Hey guys,

Interesting issue on my '90 sedan. 5speed w/ B18A1.

A few weeks ago I washed my engine and I broke the distributor cap gasket. I guess it didn't like the degreaser or maybe I was a little too enthusiastic with the hose? Anyways, the gasket failed and I realized it right away when I felt that familiar stumble under acceleration. If you've ever gotten water in your cap you know what I'm talking about. A misfire on one cylinder.

Upon inspection I could even see the broken gasket hanging out. I was kinda lazy and drove it like that for a couple weeks... getting really bad MPG's and no power at all. But I was busy, so I just kept driving it (stupid). It rains a lot here so I figured there was just always some moisture in the cap. I wasn't too concerned, even though the problem seemed to get a little worse over time (at this point the misfire is there at idle as well as under load up to about 3-3500rpm).

I finally replaced the gasket this week. While I was in there I found some ugly corrosion on the points, so I replaced the cap and rotor as well.

When that didn't fix the problem, I took a look at my plugs. The one in cylinder 1 was pretty fouled up so at least I know for sure which cylinder is misfiring. I replaced the plug and the problem still persists. I checked the plug for spark and it is sparking.

At this point I don't think it's an ignition issue... but I'm not sure what else it could be. I want to blame something electrical because the symptoms started when I washed the engine. Is it possible that my original ignition issue has turned into a mechanical issue due to neglect? Burnt exhaust valve maybe?? Are there any more simple possibilities that I'm overlooking?

 

Bump for not having any luck searching...

 

so is it a dead miss?

 

I'm not sure what a dead miss is? It doesn't always miss, just under 3500. There's a noticeable surge when it comes alive again. Like VTEC kicked in... 1st cylinder kicked in, yo!

 

you say it misses at idle as well, by dead miss i mean does it feel like it is consistently running on 3 cylinders?
and have you checked for codes?

 

Usually when it starts from cold it will run smooth at high idle for a bit. But the first time you drive, the problem starts and then it will miss consistently. I'm pretty much always on 3 cylinders below 3500 rpm.

Needless to say my fuel economy has been pretty crappy... I'm driving my other car now and just trying to get this one running again so I have a chance of selling it.

I have not checked for codes, didn't even think of it. Well that's embarrassing. Isn't there usually a CEL involved when you get error codes? Or is my ignorance showing?

 

the cel will not necessarily remain illuminated. a code may still be stored. i'd check that first and foremost. could save you a lot of time.

if it is basically a dead miss, with the engine running (like crap), pull the #1 plug wire. see if there is any change. if not, try swapping the wire to another cylinder. see if the problem follows the wire

 

sounds like a dead cylinder to me, do a compression test or cylinder leakage test

 

Thanks for the ideas guys, will check for codes and the wire and report back, maybe compression test after that if nothing becomes apparent.

 

how are the wires? is there any white marks on the wire of the cylinder that is missfiring? from what you said above im begining to think the wires might be goin back and could be shorting out through the block

 

if you have enough lenght in the wire switch it with another cylinder wire and see if the missfiring cylinder changes

 

The wire looks okay, I know it could still be the problem though. Unfortunately none of the other three are long enough to reach. Neither are the ones from my Prelude. I do have some friends with Hondas but I think they're all SOHC.

Still need to get my codes checked.

 

if there's no change when you pull the #1 wire, you can use the #1 wire on another cylinder. it should still run the same as it did with the #1 wire pulled, since you're still only running it on 3 cylinders. if not, wire is bad

 

Tried running wire #1 in cyl #2 without a wire to cyl 1. Results: I can't tell if it is running on the three cylinders, or only two and sporadically a third. At idle it feels just like it does with wire #1 plugged into cyl #1 as normal (rough, obviously 3 cylinders though). On acceleration it feels even weaker and rougher, ALMOST like it's on two cylinders, but... can a 4cyl engine even run on just two? I guess so since #3 and #4 would be on opposite cycles?? The test seems inconclusive to me. Maybe someone who knows what they're doing could tell.

I thought of a friend I might be able to borrow a wire from. I should be able to get to his place in the next couple of days. And to a parts store on Saturday as well- a code would be nice because at least I'd know.

More symptoms to note in the meantime: when I first start the car from cold, it seems to runs smooth until it warms up a little and the idle slows down. Then it goes into crappy mode. Just now when I did the test, I got in the car and bombed around the neighborhood with normal power for the first few minutes.

 

car may be overfueling. you should really be checking the codes before performing any other diagnostics
but if you want to swap the wires, you first have to confirm that there is no change in idle when you pull the #1 wire (remember, you said #1, not 4). if there is no change in idle, you should be able to swap the #1 wire with another cylinder and if the wire is good, there should be no change in idle

 

The problem is too sporadic to tell a difference just by pulling the wire. The stupid thing runs fine for the first couple minutes, when it's cold.

I guess that pretty much rules out a plug wire issue?

I'll get codes this weekend before doing anything else...

 

doesn't necessarily rule it out. with heat comes resistance, and vise versa. if a wire is on its way out, the added resistance when hot could be enough to cause the misfire. when you checked for spark initially, was it with the #1 plug wire? at operating temp? when you pulled the #1 plug wire, it was at operating temp?
at this point, you really need to check for codes