P1390 + low idle + misfire?

kneeon · Post by **kneeon** » Mon Jul 11, 2011 12:27 pm

ok so my car when its warmed up idles @600 and my cel is on cause of the p1390,now i did everything to try and fix the idle except for messing with the idle screw and no change. so now listen to this i went to get my a/c fixed and they telling me in addition that i have a misfire and i asked why and he said cause it idles low and it wants to stall. can anyone tell me whats really wrong cause im getting so many different awnsers

g_force58 · Post by **g_force58** » Mon Jul 11, 2011 2:47 pm

P1390 is manufactuer ingnition fault or misfire. Try cleaning the throttle body and the idle air control. usually this will correct the low idle. How long since you changed the plugs and wires? It is possible for the low idle to cause a misfire, but my bet is you have a combined problem. What type of plugs are you running? unless boosted you might want to run the factory Champion plugs as our engines seem to like them the best. I put platinums in mine and got only 15,000 miles or so out of them, others here have had similar results. Possible too the coil pack is going bad. try the small stuff first and work your way thru. Lots of help in the how to section. Good Luck.

kneeon · Post by **kneeon** » Mon Jul 11, 2011 2:56 pm

I put in new factory plugs and wires within the last 500miles.how do i clean the iacv and i cleaned the throttle body, also the p1390 is a problem with the belt skipped 1 or more teeth and the sensors are off if i read it right. So if i fix my belt problem and clean the iac will it be ok?

Post by **occasional demons** » Mon Jul 11, 2011 9:37 pm

What year, and how many miles are on yor car?
If the belt has skipped a tooth or more on it's own, you may have serious issues with the belt, or the tensioner.

Misfire codes are p0300, p0301, p0302, p0303, p0304. Not sure how they came up with a misfire diagnosis, other than sound.

If it is popping out the intake, it is because the valves are opening late. Get the timing belt, components, and water pump checked out ASAP.

kneeon · Post by **kneeon** » Mon Jul 11, 2011 9:52 pm

Its a 01 with 77k and yea thats what im gonna have to get asap its kinda unexpected but hey stuff happens. So im gonna do that and see what happens and hope it changes the way my car is

Post by **occasional demons** » Mon Jul 11, 2011 10:08 pm

Yep, the last thing you need is a few bent valves. You hydraulic belt tensioner may have seized, and is not holding the right tension. While mine had not let the belt slip, it was seized when I replaced everything at 112,000. Age may be the bigger factor here, than mileage.

Related for more info: viewtopic.php?t=57401

steamer1227 · Post by **steamer1227** » Mon Jul 11, 2011 10:44 pm

^ agree

Def make sure timing is ok.

kneeon · Post by **kneeon** » Mon Aug 01, 2011 5:13 pm

Thanks for the help guys but ive decided to let my neon die when the time comes only cause i picked up a nice swap

2GN.ORG

P1390 + low idle + misfire?

P1390 + low idle + misfire?

P1390+low idle+misfire