ranger has a miss when under a load
#1
ranger has a miss when under a load
Hi, new to this site. my ranger is a 99 with a 3.0 ffv 4x2 that has a miss when it is under a load, but soon as i hit about 20-25 mph it comes out of it but it will do it when going up a fairly steep hill and has to shift down. the fuel pressure is good holds at about 55lbs. i have not found a vacuum leak. the catalytic converter is off right now it was causing the truck to be even more sluggish (couldn't hold even 30 mph up our hills). if anyone has ever had an issue like this and figured it out your help would be much appreciated.
#2
#3
RF Veteran
iTrader: (1)
Coil can cause misfire on 1 cylinder but because each of the 3 coils in the pack spark 2 spark plugs at the same time it is more likely to cause a 2 cylinder misfire.
Same with computer, you would have a double misfire.
65psi is the correct fuel pressure for 1999 and up Ranger
1998 and older used return line, fuel pressure on those was 35-40psi
But I doubt thats your problem since you have a specific miss, not random.
It could just be a bad spark plug, have you pulled them out and looked at them, checked the gap?
A spark plug can fire fine and then quit under load, not a common problem but not unheard of either.
As engine load goes up the spark plug requires more voltage to "jump the gap", if spark plug wire or the spark plug itself is dropping voltage then it quits firing until load is reduced.
That is why someone suggested changing the coil, it starts there, although coil packs are very reliable, I would have started at the other end and inspected plugs and wires.
Same with computer, you would have a double misfire.
65psi is the correct fuel pressure for 1999 and up Ranger
1998 and older used return line, fuel pressure on those was 35-40psi
But I doubt thats your problem since you have a specific miss, not random.
It could just be a bad spark plug, have you pulled them out and looked at them, checked the gap?
A spark plug can fire fine and then quit under load, not a common problem but not unheard of either.
As engine load goes up the spark plug requires more voltage to "jump the gap", if spark plug wire or the spark plug itself is dropping voltage then it quits firing until load is reduced.
That is why someone suggested changing the coil, it starts there, although coil packs are very reliable, I would have started at the other end and inspected plugs and wires.
#5
This is a late update but got it fixed ended up being the throttle position sensor the guy i took it too thought that it could have been the E85 fuel sensor and cleaned the connections up leading to that sensor also.
My bit of advise if you have this problem find someone that knows their fords
My bit of advise if you have this problem find someone that knows their fords
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