Multiple cylinder misfire

[Suter]

The problem started yesterday out of nowhere. 03 GTI, pretty much stock. I drove to work yesterday with out any issues, but after work, before I was even out of the parking lot I noticed the idle was rough. Ive had ignition coils go out, and that as my first assumption.

As I accelerated out of the parking lot, the car was pretty jerky and hesitant, and then I noticed the CEL was blinking. Checked it out when I got home, and I have 3 new codes, PO300 - Random/multiple cylinder misfire. Misfires are on 1 and 4. I switched coils 1 and 2 and erased the codes to see if the coil was bad, started it up, and same thing, misfires on 1 and 4.

Im pretty new to this engine and its a newer car than Ive ever owned. Most of the info I found was in the 1.8T forums, and usually pointed to software issues or vacuum loss, but all the info was vague or directly related to the 1.8T.

Could anyone offer me a little direction?

[orau22]

spark plugs?

[blevs17]

im having the same problem with mine. i have just a cyl 1 misfire. new plugs and coils, even a new injector. and still have the problem. interested to hear how yours turns out.

[Suter]

I just replaced the spark plugs and still no luck. I had tried unplugging the battery before as well thinking it might be an ECU problem or something that might reset.

I honestly dont have the slightest clue this time around. Im puzzled how it just randomly started upon a startup with no prior issues.

[ern79]

Check compression

[shanegilmour]

Before you replace anything unplug your front oxygen sensors at the firewall. I had my car in the shop and they couldn't figure it out so when I got it back home I tried this and that was the problem.

[Suter]

Well guys sorry for being in and out of here. I had originally swapped the coils and reran the codes and was still getting misfires the same cylinders. I later checked manually by unplugging them and found 2 bad coils. So I replaced them and was good for a few days. Now today I start her up and have 8 faults.

P0300
P0301
P1364
p1361
P1355
P1358
p1370
p1367

doesn't seem to be running as rough, but is still pretty choppy. I'm looking for a little more insight before I get home in the morning

[Suter]

I will try disconnecting my o2 tomorrow and see what that does for me. Havent had a computer available, browsing and posting on a phone is the worst. doing some research on the new codes at home now though.

[Holmes741]

Has to be the amplifier. Ignition coils do go bad, but not two at a time by themselves. I've never heard of this problem before, keep us updated.

[rajvosa71000]

Sometimes i get missfire codes on my supercharged GTI, and while i replaced new coilpacks and pugs i would still get it sometimes, it happens when Im at wot, cel would blink but go away aftet a few seconds.
Now, my theory is, my timing its advanced at 1.25 degrees and while on despot 91 oct. It runs lean, or its my lwfw, giving false load reading to the ecu. I asked Jeff from at that time C2 motorsports and he asked me if i had lwfw, and that it would give ecu false load reading or someting like that, cant remember.

Sent from my HTC Sensation 4G using Tapatalk 2

[Suter]

Has to be the amplifier. Ignition coils do go bad, but not two at a time by themselves. I've never heard of this problem before, keep us updated.

Amplifier? Sorry, again, Im new to this new of an engine. I just replaced all the spark plugs, and it looks like cylinder 1 has burned up another coil. Swapped it to cyl2 and checked and yep, the coils dead. Now Im no longer getting a constant CEL that flashes on acceleration, but just a flashing CEL on acceleration occasionally. The light goes off though, and Im not able to check the codes for it.

[Suter]

Sometimes i get missfire codes on my supercharged GTI, and while i replaced new coilpacks and pugs i would still get it sometimes, it happens when Im at wot, cel would blink but go away aftet a few seconds.
Now, my theory is, my timing its advanced at 1.25 degrees and while on despot 91 oct. It runs lean, or its my lwfw, giving false load reading to the ecu. I asked Jeff from at that time C2 motorsports and he asked me if i had lwfw, and that it would give ecu false load reading or someting like that, cant remember.

Sent from my HTC Sensation 4G using Tapatalk 2

lwfw? Although my motor is basically stock so Im not sure if it would pertain to me anyways.