runawaykinms

Hey Guys,

Ok, I don't know a lot about cars, but I am really frustrated and hope to find some help on this board. I will do my best to explain the problem and then what has been done thus far to fix it. I have included a summary of repairs at the bottom of the post.


About a year ago my car started to misfire. At that time I took the car to the Honda dealership and they replaced the spark plugs and the ELD(Electric Load Detector) system. For a month or two the car ran fine and had no problems.

After a couple of months the problem returned. I took the car to a small private shop to investigate the problem. The misfire code was on #2. Therefore, they swapped the coils on #2 and #4 to see if the problem/code moved. They didn't charge me and told me to come back in a few days when it happens again. However, to my surprise the car ran fine for a couple months.

Eventually though the problem returned. This time though the misfire was on a couple different cylinders. At that time the mechanic replaced the two problem coils. Within a couple days the problem continued. I took it back to the shop and the other two coils were replaced.

The vehicle ran fine again for a few weeks, but the problem returned. I took it back to the mechanic and this time they replaced all the fuel injectors. This did not fix the problem and I brought it right back.

When I brought the car back the mechanic checked the compression on the cylinders and those came back good. He then decided to replace the coils again to see if that fixes it. The car ran fine for another month, but the problem is now returning.

Summary of repairs:

1. Spark plugs replaced by Honda Dealership
2. ELD system replaced by Honda Dealership
3. Engine Coils replaced
4. Fuel Injectors replaced
5. Compression tested with positive results
6. Engine Coils replaced again
7. ??????????????????????????????

What else can I do? Does the above description suggest any certain causes? I find it odd because the problem comes and goes. It seems like once something is fixed the problem goes away for a little bit and then comes back later. I would be thankful for any suggestions.

Thanks!!!

emich

No one suggested cam and crank sensors?

mikey1

is your check engine light on? or has it ever come on?

if so, what are the code numbers?

when you remove your spark plugs what do they look like?

take pictures of the plugs removed, and number them for each cylinder, don't get the plugs mixed up

runawaykinms

Nope, not yet.

runawaykinms

The check engine light came on each time I took it to the mechanic. The codes have included:

P0301
P0302
P0303
P0304

I want to say he told me there was also a P0300 code in there too, but I can't say for sure. Most the time when he described it to me he only said things like, "You had a misfire on cylinder #2 & #4."

Reference the spark plugs, I can try that too. However, when the mechanic looked at those he knew someone(Honda Dealership) had changed them because he said they looked good.

runawaykinms

Update:

The car ran fine for a few days with no misfires. However, today they started again and the check engine light came back on.

I have noticed that the misfires usually occur and are worst when I accelerate. One of the main places it occurs is when I am merging to get on the highway. Also, when I let off the gas at that time it stops or corrects itself?

Could it be fuel pump related?

ezone

IMO no.

I'd expect high fuel trim numbers and a marked difference in O2 sensor response (low) during hard acceleration, maybe accompanied by a code P0171 fuel metering lean--- if the fuel pressure were too low.

One could actually check fuel pressure if they thought it might be an issue , but if I did not see those telltale clues in the live data stream from the computer, I would not be looking at fuel pressure..


Ever lost your gas cap? Water in the tank?

runawaykinms

I thought I would give an update for my misfire problem. That way if I am able to fix the problem this thread might be helpful to others in the future.

Update:

I talked to a guy who knows his Honda cars. He told me that he has heard of similar scenarios and because I have already replaced all the things above, he suggested I clean both the EGR valve and the EGR passages.

I did a little research on that, and have found others who stated that the build up or clogged up passages for the EGR valve and passages was causing misfires and by cleaning them out really good it fixed their problem.

Therefore, I have a guy coming over in a couple days to clean them out and see if that helps solve the problem.

I figure at this point, I have tried so many of the normal solutions(spark plugs, coils, injectors) without success, I will give it a try.

runawaykinms

@Ezone

Nope, never lost my gas cap. There shouldn't be any water in the tank.

runawaykinms

Update:

Ok, reference my above post about the EGR issues I had a mechanic come by today and fix three things:

1. Clean the EGR Valve
2. Clean the EGR passages that were backed up with carbon build up. Two of the holes were blocked.
3. Replace the intake manifold gasket


I took it for a test drive and seems to be running well. I hope this was the problem that was causing my never ending misfire. If it comes back I will let you know.

Dziri

I know it's an old thread, but did clearing the EGR passages in the intake manifold fix the problem?
I'm having a similar problem (cylinder2 misfire, check engine light flashing) and 2 different mechanics couldn't fix.
2003 Civic EX 5MT, 141,000 miles.

runawaykinms

NDNV

Strange that no EGR malfunction codes (P1491 or P0401) popped up but I have read that this does indeed happen.

mac25

That is odd since I've had my egr blocked intentionally for a few years with no issues, other than the cel.

Maybe if flow is detected, even if it is low egr flow, the ecu selects a certain fuel map; and if a code is on it selects another?

ezone

P1491 and P0404 won't be caused by clogged passages

P0401 won't set until the EGR passages are extremely restricted, for all I know that could be after the last individual passage is 90% clogged

A single cylinder misfire will happen --mostly just in cruise mode--- when the EGR valve opens and 3 out of 4 EGR distribution passages are clogged. The cylinder that's on last open passage receives far too much EGR and it snuffs the flame out. (could also be 2 and 2)

--mostly just in cruise mode--- This is why reading Freeze Frame data is critical

mac25

Ah that makes sense, the @ezone .