Hello all, I have searched and search and can't find anyone with the same symptoms as myself. I just picked up this car a week ago with no issues. Ran compression test and got 210 across the board. Drove thru the first few tanks of gas with no issues. In the past few days however, every morning when I go to start it up, It begins to idle very rough, and I can hear a little pop every once in a while. If I leave soon after starting, it will bog down until about 2500 rpm. but then will run fine. All these symptoms for the most part go away once I've driven the car for about 15-20 minutes. Or atleast the hesitation issue. Yesterday it bogged down enough to throw a CEL with the codes for a misfire on each cylinder and the 1399 and 0300. I've Cleaned the intake and the IAC valve, changed plugs (old ones looked fine) Took it and had the injectors cleaned at a local place (but they don't do ultrasonic, and the MAP whack. I'm running out of ideas other than just replacing the injectors or sending them off. Is bad gas still a possibility? And will it hurt to drive it like it is for now? No issues of hesitation once warm and no issues cruising down the road. Thanks everyone. Btw, it's a 2000 with 122,000 miles.

 

common issue... people still working on figuring out the culprit.

 

Did you reset the ecu and do the idle relearn after doing all that work? It might be worth while to run some fuel system cleaner thru there as well.

 

Yes I did do ecu reset and idle relearn. I've been running cleaner thru the last couple tanks but it still idles rough and hiccups below 2500.