[DiZ]

Need some help guys.

I'm trying to track down a consistent Cylinder 1 misfire when under strong acceleration. It doesnt necessarily have to be at WOT.

Vehicle:
2020 Accord Sport 2.0t 10AT

Mods:
Full bolt-on
MHI Stage 2 Turbo
Flex Fuel
AEM Methanol Injection
Big Bore throttle body
Ported intake
Ported fuel rail
Ported fuel pipe


Things I've eliminated:

High pressure Fuel Pump
Low pressure Fuel Pump
Plugs
Coils
Injectors
Valves / Springs (ok & adjusted)
Compression Test is good
Leak down test is good
Boroscope with no sign of internal dmg
Tune

Any thoughts or suggestions would be much appreciated as I'm quite frustrated with the lack of a resolution thus far.

Thanks,

 

[Samuelx]

Seems like you have most/all of it covered? Any other error codes? Any vacuum leaks or o2 sensor problems?

 

[DiZ]

Hey Sam.

Absolutely nothing. Just the cylinder 1 misfire under acceleration. No other symptoms. No abnormal noises, etc..

 

[DiZ]

Update

While running a Boroscope into cylinder 1, we did a coolant pressure test. Lo' and behold there was some pretty blue coolant flowing in. So a blown headgasket is confirmed on the intake side.

I've already ordered ARP head studs for an FK8 and will go back with the OEM headgasket.

 

[taz69]

I was about to say blown head gasket. Every time anyone posts about a cylinder 1 misfire it seems to always end up being a blown head gasket. is yours a 1.5T or 2.0T?

 

[DiZ]

2.0t

 

[maroco92]

glad you found the solution! random question for OP: did you notice a difference with the big bore throttle body installed?

 

[taz69]

Did you have any mods done to the car?

 

[Fired00d]

Did you have any mods done to the car?

If you are asking the OP you may want to check out his 1st/original post.

 

[DiZ]

glad you found the solution! random question for OP: did you notice a difference with the big bore throttle body installed?

I'll let you know after I get to drive it properly.

 

[DiZ]

Did you have any mods done to the car?

Lol yeah, it's heavily modified. Somewhere around 500whp.

 

[taz69]

Thats a lot...

 

[KayGeeP]

If you are asking the OP you may want to check out his 1st/original post.