4.9L GUNS AT STARTUP
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4.9L GUNS AT STARTUP
I just purchased a 93 F-150 Ext cab with a 4.9L inline 6. It has a few quirks which I am trying to iron out.
First, when you start the truck it initially revs up real high (probably 2500RPM or so) for about 5 seconds and then comes back to normal idle. I suspect a leaaking injector?
Second, aand this may or may not be related to the first problem, but the truck lacks power. It will move along just fine but has to downshift to climb even a minor grade. I also own a Ranger with a 2.9 and a Marquis with a 4.6 and both of these have much more power than this larger six. If I gun it up it goes, but will not climb without hammering the accelerator and forcing a downshift and higher RPM. No power in the lower RPM range. I have replaced the plugs, cap, rotor,and set the timing, but to little or no improvement. Any hints on what to check next?
To provide more details, the truck has 78,000 miles and is equipped with an E4OD automatic. There has been no check engine light activity so I would suppose no trouble codes are stored to help me out.
Any help would be appreciated.
First, when you start the truck it initially revs up real high (probably 2500RPM or so) for about 5 seconds and then comes back to normal idle. I suspect a leaaking injector?
Second, aand this may or may not be related to the first problem, but the truck lacks power. It will move along just fine but has to downshift to climb even a minor grade. I also own a Ranger with a 2.9 and a Marquis with a 4.6 and both of these have much more power than this larger six. If I gun it up it goes, but will not climb without hammering the accelerator and forcing a downshift and higher RPM. No power in the lower RPM range. I have replaced the plugs, cap, rotor,and set the timing, but to little or no improvement. Any hints on what to check next?
To provide more details, the truck has 78,000 miles and is equipped with an E4OD automatic. There has been no check engine light activity so I would suppose no trouble codes are stored to help me out.
Any help would be appreciated.
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Joined: Jun 1999
Posts: 1,083
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4.9L GUNS AT STARTUP
It's normal for your truck to rev up at idle, that's to get the oil pressure up right away. If it clatters (valve clatter) right at first, you might want to change oil filters to a brand that doesn't let the oil drain back entirely.
As for your other problem, I would:
1.) have the tranny flushed and filled with new juice
2.) go to this web site and learn how to fetch codes yourself through the check engine light: http://www.dalidesign.com/hbook/eectest.html
3.) consider replacing your O2 sensor...not that expensive for fresh start since you just bought this truck
4.) did you pull the spout plug when setting the timing? If not, your base timing may be off and that could account for some loss of power.
5.) recheck your plugs and wires...it's entirely possible to get a dinker even in new stuff, it's happened to me.
Let us know how it goes. You've got a good truck with the best engine ford ever made IMHO. Go slow and get it running to suit you...then run it right for as long as it lasts.
As for your other problem, I would:
1.) have the tranny flushed and filled with new juice
2.) go to this web site and learn how to fetch codes yourself through the check engine light: http://www.dalidesign.com/hbook/eectest.html
3.) consider replacing your O2 sensor...not that expensive for fresh start since you just bought this truck
4.) did you pull the spout plug when setting the timing? If not, your base timing may be off and that could account for some loss of power.
5.) recheck your plugs and wires...it's entirely possible to get a dinker even in new stuff, it's happened to me.
Let us know how it goes. You've got a good truck with the best engine ford ever made IMHO. Go slow and get it running to suit you...then run it right for as long as it lasts.
