truck runs rough with a cold motor

StrokinHarley · Aug 20, 2012

So truck has always ran a little rough on a cold motor, just changed my oil and its horrible now. So I took it to a local guy I trust he ran his computer says that injector #2 and #5 dont work COLD. Also says that injector #8 dropped in and out once while he test drove it. My question is how does an injector not work when its cold but is fine when its warm?

Atsah · Aug 20, 2012

The spool valve sticks until warm with an injector with a sticky spool valve..

cfdeng7 · Aug 20, 2012

The spool valves that actuate the injector tend to stick when the oil is cold. Lots of guys have good luck with revx oil additive. But eventually plan to do injectors. What oil do you use?

StrokinHarley · Aug 20, 2012

I use the Motorcraft Oil for Powerstrokes, I know alot of guys have there opinions on oil. I figure Motorcraft cant be to bad. Thought about using the RevX but its just a band aid, think I'll replace those three for now.

ooo and thanks for the replies guys I thought it had to do with the oil being cold just didnt know for sure.

Atsah · Aug 20, 2012

Are you also useing a Motorcraft filter? and what are your fuel filter change intervals? Do you have the updated FPR kit installed? Your mileage?

cfdeng7 · Aug 20, 2012

Atsah said:
Are you also useing a Motorcraft filter? and what are your fuel filter change intervals? Do you have the updated FPR kit installed? Your mileage?

Beat me to it mark.

Atsah · Aug 20, 2012

cfdeng7 said:
Beat me to it mark.

LOL You got this anyway's.. I have to take the dog for his run..LOL

HOOV3R · Aug 20, 2012

Might wanna try running some thinner oil (10w-30) or synthetic.

StrokinHarley · Aug 20, 2012

Yes also running motorcraft fuel filters and oil filters changing the oil ever 4 to 5k and fuel filters ever other so 8 to 10k. mileage on the truck is 100,9xx bought it with 86k

Atsah · Aug 20, 2012

StrokinHarley said:
Yes also running motorcraft fuel filters and oil filters changing the oil ever 4 to 5k and fuel filters ever other so 8 to 10k. mileage on the truck is 100,9xx bought it with 86k

Sounds good.. If you don't have it, the updated fuel pressure regulator kit is about $72.00 at the Ford dealer, it raises your fuel pressure about 10PSI and your injectors will like the added pressure.. I don't know where you live but if it gets cold there you may want to use Motorcraft HD 10W30 or a 5W40 oil for the winter.. You can run a synthetic 5W40 year round no matter where you live..