is a specific procedure for these 1.0L tests. Typically, higher RPM tends to mask low compression problems. If it were me, I'd start out by checking fuel delivery related items. A long shot could also be a plugged up air filter. |
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| Woodie | Oct 28 2017, 05:30 AM Post #10 |
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If that compression test was done correctly the HIGHEST cylinder is too low. They're supposed to be 200 with 150 the recommended low. |
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| Moringa | Oct 28 2017, 03:29 PM Post #11 |
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Living BOT
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My wording could have been better. I mixed the "old school" way of testing, and results, with the "1.0L only" way of testing. I don't know what the minimum compression would be with the test done correctly, but the normal testing needs around 100 PSI, just to fire up and run. |
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| freegeo | Oct 28 2017, 04:20 PM Post #12 |
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Woodie stated what the factory min. is. 154.6 psi. Below that and you start to have driveability problems. Will they run lower than that, yes. |
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| MetroFarm | Nov 7 2017, 03:07 PM Post #13 |
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Fresh Fish
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Quick update on this: it turned out to be the ignition coil. Thanks for all the helps, guys! |
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