Hello all, this is my very first Honda. I have had mercury almost all my life but since turning to Honda, I have realized what I was missing out on. It's a great car. But for the last year, its been misfiring and its getting worse to the point where when I'm slow rolling to a stop, the car shutters. Now not in a way like its going to turn off, just like its missing on only 1 cylinder.

Specs: 98 Accord EX 6 cylinder Vtec.Fully stock. 187,000 miles. Had the car for 3 years.
So far: full tune up, rotor, wires, plugs, PCV valve, , and New airfilter.

CEL flashes on drives father than 5 miles. Idles rough in park. I checked the catalytic (without breaking a screw) and cleaned Egr valve, I have also fully seafoamed the car. CEL stays on even after reset, but only misfire codes once read. I have found some oil on spark plug one and I have identified it is cylinder 1 misfiring by pulling each plug individually. The engine missed hard with plugs 2 thru 6 pulled but no change in misfire frequency when number 1 is pulled. Also smell fumes from exhaust heavy but no smoke except for on startup sometimes.

I have been told at random these are symptoms of valve seals, or piston rings, or head gaskets. I'm not sure which of these it could be. Any suggestions? Did I screw up the firing order when doing the wires a while ago? That's around the time the misfired started.

 

hello.
I would start with checking the order of cylinders to make sure that right wire-right plug.
second- measure the compression in cylinders( i know this might be a pain in in.. with 6cyl) but do it. Harbor freight sell compression testers for cheap.
third-it could be a fuel injector.
I doubt that it is engine oil seals unless the oil was bad whole its life and it was not changed in time. Good luck.
Also sometimes(very rare but...) it could be a defective spark plug. or wire. If you still have the old set of wires try to put them on the car. and replace the spark plugs(cheap price and possible fix)

 

thanks for the info. Just an update, so far still misfiring. Firing order is correct but my initial information was incorrect. Its cylinder 4 that shows no response when I remove the distributor wire from it. All the other plugs are firing and show a response. When I pull the plug with the wire out, i can see the spark plug firing. Can the cylinder be bad? maybe no fuel getting to it? why aren't the others misfiring? this is driving me nuts. Any information would be helpful.

I do plan on compression testing on Monday.

Thanks again for everyone help!!!

 

If you still have a good compression in all cylinders you need to try
1-replace the spark plug cyl 4
2-test if there is a signal to injector 4(indicator bulb will be helpful)
3-replace cyl4 injector with cyl1 injector and see if the problem will occur in cyl 1

 

Hey folks thanks for all the support. Like an *** i ignored the recommended compression test and went strait to the injector. Bought a brand new one, popped the sucker in after lots of fun unbolting and guess what, still the very same misfire!

I will be doing the compression test this week but damn, can 1 only one cylinder lose compression? if so what can cause that? and what should I do if the compression is off in the one cylinder?

just to note, the car has had the tranny rebuilt once before we bought it 2 years ago. The car was in great shape, still is minus the misfire and it has taken us cross country twice, one with a trailer and, and countless times up and down the east and west coasts.

Any and all recommendations are appreciated!

 

There are few items that can cause one cylinder to have low compression:

leaking head gasket
stuck, damaged,... valve
worn piston rings

If you find that you have low compression, then you can do a leakdown test to figure out where/how the pressure is leaking from the cylinder.

 

Have you tried to replace the spark plug? spark plug wire? have you tested the signal to the injector?

 

Yep, changed plugs a second time. I know its not wires rotor or cap. Can it be the coil that sends electricity to the distributor? Like I'm all out of ideas, its still just the one cylinder not firing.

 

Check your EGR valve passages as they may be clogged. get the CEL read to make sure you dont have a code for it. I have a 1998 2.3 VTEC with 2 EGR codes and I am doing the EGR passage cleaning as soon as my tools come in from Harbor Freight. Hopes this helps you fix your issue

 

Well folks you have all been very helpful and I want to thank you all for your replies. Finally did the compression test, and cylinder 4 is reading 80 while all other cylinders read 160. I dunno what the hell it means aside from low compression in the 1 cylinder. I dont know what else to do. The engine performs a little better well i pull the canister hose off of the "cooler silver metal manifold" that sits on the crankcase. I guess it allows more air into the engine. The good ole boys at autozone sugggest i have a headgasket leak or a bad exhaust valve. I dont know how to check for wither and Im starting to fel like my baby is doomed.