wont idle in cold weather

[durfey]

wont idle in cold weather

--------------------------------------------------------------------------------

i got a 98 ranger with a 4.0 ohv engine and the check engine light has been on for about a year and a half. it keeps throwing the same code, the fuel system is too lean in banks 1 and 2. I've had my mechanic clean the MAF and both O2 sensors and that didnt work. It has a new MAF sensor and new O2 sensors, new plugs and wires, has been checked for vacuum leaks thoroughly and the vacuum system is plugged off before the vacuum hub solenoid and has been replaced with manual hubs. It runs perfect all summer long but in the canadian winter when it goes below -20 degrees celcius it will idle fine as its warming up but once its at operating temperature it idles like crap and if i leave it idle for too long without feathering the gas at a red light it dies.

Me and my mechanic are both out of ideas other than the ecu? any ideas could be helpful as i may of overlooked something. If i cant find the problem i'll have to sell it this summer when its runnin good.

 

[Rudie Del Rude]

If the lower intake gaskets haven't been changed then there's a good chance they need changed. I was getting the same codes for a while with a loping idlem and changing my intake gaskets fixed the problem. It's hard to determine if its leaking because sometimes it wont pull air from outside the engine. If the leaks bad enough it can suck oil into the combustion chamber too. I sprayed the shit outta my intake with carbon and choke cleaner and it didnt rev up, but changed the gaskets and it fixed it right away.

 

[Fordisthebest30]

dude i would check the cat. My brother in law had the same problem and he had the cat cleaned and it took care of the o2 sensor code, and his truck was an 04, and he lives farther north than you, and it made it run real sh i tty

 

[Original_Ranger84]

Have you thought about changing the Fuel filter? when they switch to winter blend the pump could have stirred up crap on the bottom of the gas station tank and clogged up your fuel filter.

I would also check your fuel pressure regulator. If its running lean it means its not getting enough fuel, a sensor would throw a code if it itself was working properly and sensed something wrong. I would start checking and replacing parts.

 

[durfey]

thanks for the help, i've replaced about every sensor on that engine in the last year or so, I'll try some of the ideas mentioned and if it doesnt work i'll probably have another post.

 

[durfey]

i never fixed this and just pulled the motor out and dropped in an explorer 5.0

 

[sixty9oz]

sounds like a logical fix to me!