My 1998 Honda Accord 4 cylinder LX with 249K miles runs rough at approx.2200 rpms. Once I get past that point, engine smooths out. If I hold it at 2200 rpms, then check engine light will come on and flash. The code(s) came up as random misfires.

I changed cap, rotor, spark plug wires, and spark plugs but no change in performance.

As a test, with car engine cold, I disconnected VTEC solenoid wire and engine ran rough at any rpm/speed.

Any ideas???

 

Does it run fine at every other RPM? If it runs rough from idle to 2200rpm most likely vacuum leak and/or egr. Did you use OEM plugs/wires/caps/rotor?

Check:
ignition timing
EGR

@250k miles, when was the last time you had the timing belt replaced?

 

Timing belt and water pump at 210k.
Smooth above 2200 rpm definitely.

I cannot get a wrench on either bolt of EGR valve. The valve body is too wide
So it interferes with socket wrench. Any advice?

Thanks in advance.

 

Yes I used OEM parts.

 

Take some good picts of the EGR and post them up.

Is your EGR vacumm or electronic controlled? If it is vacuum controlled you put a mitty vac on and apply vacumm and see if it makes any changes.

On some EGRs you can put your fingers on the plunger and manually move them to test it.

Did you look for any vacuum leaks? There are tons of little hoses for you to check. A good auto repair shop will put a smoker machine on your intake to find it. For a DYI you might get lucky just looking for it or some people use starter fluid and spray a little mist around the hoses to see if it raises the rpms. Good luck. I always hated looking for vacuum/EVAP leaks.

 

 

It's a electronic controlled egr valve. My isssue now is I cannot remove the EGR bolts. I can't get a socket wrench on either of the 2 bolts.

I don't believe I have a vacuum leak though.

Let me know what you think.

 

 

I'd be more worried with the egr port being clogged than the egr valve.......

 

Thanks for the suggestions. I installed the spark plug wires from my 2002 Accord's onto the 1998 Accord and the problem went away. I reinstalled the new wires and the problem came back. So, it looks like the new wires are not working properly. Parts store said I can exchange them but it is snowing here in Ohio. So, I will try tomorrow.

Thanks for all the inputs!

 

A clogged EGR port should not cause drive ability problem. A clogged EGR will cause drive ability problems.

A clogged EGR port might cause your car to fail smog because of high HC.

 

For the EGR bolts try an elbow or a crow's foot on your socket extension.

 

If a single port to a cylinder is clogged it will cause a misfire, this will cause a driveability issue.
True, a misfire will create higher HC due to an incomplete burn, but the through the roof NOx readings are more likely going to take precedence over HC readings.

 

But this is a 98. The intake doesn't have individual EGR ports. It all dumps into the plenum instead, so what would get clogged up is the port from the EGR valve to the plenum. All or none.

 

Clogged EGR as in NO EGR working will never cause a drive ability problem. The EGR port to let in inert gas to help cool the combustion chamber to lower HC.

If the EGR is clogged as in EGR open it will cause major drive ability problems. On little engine (4cyl) it the port is open enough it will cause them to stall at idle.