Hey all, I am new here and I have some questions. I own a pre-owned 1997 F-150 4.6L. it had 64002 miles on it when I bought it in mid 2005. I am now up to about 130,000. Recently it started to ride rough and the engine light came on. What I mean about rough is that when I step on the gas, I can feel a slight shake or hesitation. When I hit the lowest gear when driving (I think 4th gear) the truck sputters if I barely press the gas and there is a definite loss of power. I have a neighbor who has a code reading and it came up as a 401. I thought that my EGR valve went bad so I replaced it and the gasket. This did not fix the problem so I changed out the DPFE Sensor and this still did not fix the problem. I then tore off the Throttle Body and found that the EGR ports were completely clogged. So using a screw and some Air Intake and Throttle Body Cleaner, I proceeded to clean them out. After that, I reinstalled it with new gaskets all around, including the gasket between the two parts of the Throttle Body and the IAC gasket as well. This still did not fix the problem. I am at a loss as to what it might be at this point. Does anyone have any suggestions as to what it might be.

Other thing I have done to it recently are:

Replaced Starter
Replaced the Altenator
Replace and Regapped all the spark plugs
Replaced all plug cables
Oil Change with 0w-30

I don't think that any of these thing are causeing my problem but something is. Please Help.

 

Well, you found the cause of the 401. But it sounds like you also have an engine misfire that hasn't turned on the light yet. Could be bad/cracked plug, spark plug wire, or a coil pack problem. What plug wires were installed? Motorcraft is the best replacements. Does the check engine light flash when it is running rough? If so, it is under a misfire condition. Also could be a fuel pressure problem. Ever change the fuel filter?

 

I am not sure what type of wires without looking. The light flashed when this first started but since I have replace all the forementioned items, it has stopped flashing so far. I do not think it is a cracked plug since i have already checked that. No I have not ever changed the fuel filter. That brings me to a point. When this first start, while going down hill at a certian speed and I barely applied pressure to the gas peddle to such a point before it start to sputter, it seemed to clear up and drive normally. but that only lasted a few days before it was a constant sputter no matter what I did. on another board which I will not metion since I do not know if I can, it was suggested that I have a leak in my vacuum line somewhere. Could this be a possibility?

 

Geezzzzz - Change your fuel filter. I take it you don't believe in maintenance. - Might wanna throw the right oil in their while you at it. Do you even own a manual?

 

#1: 0w30 wow that's just asking for trouble

#2: when is the last time you changed the coils and wires / COPS?

#3: if you have a clogged fuel filter you may have burnt out your fuel pump

#4: pull a plug and see if the truck is running lean

is your truck burning oil? or having blow by into the cylinders?

 

It has not even been a year since I have changed the wires. I changed the plugs a little over 2 months ago. And yes I have read the manual, it recommends 5w-30 but does not require it so I can use different weights. If you don't mind me asking, what is wrong with 0w-30? would they put it on the market if it was design to harm a truck? My truck is not burning oil, my gauge registers the same since I have changed it last which was about 2000 miles ago. I do not know what you mean by "having blow by the cylinders" I am not over mechanically inclined but I can follow directions form my chilton guide. I have never changed the coils as of yet but I have been looking into it. I am waiting for my egine light to come back on to see what code it throws at me since I have unclogged the Throttle body.

 

you may not get a code....



if your TB and elbow was that clogged then mabye your getting oil into teh plugs fouling them out

 

0/30 is better than 5/30 especially if he makes short trips. most of your engine wear happens on cold starts. the 0/30 flows better on cold starts and allows for better lubrication while still maintaining the 30 weight once it warms up.

 

Last Time I checked the plugs were fine.

 

Ok so let me ask this question. I was listening to the engine trying to find a leak but over the egine noise I could not hear a thing. But after I turned the truck off, I went back to the engine and after a few seconds I heard a high pitch wining noise. At first I thought I had found the leak but it did not last long enough the first time for me to track it. So after a few quick starts, I tracked it to the EGR Vacuum Regulator Solenoid. SHould this be making a high pitched wining noise and if not do you think it could be causing all the problems from above? I do get a surge at idleing but it still sputters at idleing as well. Any thoughts?