hello all...i have a fairly new to me 2000 4.2, it always starts right up in the morning or ive noticed if it sits for a while it will start right up....BUT..if i say just run to the gas station and go to start the truck back up it just cranks and cranks..BUT, if i put the gas pedal to the floor it will slowly and eventually lub lub lub and completly start and then idle really high for a minute or so

i took it to get scanned and got this
P0174-bank 2 combustion too lean
P0125-insufficient coolant temp for closed loop
P0172-system too rich(bank1)

they recommended i look for a vacuum leak, which makes sense becuase when im driving i can hear a kind of "whistle" but it goes away with more rpm and ive sprayed carb cleaner everywhere without a change in rpm so if there is a vac leak i cant find it

what do you guys think?

 

nobody?

 

this forum is a joke, yall are more worried about what light bulbs or if your ecoboost sounds like a v8

 

Well you posted in a general discussion thread instead of a year group where you could have had more views. A lot of people only get on their phones and don't read new posts. Sometimes it takes a bit for people to answer. Getting bent out of shape won't get you an answer faster.

Now, with your codes that you said you had, I'd be looking at the O2 sensors and coolant temperature sensor. Check your coolant level and make sure there is no air in the system. I'm not saying replace the O2 sensors just yet, but you should pull them out and look at them.

 

thanks for the reponse, i would have thought a mod would have pointed me in the right direction by then...wouldnt an o2 throw an o2 code? and the friggin whistling, my god man, it sounds like a jet!

 

Did you spray around the intake or just the connections? 4.2's are known for getting a little warm on the back of the engine. Could have cracked the intake. And your lean/rich conditions are decided by the O2 sensors. I think you have 4, but I could be wrong. Being a 2000, it might be time to change them out.

 

i sprayed everywhere

 

this is from another forum ive been a member of

well i owned it for maybe a week before i noticed the whistle(i would have heard the whistle during that week so im not sure if it just wasnt doing it for that week)...i could never hear it while at idle in or out of the truck but yesterday for the first time i heard it while outside the truck with hood open before i did the carb cleaner vacuum check(btw i did a control test and took a vac line off and i litterally had to spray into the line direstly for any slight rpm change so i dont trust that test anymore, on this truck anyways)it sounded like it was coming from like around the middle of intake to back around the firewall

as for the insufficient Coolant/temp, when its cold my fan is on, ive never seen it slow down or stop, it slows down obviously with rpm but i would think when cold it would really be spinning like it was fully engaged..is that normal?

 

As cheap as the coolant temperature sensor is, I'd replace it to rule it out. Could be the reason you are getting the "Closed Loop" fault. Basically it's triggering the fan and your ECM is saying that your engine isn't hot enough to activate the fan. If you do change the coolant sensor, make sure you get as much of the air out of the system as you can so it doesn't give a false temperature reading.

EDIT** Sensor looks to be about $20.

 

i dont see the temp sensor making me stomp on the throttle to start