blakshukvw
Well-Known Member
- Joined
- July 14, 2009
- Messages
- 530
- Reaction score
- 116
- City, State
- K.C. mo
- Year, Model & Trim Level
- 2001 Explorer XLT 5.0
So as stated in the title, my 01 5.0 is having some pretty regular hard misfire. It runs good at throttle tip in and low speed cruising and even at high speed with little load. When I approach a hill and increase throttle to maintain speed it begins to misfire/surge heavily while it waits to shift out of OD. Even after it shifts out of OD it still misfires/surges heavily while trying to accelerate.
I've been running some tests at work. Of course in all this no codes. Disconnected the vacuum to the egr and it ran the same. Started running some tests on fuel pressure and found that when the pump primes upon cycling key it only gets about 20- 25 lbs of pressure. If I cycle the key a few times it comes up to 65 or so. It crank a little longer than usual when the key hasn't been cycled to build pressure to 65 but when running it maintains 65 lbs give or take a couple. I have yet to test drive with the gauge on because it will require removing the hood but I'm interested to see what the pressure is when it's surging like it does.
So I'm gonna run a scope on the ignition tomorrow to see if there's an issue with any of the wires or coils. So what should I make of the fuel pump priming low pressure and is that related to the poor performance?
I've been running some tests at work. Of course in all this no codes. Disconnected the vacuum to the egr and it ran the same. Started running some tests on fuel pressure and found that when the pump primes upon cycling key it only gets about 20- 25 lbs of pressure. If I cycle the key a few times it comes up to 65 or so. It crank a little longer than usual when the key hasn't been cycled to build pressure to 65 but when running it maintains 65 lbs give or take a couple. I have yet to test drive with the gauge on because it will require removing the hood but I'm interested to see what the pressure is when it's surging like it does.
So I'm gonna run a scope on the ignition tomorrow to see if there's an issue with any of the wires or coils. So what should I make of the fuel pump priming low pressure and is that related to the poor performance?