Ignition tune-up (2001 Accord)

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Ignition tune-up (2001 Accord)

Postby sombrio » Mon Mar 14, 2016 9:20 pm

Hey guys:

I don't know if it helps anyone, but I just resolved a misfire issue on my Honda and I thought I'd do a brief write-up. Partly because I feel like bragging, partly because I feel like writing something, and hey, who knows, it might actually help someone too. This was pretty new and scary to me, so maybe my experience will give someone the confidence to try it for themselves.

Here's the background and symptoms. For about a year now my Honda (2.3L inline 4, F23A4) has had a minor misfire or surge in fast idle. I changed the spark plugs (but nothing else) about 6 months ago hoping it would help the problem, but it didn't make any difference. It was running fine overall, but had a slight misfire at idle that could be felt as a minor shake/bump/shimmy/whatever when the engine is warming up. It got slightly worse over time but wasn't anything I was overly concerned about. Fast forward to this past Friday--I started the car and instantly had a severe misfire (like one cylinder was entirely dead or worse), very bad shaking, loss of power, flashing check engine light, etc. The fault codes were "cylinder 1 misfire" and "engine misfire in any cylinder." (I don't remember the exact numbers, but those were the descriptions.)

I drove it home, which felt risky but on further review I think was unlikely to do any real damage. I think I had lost one cylinder completely below 3000 rpm. Above about 3000 rpm it felt fine.

After some research, I decided to change the distributor cap and rotor and spark plug wires. Seemed like a reasonable starting point as they're supposed to be inspected and/or replaced every 30,000 miles anyway. It was pretty easy to get the cap off--the cap is just held down by 3 screws on this car, although the one underneath the cap is hard to reach. The rotor only goes on one way, so there was no need to mark the location, but if you do this on another car you may have to mark the location of the rotor so that you put it on with the right alignment and don't fuck up your ignition timing. Before disconnecting the plug wires, I drew myself a diagram to make sure I had the firing order right. More on this in a moment.

Really everything was pretty easy. But, when I re-connected everything, the engine idled VERY rough--severely shaking, kind of like a washing machine really. I'll skip the hours of cursing, head scratching and diagnostics and skip forward now. After all that, I HAD THE FIRING ORDER WRONG :x :x :x :lol:

So hey, life lesson, double check your work and don't just assume that a shitty diagram you drew in 20 seconds is automatically going to be correct.

I looked it up "just in case," found I had it wrong, put the wires on the right way, and now it runs perfectly. What a relief!

So, all in all, I was able to resolve a really bad misfire and a more or less undriveable condition with about $80-90 and a few hours of work (most of which didn't need to be done at all).

A couple of takeaways that were surprising/interesting to me were:

(1) The engine CAN RUN with the wrong firing order. I don't know what I'd expected, but I thought it would be worse than a very rough idle that, to be honest, just felt like an old 4-cylinder being slightly out of tune. I didn't try driving it, but I felt like it was running "ok but not quite right." It did not feel irregular, just rough. That was a surprise to me.

(2) When I had the firing order wrong, I tried replacing the new spark plug wires with the old one. In contrast to the "running but very rough idle" the car wouldn't start and run at all. So if you're wondering if your spark plug wires are bad, try fucking up the firing order and seeing if it'll run at all. :lol: (Just kidding... don't.)

(3) Spark plug wires are important! I really think this was the entire issue for me. Save yourself a potential headache and change the wires if you're going to change spark plugs.

(4) I understand this is an easy car to work on. But all things considered, troubleshooting this ignition glitch, which was potentially mysterious and gave me a HUGE amount of anxiety about my old reliable car breaking down, just took a couple of days and like $85 in parts. It would have been even easier if I had (a) bought everything at the same time from a single store that had it in stock, instead of trusting Pep Boys to order me the part I needed in timely fashion (bad idea), and (b) looked up the damn firing order in the first place instead of drawing myself a hokey diagram that turned out to be wrong. I feel like I saved myself one or two hundred and all I had to do in the end was turn a few screws, replace a couple of plastic parts, and plug in some new wires.

Easy, and productive! It really is a great feeling to get your car running great again!

Hope this is interesting or informative to someone. And maybe we can swap stories of some DIY maintenance that turned out easier/harder than expected. Cheers :)
sombrio
 
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Re: Ignition tune-up (2001 Accord)

Postby tut » Mon Mar 14, 2016 9:44 pm

+1 for dodgy diagrams causing hours of headaches and delays. Lol
Nowadays I try to disconnect wires as last, and transfer straight on the new one, or disconnecting them in a specific fashion...

But great news on fixing your issue! The feeling would be amazing! Although... Are you feeling anxious about whether you've made a mistake yet? Did you triple check it? And again after every second drive? Worried yet?

You probably shouldn't lol. She'll be right

:cheers: Well done :cheers:
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Re: Ignition tune-up (2001 Accord)

Postby thewalrus » Mon Mar 14, 2016 9:59 pm

That's awesome man! Nothing quite as exhilarating as fixing something for yourself. Especially when you're at a desk job most of the day. Feels almost validating. I've been doing more and more of my own bike maintenance - which is considerably easier than car maintenance. But even then, when I actually get something fixed - or working better - it's a pretty good feeling.

I tinkered a little with the MGB, and fixed a couple of small things. But left most of the stuff to my mechanic.
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