MOOSEcannoN

I've been having a problem with a slight misfire. Usually misfires are electrical right? It used to be quite bad, like only running on 3 cylinders, I replaced my plugs and distributor cap to no avail, there was what looked like rust on the distributor rotor (i think thats what it's called?) so I gave it a very light sanding just to get the rusty stuff off, was this a good idea or a big no no ? all of the above didn't work.
Then I realised there was oil around spark plug number 1 and also in the end of the sparkplug wire, I cleaned it out, I had some old spark plug leads lying around so I replaced them with those and the misfire seemed to have disappeared. I took her for a drive and she misfires less now but still doesn't have the right amount of power. When accelerating is a bit jerky, it seems fine at idle, maybe a tiny misfire every 2 or 3 seconds.
I'm thinking it might be the old sparkplug wires I'm using? or perhaps I shouldn't have sanded the contact on the distributor rotor (I only sanded it very lightly). I don't know, need some help/opinions!

UI8281

hey MOOSE sorry I didn't reply to your old thread, I have been super busy. It sounds like the o-ring around your spark plug well is leaking oil onto the plug. you can replace this by pulling the rocker cover off and replacing the rocker cover gasket and o-rings. Do you get a mild electric shock if you hold the spark plug wires or near the coil? If so they could be "leaking" electricity which will lead to a power loss.

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N14 chassis + N15 Autech sr20de = Hybrid

MOOSEcannoN

hey no worries man. I replaced the HT leads and it fixed the misfire xD
But for some reason it doesnt have as much power as it used to, pulling out into traffic and putting my foot down feels different, there's also this hill with a passing lane that I drive a lot and can usually make it up the hill doing 110km/h in 5th and can even slightly gain speed, now when driving up the same hill in 5th doing 110 I lose speed ever so slightly, end up doing about 100 by the time I hit the top. Is there anything that I can check further? or is it possible that driving with a misfire had done some damage to my engine? I'd love to get the timing checked or the car tuned but poor student here will have to save his penny's

I'd say it occasionally misfires at about 1-3000rpm, after that it's smooth but still not as powerful as an SR20 should be, kinda feels like a 1500 :\ but it still sounds like all cylinders are firing to me

richardwbb

I would replace plugs, rotor, cap anyway, especially with mileage on those. You sand them? wtf?

For the cables, I can't tell from here but they sound old. Just replace, doesn't need to be expensive.

If you have a coil cable, replace that one too. Coil itself could be culprit, I dunno why it goes slow uphill.

It all starts with a strong spark.

MOOSEcannoN

I replaced the cap, leads + coil cable and plugs, lightly sanded some of the corrosion off the distributor rotor, not too much as I didn't want it to lose metal. So you're saying I should replace the coil and the rotor?

UI8281

Haha is that the passing lane up the hill north of whangarei or the one to the south? Either way I used to be able to accelerate up both of them in my old 1275cc MG in top gear (4th). Have you pulled out and inspected the plugs after all of the misfiring?

MOOSEcannoN

haha true, it's the hill with the passing south of whangarei. I haven't thoroughly inspected the bung leads, why's that?

UI8281

Sorry I didn't see that you have replaced the plugs. is it still leaking oil into the spak plug wells?

MOOSEcannoN

umm nah no oil has re-appeared, it must have been slowly getting in there. I will however have another look just in-case

richardwbb

If you not have an original rotor, that will help.

For the coil, it is an expensive part. I tried testing my own, wasn't very clear to me. Then I swapped my coil for another used one from a car with same mileage and no signs of that coil being replaced before either.

It then drove like the engine just had a full tuneup.

So you might want to test your coil first. I saw them here and there for $60 and I would just get it for that price, just like one wants to replace cables. However, they are double that price overhere and then it is really a lot of money.

For the valve cover, with high mileage it wouldn't hurt to replace it and just make sure you get the 5 rings beforehand too. Maybe also give your valvecover a nice look.

Then you can take a look at the state of your cam lobes, they should be shiny and show no signs of wear, always good to know and you should find only brown or goldish oil. Black oil/ sludge is not good and gunk is really bad. Maybe time to use engine flush additive and flush the engine once or twice with cheaper then cheap oil (and drive a few hundred miles with that) Before you start this, remove carterpan, clean it out too.

Old black oil can become thin which is bad and also not great for compression.

I also still have a tiny misfire once in a while with warmed engine. I yet have to mess with some extra injectors I bought, but I tried everything else already.

Take a look at you spark plugs they should show brown tip, black carbon ring (dry) and clean electrode.

Besides the coil which shouldn't be so bad but you never know, test it before replacing, it might solve your issue. All other things probably only will help, but everybody should check this after 100-150k miles.

You could use liquid gasket on those 5 rings and the valve cover gasket might be reusable too, but if it is old, just replace. use very little liquid gasket on the half moon thingies, even with a new one.

HTH