chickenstar

CEL for P0300, P0301, P0303, P0304 consistently, no performance loss, changed spark plugs TWICE (paid a "JDM Specialist" to replace my spark plugs because "Bosch are so trash I'm surprised it's running" even though I changed them 2 weeks ago) $200 down the drain and guy almost fights me when he tries to charge me another $300 to try a valve adjustment after he was wrong and I call him a thief. Professional f@#king thief is what he was.

Anyways.

Took out coil packs 1 by 1, they all make my engine stumble equally so I believe they aren't my culprit.. no ticks or knocks even on a very cold start so I can't see how my valves need adjustment but I'm no "JDM Specialist" so that's why I'm here. Should I clean my fuel rail? Guy I bought it from said it's a fresh rebuild and my pistons looks brand new, so I do believe him, but who really knows until I dissect it myself..

Rode around town with my buddy, absolutely no codes pop up (not even pending) until around the end of the day and the car sits and I start driving for about 10 minutes every time..

Any ideas before I blow more money that I would like to spend on an AEM Series 2 to get rid of these misfires?

Thanks.

Slowcrash_101

$300 for a valve adjustment?!?!

Just because the car passes the power balance test doesn't mean the coils are all good. For all you know it could just be a wonky battery, although it never hurts to do a valve adjustment, I wonder if this person has experience doing them given what he's charging. Guy should not charge you for more than an hour and a half of labor, that's how long it takes to adjust every single valve.

chubbys2k

Search through the misfire threads on here. Theres plenty of info and how to diagnose those misfires. I hope the person you bought the car from knew what they were doing when rebuilding this engine. These motors are not the easiest when it comes to the stock sleeves.

Chance S2K

Have you checked the injectors? Also, what's your location (state)?

chickenstar

I'm in Florida, haven't checked injectors just yet, but have run a few bottles of Lucas Oil and about to seafoam tomorrow.. Dude charged me an hour of labor to change spark plugs, he was nothing but a thief. He used a cheap electro-meter to check my coilpacks, didn't even tell him the volts just that electricity was flowing through. I guess I'll just change my coilpacks and report back


btw how can I check injectors myself?

Slowcrash_101

Where in Fl? I'm in the Miami area.

Gotpepsi

Don't waste your money on Lucas oil/seafoam or coil packs just yet. See if you can swap coils with another s2000 and see if the misfire goes away. Your exhaust is probably popping right? Swap the coils and see if the popping goes away. You can clean the injectors by shooting carb cleaner through them, but you need to rig up a system to do so. There are some Youtube videos showing you how to do this. I think they use a tube, air compressor, battery, and wires to activate the injectors. Or (which may be a better idea), is to take your injectors out and get them professionally cleaned and flow tested.

P.s. didn't see that the engine was rebuilt. You may want to rule out the big stuff by doing a compression/leak down test to ensure that everything is right. This will probably give you peace of mind as well. Everything else is pretty minor (spark plugs, valve adjustment, coils, injectors) and easy to rule out compared to a faulty engine.

chickenstar

I'm located in East Orlando

chickenstar

Well I ran injector cleaner 2 days ago and nothing but a pending code for 1399, no CEL. Crossing my fingers my injectors are just dirty. I did order some coilpacks though, because I know nobody with an S2000 or K Series engine to test on.

Chuck S

https://www.s2ki.com/...559-code-p1399/

The maintenance manual had trouble shooting guides for the misfires. I doubt your JDM expert has this manual.

Since 1399 is a "pending" code one suggestion is run the car until it isolates what cylinder has the problem.

-- Chuck