I just did a 2 hour drive today and when I was heading back the car started to misfire going up hill at 65mph the cel started to flash and then It was fine. Only seems to do this under load I replaced cap and rotor the plugs and wires are a couple months old. Any ideas?

 

Pull the CEL codes.

 

Misfire code p1399

 

^Brands?

Did you replace the fuel filter?

What engine?

Bone stock Civic?

 

Valuecraft? Stock motor 1.6 non vtec haven't done filter this only happens in 5th gear at 65mph or at least that's when it's really noticeable and the cel starts to flash until I let off

 

Install the Honda-recommended properly gapped NGK spark plugs.

Replace fuel filter.

Then go from there.

 

Plugs are ngks and new I will try filter next

 

Did you verify correct gap on the plugs?

P1399 is a generic random misfire code. If the CEL still turns on or blinks after replacing the fuel filter, then next pull the codes by jumping the service connector. Post the codes you recover using this method.

 

Alright I'm not sure how to jump the service connector?

 

Po304 p0300 p0302 are the codes I pulled this morning

 

If you have new plugs, wires, cap, rotor and fuel filter(which honestly I don't think it's your issue), then go ahead and perform a cold and hot compression test and leakdown test.

 

Haven't done fuel filter yet. Would a bad distributor do this?

 

Just did resistance test on wires two were in low 4s and the other 5s if that make sense

 

It would but considering that it only happens when under load, I'm thinking its something more mechanical than electrical. You can swap one out, but it won't hurt to do a compression test to see the condition of the engine.

 

Did you gap the spark plugs?

Have you inspected the inside of the distributor? Did the rotor screw fall out? Is it loose? Is there oil or red dust inside the distributor? Is the inner dust cover missing? Post pictures.

Given the misfire is 2 specific cylinders, the suggestion to do a compression test is reasonable, if you rule out a trivial ignition system issue.

 

Rotor screw is good. There was a no oil or anything inside the distributor I did one compression test on cylinder 4 and it was 120

 

Why are you avoiding answering the question about gapping the spark plugs?

Compare compression in all 4 cylinders. Do you know how to do a compression test properly?

 

There gapped at 40 I'm not avoiding it I know there fine just spaced it. Well I did one cylinder and somehow managed to break the compression tester taking it out.. Yeah just my luck

 

The proper gap is 0.043".

Answer all questions or this thread gets locked. From the forum Rules:

Click the forum Rules link in my signature. Read the rules very carefully before you make anymore posts or threads in this forum.

 

I answered all the questions relax don't need ur attitude