My 1996 Honda Civic EX is misfiring and rough to start when warm. When its cold is normally starts fine and doesn't throw a CEL. Engine code is P0302 which is a misfire in cylinder 2. I've changed plugs, wires, cap and rotor. While the car is running and warm if i pull the #2 plug wire the idle doesnt change at all but i can hear it sparking inside. Im out of ideas, any help is very much appreciated!

 

Also while driving the CEL will switch from being Solid to Blinking.

 

The top spark plug is cylinder #1, the bottom is #2

 

Pulling a plug wire like that is very hard on the ignition. The best method to verify spark is to get an High Energy Ignition (HEI) spark tester. They are cheap and they guarantee accurate results.

Warm up the car, turn it off, hook up the tester and start the car. See if you get a good quality (white) spark in the tester. If you do, then it's some other issue and I would be leaning in the direction of a leak down test and compression test to see if it's a compression issue in #2.

If you don't get spark on #2 but do on all others, I would switch wires around and see if you get the same results (rule out a bad wire). Same results then you have to test the ignition control module (coil problems would prevent spark on all four if I'm not mistaken).

Hopefully this gives you some insight on some of the diagnostics you are in store for.

#2 appears to be starting to dry foul (if it's not wet). Dry fouling is caused by fuel not burning, which can be caused by low compression, lack of spark or too much fuel (burnt valves, bent valves, bad rings, no or intermittent spark, stuck open injector).

 

Compression test the cylinders and check whether injector 2 is malfunctioning.

 

I ran the car for about 5 minutes, then pulled the #2 plug and it was not dry. I just replaced the ignition coil in the distributor and im about to change the igniter.

 

Just to clarify, by wet I mean coated with oil, which is known as wet fouling.

The black carbon building up and doesn't look to be oil soaked is known as dry fouling.

 

That would make sense.... Sometimes i amaze myself at how dumb i can be lmao

 

We all start somewhere. Just like RonJ here can run circles around me.

Many different levels of experience here at H-T aimed at helping each other out when we can.

 

Ya very true. So i just switched out the ICM from the distributor and still didn't make a difference, next to check injectors and pray thats the problem...

 

 

I just checked the injectors resistance and all four were 15.7. Is there a way to check the connector to the injector without a noid light?

 

No but if it was stuck open it would have a significant difference in resistance compared to the other 3.

Compression check and more than likely #2 is low in compression. Leak down should give an indication of where it's losing compression if the compression test shows low numbers.

 

Did a compression test, #1 #3 and #4 were around 120, #2 was 60. Put oil in the cylinder, redid the test and the #2 cylinder shot up in pressure, so my rings are bad.... Anyone know of a good rebuild kit for a d16y8? lol

 

What did it shoot up to?

 

Over 220psi

 

IF anyone knows of a good rebuild kit let me know, i may or may not rebuild it, not sure yet.

 

60 to 220 psi while all the others are at 120 psi doesn't sound like the test was done properly.

120 sounds like cold engine numbers not after the car is warmed up. And 220 with oil doesn't sound like the throttle was wide open.

Dry or wet testing is done best with the engine warmed up completely and you crank the throttle to wide open with the injectors unhooked and both plugs removed from the distributor. So no spark no fuel, warm engine, WOT.

I believe 120 is below minimum for the engine to run that is another reason I believe you did the tests on a cold engine.

 

^^^Agreed. It should come up but not that much, and only in one cylinder?

 

He probably didnt test all of them again.

1. Heat up your car nice and good
2. Pull the ECU fuse under the hood
3. Take out the spark plug from the cylinder you're testing, insert compression tester.
4. Crank for up to 10 seconds, until the needle in the compression tester stops moving.
5 try again after putting 1 tea spoon of oil in the cylinder, actually measure it dont eye ball it.

do that on all 4 cylinders.

you're better off not rebuilding the block, the 6th gens are usually easy to come by in junk yards with bad automatic transmissions. Rig up a starter switch in the junk yard, and try compression testing the engine there before you buy it. It'l be way cheaper to get a good block that way than doing a factory-spec rebuild, 100-500 for the short block or the entire power plant with transmission and accessories, vs 1,000+ at a machine shop

 

I'll have to redo the test when i get back in town on sunday.

 

Why does the throttle have to be wide open, just curious?

 

Quoted from a Miata forum, explains it very well.

 

Redo the test and report

 

I've redone the test and here are the numbers. #1 125 #2 90 #3 130 #4 145. Wet test on #2 was 120.