cobalt01
New Member
- Joined
- June 28, 2007
- Messages
- 3
- Reaction score
- 0
- City, State
- Tucson, AZ
- Year, Model & Trim Level
- 2000 Sport
I have a 2000 Explorer sport, 4.0 non-overhead cam with 5 speed. I live in Arizona 105+ in the summer. The Explorer has 43k miles. After driving on the interstate at 70+ miles per hour and then exiting to surface streets, within 5 miles it begins surging at idle and taking off is difficult. I am able to hear the fuel pump coming on and off when this occurs. It has not set a check engine light. I have replaced the fuel filter and no change. If I shut it off for just several minutes it will work fine for a short time and the on/off of the fuel pump is not heard. This never occurs with the temperature below 95 degrees. As a precaution, I also never let the vehicle get below 1/4 tank of fuel, as the fuel pump temperature would increase and shorten its life. Any suggestions greatly appreciated.
Additional Information:
While in a failing condition, I attached a fuel pressure gage to the fuel rail. The gage under normal running conditions registers 50 lbs. When failing and the fuel pump coming on and off it would turn off at 50 lbs and turn on at 30 lbs. Letting the vehicle sit in the off position and not running for two minutes will bring the operation back to normal.
Additional Information 07/05/07:
I changed the thermostat, it had the original from Ford. I checked the old thermostat and it was not fully open, even at 200+ degrees. I used a pan and candy thermometer suspending the thermostat off the bottom of pan. This seemed to extend the time of surface streets before noticing any surging. It is definitely heat related.
Thanks,
John
Additional Information:
While in a failing condition, I attached a fuel pressure gage to the fuel rail. The gage under normal running conditions registers 50 lbs. When failing and the fuel pump coming on and off it would turn off at 50 lbs and turn on at 30 lbs. Letting the vehicle sit in the off position and not running for two minutes will bring the operation back to normal.
Additional Information 07/05/07:
I changed the thermostat, it had the original from Ford. I checked the old thermostat and it was not fully open, even at 200+ degrees. I used a pan and candy thermometer suspending the thermostat off the bottom of pan. This seemed to extend the time of surface streets before noticing any surging. It is definitely heat related.
Thanks,
John
