Nedd a little help here, 1997 F150

Cessnadriver · 03-22-2005, 04:48 PM

So here's the scene.
1997 F-150
XLT, 4WD
4.6 L, 167,000 miles, well maintained.
Truck starts fine, no codes.
New plugs, wires, EGR Valve, Fuel filter.
The Problem:
Truck will not accelerate smoothly. Sometimes it is a definite miss, othere it seems like one cylinder is missing, kind of like a "flutter". At constant speeds it is there, but not nearly as bad or always there.
Questions:
Could this be fuel related? Such as bad fuel injector(s).
What are the chances that the Mass Airflow Sensor could be bad/dirty. I've been told that the MAF sensor can be cleaned with isoporpyl alchohol. Would the MAF fail without setting a code?
How about the DPFE sensor?
Fuel pressure regulator/pump?
I've checked the resistance on the TPS, and it seems fine, with no drop outs or spikes in resistance (on an analog meter).
I'm about ready to put another set of plugs in there just to start over.

LCPDuke · 03-22-2005, 05:41 PM

THe least expensive possible problem would be a fuel problem. Possibly injector but also filter. I had a Ford that would run fine but when you acclerate it would sputter a little. New fuel filter fixed it. Simple but effective in my case.

jimmytroanoke · 03-24-2005, 12:16 PM

Did you put anything other than Motorcraft plugs and wires on it. If you did get the OEM parts. I have seen it all over the boards - Especially concerning Bosch plugs and modular V8s. The motorcraft plugs are all that survive. That would be my first guess. Yes the MAF sensor will give you some of the symptoms you are having. Don't know how to clean one though.

peppermrj · 03-24-2005, 03:08 PM

I like chevron with techron. Run a few tanks thru and see if changes things. DPFE sensor are known problems on the newer models, not sure about yours tho. MAF sensor can be dirty and not set a code. There are a lot of instuctions on cleaning them just do a google. Let us know how you make out.

Cessnadriver · 03-25-2005, 09:58 AM

I did a cursory cleaning on the MAF.
See my post under "Suggestions for cleaning MAF" in this forum for details. Looks like the MAF is guilty.

Skyline_Racer · 03-25-2005, 03:22 PM

My friend is having the same prob and he was told to replace the fuel pump, or the fuel filter.

Cait Sith Cat · 03-27-2005, 12:23 AM

fuel filter should be your first try. It's about $10, and a do it yourself in about 5 minutes. Consult your Chilton manual!

tnteverett · 12-06-2005, 07:53 AM

Have had similar problems with my 97 F150.
1. MAF failures.
2. Distributor/Coil failures.

Cessnadriver · 12-06-2005, 10:09 AM

Sorry for not updating this, but I had posted on a number of forums and did not get to them all.
Turns out it was the Autolite plugs all along. I put in Motorcraft plugs and the miss went away. Kinda like getting a new truck. I went to Motorcraft.com and found the current number for the right plug and got them at Autozone.
However, not the antifreeze has all ended up in the crankcase. Either a leakinf freeze plug behind the timing cover, or a blown head gasket.

tnteverett · 12-06-2005, 10:14 AM

Probably the head gasket as that is my current problem at 120,000 miles.

Cessnadriver · 12-06-2005, 12:00 PM

Quote:

Originally Posted by tnteverett

Probably the head gasket as that is my current problem at 120,000 miles.

Is it leaking oil outside the head or dumping coolant into the oil?

I'm trying to think positive, but two knowledeable people have said to put a replacement long block in the truck. ~~$5k with 3 year 75k warranty from Jasper Engines, installed. I can't afford that right now, especially in a '97 truck.

Ouch.

tnteverett · 12-06-2005, 12:05 PM

No oil outside the head ever. I don't think there is coolant in the oil. Hard to tell, last time I checked the oil the dip stick shaft broke off. I don't see anything unusual in the oil fill opening (foam, or other lighter colors).

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