Hi, I'm a newbie, I just signed up. But I have been reading your forums for a while. I have a 2001 E-150 customized van that I use to pull a 28 foot travel trailer. I just noticed on my trip last week when I was accelerating to get up onto the interstate that when I pushed the pedal down halfway or more, there was less power, and felt like it was missing. When I would let up on the pedal, back to a third of the way down, it would run fine, and I had more power.

It starts good, and idles good, when I'm not pulling the trailer, I never push the pedal down far, and I have never noticed it before. Has anyone ever run across this missing under heavy load, and what do you think it is?

 

ramtec; Hello & welcome to FTE you should begin by replacing the fuel filter if you have not done so in a long time, this has been known to cause various engine issues.
LIVE LONG AND PROSPER...........TURBO TED

 

Thanks Turbo Ted, that will be the first thing I replace. Does anyone know where it is at the van?

 

I've read a few other topics around here and it looks like I might need to check the COP. (Coil over plugs) Did Ford think they had a better IDEA by putting these coils over the plugs. It looks like it is a trouble spot now for all Ford owners of gasoline engines. My son's 96 mustang has a regular coil with spark plug wires, and he never has any problem with ignition. My old van had the 351 engine in it with never any spark problem. I think Ford screwed up when they went to these COPs. Does anyone know why they went to this?????

 

How about a few more responses from experienced people?????

 

How is this for experience??????
turbo TED
Senior User Join Date: Jun 2003
Location: WEST TEXAS
Posts: 305

Hey guys check out TSB 98-23-10 which is about MAF contamination - basically that one says you need to be sure the MAF sensor wires are not contaminated. Also, this info relates to also , so parts of it may or may not be applicable. There is also far more troubleshooting info in the tech manuals themselves - these are just the TSBs.FUEL SYSTEM MONITOR
Diagnostic Trouble Code Description Possible Causes
P0148 - Fuel Delivery Error At least one bank lean at wide open throttle. Fuel System:· Severely restricted fuel filter · Severely restricted fuel supply line P0171 - System Too Lean (Bank 1) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit. Fuel System: · Contaminated fuel injectors · Low fuel pressure or running out of fuel (fuel pump, filter, fuel
supply line restrictions) · Vapor recovery system (VMV)
Induction System: · MAF contamination
· Air leaks between the MAF and throttle body · Vacuum leaks·PCV system concern · Improperly seated engine oil dipstick EGRSystem: · Leaking gasket · Stuck EGR valve · Leaking diaphragm or EVR Base Engine:
· Exhaust leaks before or near the HO2S · Secondary air concern
Powertrain Control System: · PCM concern
P0174 - System Too Lean (Bank 2) Same as DTC P0171, but Bank 2. See Possible Causes for DTC P0171
F4.) Tips Related to the Fuel System Monitor
HO2S sensors are not likely to be the cause of adaptive DTCs P0171, P0172, P0174, P0175: Most warranty-returned HO2S sensors (replaced for these DTCs) are found to function normally. Additional related DTCs will normally be present if there is a concern with the HO2S sensors. Do not replace an HO2S sensor unless verified through pinpoint diagnostic tests found in the PC/ED Service Manual. DTCs P0171, P0172, P0174, and P0175 are not related to downstream HO2S sensors: When diagnosing a vehicle with a MIL On and DTC(s) P0171, P0172, P0174, and/or P0175 in continuous memory, do not replace the downstream HO2S sensors. These DTCs have no connection to the downstream HO2S sensor function nor its diagnosis for faults. Always verify the vehicle concern, then perform the pinpoint diagnostics from the appropriate PC/ED Service Manual.
Diagnosing lean conditions and lean DTCs P0171, P0174: Freeze Frame Data can often help to identify the type of lean condition, even if the fault is intermittent, by indicating how the vehicle was being driven when the fault occurred. Diagnosis of lean conditions and lean adaptive DTCs can be difficult, especially if the concern is intermittent. Verifying the concern is extremely important. There are different types of lean conditions. The ability to identify the type of lean condition causing the concern can be crucial to a correct diagnosis. When DTCs P0171 and P0174 are both present, there is a strong likelihood of another concern being present: Vacuum leaks/unmetered air: In this type of condition, the engine may actually run lean of stoichiometry (14.7:1 air/fuel ratio) if the PCM is not able to compensate enough to correct for the condition. This condition is typically caused by air entering the engine through an abnormal source (opening), or due to a MAF malfunction. In this situation, the volume of air entering the engine is actually greater than what the MAF is indicating to the PCM. Vacuum leaks will normally be most apparent when high manifold vacuum is present, during idle or light throttle. If Freeze Frame Data indicates that the fault occurred at idle, a check for vacuum leaks/unmetered air when the engine is cold might be the best starting point. Examples: Loose, leaking or disconnected vacuum lines, intake manifold gaskets or O-rings, throttle body gaskets, brake booster, air inlet tube, stuck/frozen/aftermarket PCV valve, unseated engine oil dipstick, MAF reading lower than normal, etc. Insufficient fueling: In this type of condition, the engine may actually run lean of stoichiometry (14.7:1 air/fuel ratio) if the PCM is not able to compensate enough to correct for the condition. This condition is typically caused by a fuel delivery system concern that restricts or limits the amount of fuel being delivered to the engine. This condition will normally be most apparent when the engine is under a heavy load, when a higher volume of fuel is required. If Freeze Frame Data indicates that the fault occurred under a heavy load, a check of the fuel delivery system (checking fuel pressure with engine under a load) might be the best starting point. Examples: Low fuel pressure (fuel pump, fuel filter, fuel leaks, restricted fuel supply lines), fuel injector concerns, etc.
Exhaust system leaks: In this type of condition, the engine may actually be running near stoichiometry (14.7:1 air/fuel ratio), but the exhaust gas mixture will be lean. This condition is caused by oxygen-rich air entering the exhaust system through an external source. This condition will cause the exhaust gas mixture to be lean, even though the actual combustion in the engine may not be. Examples: Exhaust system leaks upstream or near HO2S, malfunctioning Secondary Air Injection system.
MAF concerns: If a MAF concern is suspected, see TSB 98-23-10 .
Checking fuel pressure: Check fuel pressure with engine under a load when diagnosing a lean concern. A partially plugged fuel filter can be difficult to detect and can be easily overlooked if fuel pressure is only checked at idle. The same is true for other types of fuel supply concerns (e.g., bent or kinked lines, degraded fuel pump). At idle, an engine requires only a small volume of fuel. Due to the fact that there is a small volume of fuel needed at idle, a restriction in the fuel supply line in many cases will not cause the fuel pressure to be low. When the vehicle is under a load, the engine requires much more fuel than at idle. Under a load, a restriction in the fuel supply line will prevent the high rate of fuel flow that is needed to maintain the correct fuel pressure.
's really hard to post everything in the TSBs - I'd recommend an account at alldatadiy or picking up one of the DVDs (the CD manuals do NOT have the TSBs).
LIVE LONG AND PROSPER...................TURBO TED

 

Wow Turbo Ted, that is a whole lot of information and experience. Thanks for responding. I did buy the filter, and a Haynes Repair manual for the van and I see where the filter is located. Then I went and bought the tool to change out the filter. I work 12 hour shifts, so on my next set of days off, that is the first thing I will do is to change the filter. I will report back here to let you know how it turns out.

 

Thanks Turbo Ted,
It was the fuel filter. I glad it wasn't anything more complicated than that. As soon as I changed it, all of the engine's power came back. I do have a question for you, I am assuming that the fuel pump is in the tank, is there a filter on the fuel pump also?

 

There should be a sock type screen on it. Not easily accessable though.