Kenpo_S2000

I put on a new valve cover gasket, new spark plug seals and new spark plugs. That cured my misfire codes. I only have one code that comes up but no check engine light. It reads P1399. Can someone please tell me what that is.
Thanks

SenderGreen

I believe that is the DTC for a random misfire. I have only seen this in conjunction with other DTC's indicating the misfiring cylinder eg; P1301, P1302, P1303, or P1304 for cylinders 1-4. This is all from memory, but someone will correct me shortly if I'm mistaken. Good Luck

Billman250

P1399 is a temp random misfire code, sorry to break it to ya.

Kenpo_S2000

So what exactly is a temp random misfire and how do I go about fixing that? I have set the VAFC II to intialization so that is back to stock.

the_DZA

I had this same problem. Had random misfires and all that jazz. Did the map whack and reset the ecu. Been fine ever since.

Billman250

It's a temporary misfire code. It will turn into a hard code (like P0300) if it's persistent. I'd be very suspect of the VAFC unit. Everybody I know that has one has lots of troubles.

There are many causes for a multiple misfire across the board. These would be common to all cyls misfiring:

-Lean condition, from low fuel psi, engine managment, or vac leaks
-weak spark
-poor fuel quality
-rich/flooding
-poor compression (unlikely)

The spark plugs will tell the story, if you know how to read them.

SenderGreen

Mine needed a valve adjustment when I had the problem.

Kenpo_S2000

DZA what is the map whack?

Bill when you talk about running lean, the air/fuel gauge seems to dip into the lean every once in a while and seems to bog the car down. Not as much once I changed out the plugs and put new seals in, but it still seems to dip into the lean too much.

Bill thanks for the input. I am a newbie at this so I will have someone read your comments and go from there. I do not have a rough idle and the car seems to run smooth and strong. I will have to do a compression check and see what that reads to make sure. Will the VAFC II effect the engine even when it is in intialization mode? I bought the car with the VAFC installed and I don't care for it seeing as how I don't have a dyno around. Will I run into any problems disconnecting everything. I just want to sell the thing or trade it off.

Kenpo_S2000

Sender how did you find out you needed a valve adjustment. Is this from a compression leak test?

SenderGreen

Kenpo, My car was throwing CEL/MIL when it was very new, I took it to the dealer (before I had a scanner as well), they diagnosed the problem over several trips. They started with the coil paks and sparks. I do believe they did compression and leak down test by the time it was all over. Good Luck