JedGrant

I recently bought an '00 AP1 with roughly 100k miles on the odometer, purchased it from my brother. It has been slightly neglected and has been sitting for roughly 3 years after the engine developed a misfire.

As soon as I got it home I changed the plugs (with NGK iridium), oil, battery, and started it up. Cranked right up but it ran bad. Once pushed past idle, it seems to run fine but I could be wrong. Also has a flashing CEL. I checked the coils and found that if I pulled the 3rd coil pack, the engine ran no different so I changed the coil pack but still no dice ($90 down the drain). Afterwards, I ran the codes and it popped a 1399.

I looked this up and learned that two of the most common causes of the misfire are either needing a valve adjustment or an EGR port becoming clogged. So I adjusted the valves and got them into spec and changed out the valve cover seals, spark plug tube seals, and valve cover bolt grommets. After adjusting the valves and cranking the engine, the CEL went away immediately but the misfire was still there which I then narrowed down to bad gas (the code could have been cleared from the battery dying and causing the ECU to reset, as I had to jump it off).

This evening I pumped out the gas and put fresh 93 in the tank and ran it again and the CEL came back flashing. I haven't checked the codes but I'd be willing to bet it will still be the 1399. I don't believe it is an EGR port because the previous owner said it started misfiring instantly instead of little by little as I would assume exhaust soot would cause.

So I'm at a loss now as to where I need to go next. Taking it to the dealership is not out of the question but I would really prefer fixing it myself. I am pretty decent with cars and don't like anyone else touching my ****.

I'm a broke-*** Marine and can't afford to keep throwing parts at it, anyone have any ideas?

matt da jdm junkie

When in your drive dose it misfire? ie under load/ first start up/ after its warm any and all info will be a great help. seeing as you pulled the codes use the scantool and look at the live data and anything such as fuel trim values short and long term, map voltage, ect temp those sorta values will help the most

Julio salvatier

Having the same problem with all 4 cylinders misfiring it could be many things but try to do all the things that are cheaper first than going and buying coil packs. Try cleaning your injectors and try a cat cleaner. The sensors might be dirty since it sat for a while. Im no mechanic but one of my friends told me to try that first. Doing it this weekend hopefully it will fix my problem. Ill post see if i have any luck!