Engine Surging
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Member
Joined: Jan 2003
Posts: 11
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From: kansas
Engine Surging
I've got a frustrating issue with my engine. It surges when the rpm is below 2500 and the throttle is pressed. Sometimes barely moving the throttle is enough and then sometimes moving the throttle about 1/4 of the way does it. Once the rpm gets to 2500, the surging immediately stops no matter what position the throttle is at. The check engine light is on and the code the computer shows relates to the EGR system. I have replaced every part of that except the EVR (the sensor the engine/EGR vacuum lines mate to) because no one has that part in stock. Not sure if the surging and the check engine light are related. Anyone have an idea what the root cause of the surging is?
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Joined: Jun 2002
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From: Under the flightpath of old ORD 22R
A few questions.
What year and what size engine ?
Also what is the code number.
I am guessing by the list you gave above that is could be a P0401, but I am unsure.
If it is a 4.6L engine, they are more prone to having the EGR elbow clogged, and this might cause a P0401.
Or it could be the DPFE sensor, or a dirty MAFS per wht JMC has posted, or a cracked VAC line ( you noted replacing parts, but nothing either way of you replaced VAC lines ).
Lots of things to suggest, but I would rather wait until you posted the code, before I have you running around like a chicken with your head cut off replacing more stuff needlessly.
What year and what size engine ?
Also what is the code number.
I am guessing by the list you gave above that is could be a P0401, but I am unsure.
If it is a 4.6L engine, they are more prone to having the EGR elbow clogged, and this might cause a P0401.
Or it could be the DPFE sensor, or a dirty MAFS per wht JMC has posted, or a cracked VAC line ( you noted replacing parts, but nothing either way of you replaced VAC lines ).
Lots of things to suggest, but I would rather wait until you posted the code, before I have you running around like a chicken with your head cut off replacing more stuff needlessly.
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Joined: Jan 2003
Posts: 11
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From: kansas
Engine size is 302V8 EFI, 193,000 miles, 5-speed.
code was either 23 or 32.
I'll check the vacuum lines. I'll laugh(and beat my head against a brick wall!) if it is a loose vacuum line. I've been dealing with this for a long time. Thanks for the help.
code was either 23 or 32.
I'll check the vacuum lines. I'll laugh(and beat my head against a brick wall!) if it is a loose vacuum line. I've been dealing with this for a long time. Thanks for the help.
Technical Article Contributor
Joined: Jun 2002
Posts: 10,511
Likes: 10
From: Under the flightpath of old ORD 22R
sbcict,
I'm going to have to step aside, as I don't recall squat about the pre 96 codes & problem diags.
I don't know if this has been listed in the Pre-97 forum or not, maybe that is another place to check.
https://www.f150online.com/forums/fo...?s=&forumid=51
Another place is if you can get your hands on a service manual for your year truck, it should list the steps to take.
Also I think JMC has a pretty good memory for this stuff, if he is along in a bit to help you out.
All the stuff I was talikng about were specific to the 96 and newer years, so while the vac line part may apply, I would not know for sure on the next steps.
Good luck with the vac lines, and hope you get some additional feedback from other members on this.
I'm going to have to step aside, as I don't recall squat about the pre 96 codes & problem diags.
I don't know if this has been listed in the Pre-97 forum or not, maybe that is another place to check.
https://www.f150online.com/forums/fo...?s=&forumid=51
Another place is if you can get your hands on a service manual for your year truck, it should list the steps to take.
Also I think JMC has a pretty good memory for this stuff, if he is along in a bit to help you out.
All the stuff I was talikng about were specific to the 96 and newer years, so while the vac line part may apply, I would not know for sure on the next steps.
Good luck with the vac lines, and hope you get some additional feedback from other members on this.