11 replies to this topic

[krue92]

Today I was driving my car and it was running great and pulling hard, but then all of a sudden when getting into boost it was bogging down or maybe misfiring. It is an FBO car running E85 with 26k miles on it. I don't think the plugs have ever been changed. Didn't throw any cel lights and runs fine at idle and when driving unless in boost. Anything else I should look at before changing the plugs? Thanks!

[krue92]

I just hammer on it in first gear and go through the gears its smooth as ever. If I hammer on it in a lower gear with the rpms low thats when it seems to stutter or bog down.  Got the service engine soon light once and it said misfire cylinder 2 when I pulled the code.

[Ian201]

So a P0302 my bet is that it is a plug

Edited by Ian201, 03 October 2021 - 12:20 PM.

[krue92]

Thanks... I just ordered plugs

[Ian201]

There is always a small chance that it can be a coil. If you want you could always switch coils on cyl 4 and cyl 2 and see if the misfire moves, it`s one way of checking. As you`re removing them anyway no more work involved.

[krue92]

Yeah that is a good idea.

[krue92]

I just don't want to have to take the intake manifold off again if it is a coil pack.

[Ian201]

Yeah i understand that but it`s the only way of isolating the coil if it is indeed the problem. My guess is  still the plug but obviously i can`t be 100% sure.

 

It`s an hours work to remove and install the manifold so it`s not that bad, that`s if you do it yourself and you have a garage where you can work you don`t even have to replace the gasket so no cost involved.

 

If your plugs were changed more than about 2-3 years ago and you run corn i still say plug.

[krue92]

I don't think they have ever been changed and been running corn for a long time. Hopefully the plugs clear it up. I was thinking it was probably due anyway. Thanks bro!

[krue92]

Changed the plugs and everything seems good now. How often should someone change plugs on a FBO car? Thanks!

[Ian201]

Good to hear it`s up and running again.

After every second year you need to change the plugs with normal driving/mileage.

Edited by Ian201, 21 October 2021 - 11:40 PM.

[krue92]

Thanks Ian!