Massive Power Loss..

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Oct 6, 2018 | 11:32 PM

Sgtusmc98

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Massive Power Loss..

I just replaced my alternator and vapor canister. Car seemed to be running fine, it was a little rough in idle but I saw on another post here that sometimes it takes a little while for the computer to reset after the battery is disconnected so I wasn’t worrying about it yet.
Ran about half a tank of gas through and suddenly I lost power, it got my home but had to use 3rd gear instead of 5th, the car barely can get moving from a full stop and sputters. Everything thing appears to be intact. It did have similar power loss earlier when the
alternator belt broke but it had battery lights and red engine lights come on. It does occasionally flash the yellow engine light but according to the previous owners, my in-laws, it always did that, the Scion mechanic told them if the belt ever slipped the light came on.

Ideas?

2005 Scion xA

Last edited by MR_LUV; Oct 7, 2018 at 07:47 PM. Reason: tidy up

Oct 7, 2018 | 07:35 PM

MileHightC

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CEL? Trouble codes?

Oct 7, 2018 | 09:16 PM

Sgtusmc98

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Quote:

Originally Posted by MileHightC

CEL? Trouble codes?

I was planning on taking it to a mechanic but may have changed my mind, I may buy a code reader. So no, at this point I don’t have codes.

Oct 15, 2018 | 02:38 PM

Sgtusmc98

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Codes

Quote:

Originally Posted by Sgtusmc98

I was planning on taking it to a mechanic but may have changed my mind, I may buy a code reader. So no, at this point I don’t have codes.

I know previously when I posted I didn’t have much information. This is what I have now:

P0300 random/multiple misfires
P0303 misfire cylinder 3
P0304 misfire cylinder 4
P0138 O2 sensor Circuit high voltage

Thanks for the help!

Last edited by MR_LUV; Oct 15, 2018 at 03:00 PM. Reason: Image didn’t come through

Oct 15, 2018 | 03:19 PM

MileHightC

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I'd start by swapping the coil packs, clear the codes and see if you end-up with misfires on different cylinders at that point. See if you end up with P0301 and P0302.

Don't know what the mileage is but coil packs could be suspect...and I wouldn't call the CEL randomly flashing 'normal' even if the in-laws thought it to be.

Last edited by MR_LUV; Oct 15, 2018 at 08:27 PM.

Oct 15, 2018 | 03:24 PM

Sgtusmc98

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Quote:

Originally Posted by MileHightC

I'd start by swapping the coil packs, clear the codes and see if you end-up with misfires on different cylinders at that point. See if you end up with P0301 and P0302.

Don't know what the mileage is but coil packs could be suspect...and I wouldn't call the CEL randomly flashing 'normal' even if the in-laws thought it to be.

thanks I’ll try that, mileage is almost 170k.

Oct 15, 2018 | 04:43 PM

Sgtusmc98

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Codes

Swapped the first 2 and last 2 coil packs which I think would mean I put the potentially bad coil packs on the cylinders 1 and 2 which weren’t showing a misfire code.
After resetting everything the codes show confirmed the O2 sensor and pending for multiple misfire, and misfire for cylinders 3 & 4 as before.

Does that mean probably the plugs?

Last edited by MR_LUV; Oct 15, 2018 at 08:28 PM.

Oct 15, 2018 | 04:49 PM

MileHightC

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I'd say it's a good chance the plugs need changing since the misfires didn't follow the coil packs...plugs are cheap and easy and at 170K likely aren't going to hurt anything.

Oct 15, 2018 | 06:56 PM

Sgtusmc98

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Quote:

Originally Posted by MileHightC

I'd say it's a good chance the plugs need changing since the misfires didn't follow the coil packs...plugs are cheap and easy and at 170K likely aren't going to hurt anything.

Thanks, I’ll give that a shot as soon as I can get to a store.

Oct 18, 2018 | 02:08 PM

#10

Sgtusmc98

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Put new plugs in, still misfiring in 3 & 4 and high voltage in O2 sensor. Ideas?

Is there a way to see if the wires to the coil pack are hot?

or is there an access point to check resistance to make sure a wire isn’t broken?

Last edited by MR_LUV; Oct 18, 2018 at 03:49 PM. Reason: merge posts

Oct 23, 2018 | 11:09 PM

#11

RichBinAZ

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If you have a multimeter, you can check the igniter wires, comparing plug 1 with plug 4 and then 2 with 3.
Start by measuring voltages (safer) with the ignition on. Then turn ignition off and check for Ohms / continuity
Those pairs should be the same

Oct 24, 2018 | 12:19 AM

#12

Sgtusmc98

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Quote:

Originally Posted by RichBinAZ

thank you, I get nervous with some of these newer electrical systems. I think it’s going, not sure if codes messed up or I messed up but I checked the coils redneck style and pulled the coils while the engine was running to see which cylinders were dead then swapped and did it again, the dead cylinders followed so I put two new coil packs in and it seems to be working.