Surging/Missfire Issue 99 V8 Explorer

[VW/FordGuy]

Hello all,

I got a 99 V8 explorer and for the past few months I have had a issue where the vehicle has a surge to it when in o/d with a slight load on the gas pedal. Also If I have to full throttle it during the entire rpm range it has a slight missfire. Now I am a mechanic so you can be technical if you have a explanation. I am not highly intelligent on the ford coil pack v8's though so bare with me. Now I will tell you what I have done so far. I replaced the plugs,fuel filter,wires about 4 months ago for a tune up. I replaced the cam sensor about a month ago. I just put a fuel pump in the truck literally 4 hours ago. (I had a new one from a customer that never showed so I used it). The one coil pack I noticed where the plug goes in is cracked and the plug wobbles even when its plugged in. But I have no issues when it rains. I also do not have a check engine light. So any help on this would be greatly appreciated. It seems from the surging I have been having and the missfire it seemed to wear out the outer transfer case bearing but I do not wanna tear that down and replace that until I fix this issue. I am also getting very poor gas mileage.

Thanks in advance

 

[JEastonjr]

check the fuel pump pressure at the rail. should be about 60 lbs and hold when you shut off the ign.

 

[VW/FordGuy]

I checked the fuel pressure a while back when I had a starting issue. What happened was when I would let the truck sit for 15-30 mins and go back out to start it up it would take a little bit to start back up. I check the pressure during that issue and during cranking is was only at 15psi and once it would catch it self it would jump back up and then start. My starting issue seems to be fixed as of today from the pump. But I will definetly check the pressure again tommorw and report back. I think I am leaning more towards a ignition problem from the way the sputter feels during hard acceleration but I could always be wrong.

Thanks again

 

[Turdle]

Ignition caused misfires will not always trigger a po30X code on the v8. However a failing fuel injector will.

If I ever suspect a misfire in the ignition, and see a crack on an ignition component, I cannot assume the crack is "no big deal"

Since the misfire is at low RPMs and under load, I suspect this cracked coil pack.

Also, recently, there has been a noticeable rise in failing , brand new spark plugs. You can identify a fouling plug with a timing light on each ignition wire-check to see if each wire triggers the light to flash.

 

[VW/FordGuy]

Well lets throw the coil packs out on this criteria, Just put some on and that is not the issue either. When I was doing that I realised I actually didnt replace the wires. You think that could cause what I am feeling. I let it warm up and took it for a ride from a dead stop to around 65mph (Full throttle) it feels like you are going up a rollercoaster right before it drops down the hill, it has a jerking back and forth feeling when it accelerates (best way to describe it). I got a set of noid lights I will have to check the injectors out. I put a used cam shaft sychronizer in a while back, but if I remember correctly it didnt hesitate at that time. I am just tryin to think if maybe I went a tooth off. This is just very frustrating =). Thank you for all the help so far and I will 100% be putting my contribution in to become a full member after all this great help so far.

Thank you so far

 

[swetrid]

Wires are always a problem on 5.0L

 

[VW/FordGuy]

Ok for the price I planned on changing them anyways but I am gonna pick some up here shortly and report back.

A mechanic friend of mine that I work with (Ford Guy) is insisting on its the torque converter. It does not feel like a converter at all. Especially because it has been doing the exact thing for months now. A converter gradually gets worse. This has not.

 

[windsors03cobra]

Miles on the rig please ?

 

[VW/FordGuy]

218,000 thousand on the truck, I put a jasper long block in it 111,000 miles ago. but..... Heads were redone about 10,000 miles ago by me. All the gaskets from the heads up were replaced. I use the truck hard so I try and maintain it and catch everything before the problem starts. No real engine mods except full exhaust and k&n drop in, and a 4 in lift with larger tires but nothing else besides that if it helps.