Misfire
Thread Starter
|
New User
Joined: May 2020
Posts: 2
Likes: 0
Misfire
Hey y’all, newbie here. I have a 2001 F550 that I have only driven less than 200 miles in last 4 years. Trying to get it ready to sell. The problem is it keeps loosing cylinders. It will run fine when you crank with no service light on. You start to give it throttle and it seems to loose at least two cylinders and runs horrible. Service engine soon light comes on. Let it keep idling and it will quit misfiring and the see it light will go off. I have read some posts on here and have changed the oil, vacuumed out the HPOP but have not had any luck. Have also read that fuel pumps pretty much work or don’t, not really in between. Any advise? Truck ran great until it was kinda parked 4 years ago.
Got Data?
Joined: Dec 2012
Posts: 4,267
Likes: 1,403
From: Lake Stevens, WA
Hi Robert. You're in the right spot. Let's see what we can do to figure this out.
Right off the top, do you have a way to check the codes? Need to see what the SES light is telling you. A phone with Forscan or Torque Pro on it, and a $20 bluetooth or Wifi OBDII dongle will get it done.
Some basic checks: We'll assume good oil, full on the dipstick. How is the air filter? After sitting, I'm wondering about blockages from critters in the intake area.
Right off the top, do you have a way to check the codes? Need to see what the SES light is telling you. A phone with Forscan or Torque Pro on it, and a $20 bluetooth or Wifi OBDII dongle will get it done.
Some basic checks: We'll assume good oil, full on the dipstick. How is the air filter? After sitting, I'm wondering about blockages from critters in the intake area.
Thread Starter
|
New User
Joined: May 2020
Posts: 2
Likes: 0
Thanks for response. Oil is new/good. I have a cheap scanner that will not bring back any codes. Could this be because service engine light comes on/goes off/comes on/goes off over and over? Checked air filter, was a little dirty but nothing major. Have drained fuel bowl several times to make sure water on bottom was gone. Am I right about it probably not fuel pump? I would think if it was screen in tank or fuel pump, the more throttle you give the more cylinders would cut out due to fuel starvage? Any help is greatly appreciated.
Got Data?
Joined: Dec 2012
Posts: 4,267
Likes: 1,403
From: Lake Stevens, WA
The codes will still be there, light on or off. A typical OBDII scanner will not work on our rigs, but you can still go "cheap". See OBDII Tools link in my signature.
Fuel filter looked ok? replaced in the last 15K miles?
A good way to rule out the fuel pump, broken pickup foot or clogged screens in the tank is to do some testing like @SkySkiJason recommends here:
https://www.ford-trucks.com/forums/1...-test-kit.html
Fuel filter looked ok? replaced in the last 15K miles?
A good way to rule out the fuel pump, broken pickup foot or clogged screens in the tank is to do some testing like @SkySkiJason recommends here:
- Remove the hose from water drain valve on filter.
- Attach 5/16” hose and a clamp to ANY cheap pressure gauge from the local hardware store. Air, water, etc gauge will be FINE for this test.
- Tape the gauge to the outside of windshield and monitor pressure by opening by opening the water drain valve.
https://www.ford-trucks.com/forums/1...-test-kit.html
Got Data?
Joined: Dec 2012
Posts: 4,267
Likes: 1,403
From: Lake Stevens, WA
With the SES light coming on, it could be wiring. Have you checked or replaced the UVC harnesses? They can come loose and exhibit the symptoms you describe. If loose, the 50cent mod would do the trick to secure the OEM latches
https://www.ford-trucks.com/forums/9...ent-mod-2.html.
https://www.ford-trucks.com/forums/9...ent-mod-2.html.
Thread
Thread Starter
Forum
Replies
Last Post
scottinjaxf250
1999 - 2003 7.3L Power Stroke Diesel
4
Jun 4, 2010 08:53 AM
