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Old 11-04-2018, 01:59 AM   #26
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Default 2007 impreza 2.5i with a weird "misfire"

2007 impreza 2.5i with a weird "misfire"
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Old 11-04-2018, 10:18 PM   #27
SamNFTY
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I'm gonna run this by my mechanic tomorrow, but a mechanic friend of mine says to check the volume of each cylinder. It's possible that in the remanufacturing process, they planed the heads or block so that one cylinder is slightly larger or smaller. Does this sound like it holds any weight?
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Old 11-04-2018, 10:33 PM   #28
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Quote:
Originally Posted by SamNFTY View Post
I'm gonna run this by my mechanic tomorrow, but a mechanic friend of mine says to check the volume of each cylinder. It's possible that in the remanufacturing process, they planed the heads or block so that one cylinder is slightly larger or smaller. Does this sound like it holds any weight?
That sounds like a load of crap.
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Old 11-04-2018, 10:43 PM   #29
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That sounds like a load of crap.
It's possibly a load of crap, but if it's right... Did you source your engine from ATK as well?
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Old 11-04-2018, 10:51 PM   #30
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Quote:
Originally Posted by SamNFTY View Post
I'm gonna run this by my mechanic tomorrow, but a mechanic friend of mine says to check the volume of each cylinder. It's possible that in the remanufacturing process, they planed the heads or block so that one cylinder is slightly larger or smaller. Does this sound like it holds any weight?
Quote:
Originally Posted by ubareddition View Post
That sounds like a load of crap.
Quote:
Originally Posted by SamNFTY View Post
It's possibly a load of crap, but if it's right... Did you source your engine from ATK as well?
The amount of "out of line" from HG deck to crank centerline to make an real measureable cylinder volume difference would create a ton of other issues (timing belt running off gear components, headers don't line up, intake manifold won't line up, etc., etc., etc.........).
So yes, I call major BS......
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Old 11-04-2018, 10:52 PM   #31
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The amount of "out of line" from HG deck to crank centerline to make an real measureable cylinder volume difference would create a ton of other issues (timing belt running off gear components, headers don't line up, intake manifold won't line up, etc., etc., etc.........).
So yes, I call major BS......
Well when you put it like that...
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Old 11-04-2018, 11:42 PM   #32
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Well when you put it like that...
Just my thoughts......
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Old 11-08-2018, 02:59 PM   #33
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Latest update. My mechanic is in touch with an ATK technician. They've had a similar issue, replaced the engine on warranty. ATK looked at the returned engine and determined that the reluctor wheel (which, correct me if I'm wrong, appears to be a part of the crank gear) was not the same size as the stock part. This could cause a faulty reading on the CPS triggering the P0303 and P0304 codes. I'll keep you posted on what they find out.
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Old 11-08-2018, 03:09 PM   #34
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Originally Posted by SamNFTY View Post
Latest update. My mechanic is in touch with an ATK technician. They've had a similar issue, replaced the engine on warranty. ATK looked at the returned engine and determined that the reluctor wheel (which, correct me if I'm wrong, appears to be a part of the crank gear) was not the same size as the stock part. This could cause a faulty reading on the CPS triggering the P0303 and P0304 codes. I'll keep you posted on what they find out.
There's only 2 crank gears for these cars as far a I know. One has 4 teeth and the other has 28 or so. So unless it was missing some teeth I doubt it was the wrong one. I don't even think it would run on the old style gear.
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Old 11-08-2018, 08:36 PM   #35
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There's only 2 crank gears for these cars as far a I know. One has 4 teeth and the other has 28 or so. So unless it was missing some teeth I doubt it was the wrong one. I don't even think it would run on the old style gear.
I spoke with the tech at ATK. The way he explained it to me, the part was the right part, but it may not have been manufactured to the right specs.
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Old 11-08-2018, 08:43 PM   #36
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I spoke with the tech at ATK. The way he explained it to me, the part was the right part, but it may not have been manufactured to the right specs.
I call bs. But regardless your getting a new motor correct?
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Old 11-08-2018, 09:23 PM   #37
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I call bs. But regardless your getting a new motor correct?
They're going to work with my mechanic to diagnose the issue before they ship a new engine. If it comes to that, then yeah I'll get a new engine.
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Old 11-12-2018, 06:52 PM   #38
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If everything in the cylinder is good then it's either the computer, wires to or from the crank/cam sensor, dirt between cam sensor and cam or someone swapped your cam sprocket, cam gear or damaged it. I've seen people swap cam gears from different engines when they do a lot of engine builds and that can cause a mystery misfire. I've seen it a lot on 2.5 to 2.0 swaps because they mix and match so many parts. On a straight 2.5 I feel like it'd be a dirty or damaged sensor/gear/sprocket.
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Old 11-17-2018, 05:11 PM   #39
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It appears that, when the timing belt went, it damaged my CPS. It wasn't immediately noticed when my mechanic swapped parts over to the new engine. Upon closer inspection he decided it was maybe damaged. He swapped it out and has been driving around with no CEL! I'll update when I get home and can pickup my car this week.
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Old 11-20-2018, 12:22 PM   #40
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Have you checked the CPS? It's been a few days since mine's been replaced with no CEL.
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Old 11-20-2018, 12:28 PM   #41
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Have you checked the CPS? It's been a few days since mine's been replaced with no CEL.
Yes. Tested. And replaced for ****s and giggles.
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Old 11-22-2018, 12:11 PM   #42
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CEL is back. It wasn't the CPS.
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Old 01-18-2019, 03:58 PM   #43
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ATK shipped out a second engine. Installed and engine seems to run smooth but 100 miles later the CEL is back. Same codes, P0303 and P0304.
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Old 01-18-2019, 04:13 PM   #44
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Update for you. Put in a new ECU in the car and runs great no cel. Been over 1000 miles so far.
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Old 02-14-2019, 04:58 PM   #45
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Update for you. Put in a new ECU in the car and runs great no cel. Been over 1000 miles so far.
That's what I was thinking it might be. Is it possible to reset the ECU?
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