1987 - 1996 F150 & Larger F-Series Trucks1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks
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Motor runs good. Somehow I lost a great deal of power. From a standstill acceleration is poor. Sounds like the K&N filter should be sucking in the hood. Checked vacuum at idle about 17in. Brought to 2000 rpm held same reading. Does this atomatically tell me the cat is good. Fairly fresh motor (50K), 8K on the 4R70W tranny, 250K on the rest of it. Changed plugs, wires, cap & rotor, PCV, fuel filter, O2 sensor, cleaned the K&N filtercharger. Had a few EEC-IV codes, remedied them, did not reappear. Is it possible for sensors like MLP or EVP to appear in range just enough to effect performance, yet not show up in the trouble codes? Come on Guys, the C*%@y guys at work are having a field day with this. They'd never see 250K on one truck.
I would check fuel pressure. I take the guts out of
schrader valve on the fuel rail (careful it might squirt
fuel) and slide a hose over the fitting with a hose clamp.
Should be High 30's to low 40lbs. A friend had trouble
with his v6 4.0 and it turned out to be the fuel regulator.
He went to the dealer and they said they have been having
problems with 4.0 fuel regulators. I also have taken my
car to the dealer and they run that cleaner stuff through
the injectors and it does help.
When you changed your O2 sensor, did you disconnect the battery? I changed mine in my '84, but did not disconnect. Was still getting bad milage, so I called the dealer. He said you have to disconnect the battery for 10 to 20 minutes on any electric gadget. That allows the computer to reset itself. Go figure.
I feel like somewhat of a dummy. My 1995 F150 4x4 5.0 5spd a/c is the first full blown electronic/computerized vehicle that I've owned. I read in a Haynes manual on changing/correcting ignition timing. I'll be damed if I know what they are taking about. Can someone in plain english tell me how they check timing. What do I disconnect or block. I don't have my manual in front of me so I'm forgetting things. What is Thick Film? Thanks in advance.
Doug, the computer advances the timing, bringing the 10 up to about 17 degrees. So to manually adjust timing, you have to unhook the computer. Over by the cruise control box, on the fendor you'll find a little hookup, that should have a little "connector" inside it. This is the spout connector, with the engine off, unhook it, and then you can check your timing.
Pastmaster's 1993 XLT 5.0 E40d 3.55LS Normal Cab/Long bed Loaded from the factory with aid of...MSd 6a ign/s.p. wires, blaster coil, Hypertech Chip, K&N filtercharger, Cat-back dual exhuast w/o mufflers, 3.5", echo tips, Accel distributor cap, Dark Mocha over light mocha. 5% Dark tint, Alpine Cd player/remote, Pioneer speakers.
No such thing as a Ford dummy!
To check the timing, first warm-up the engine. Shut it off and connect the timing light as you normally would (#1 cylinder is front passenger side). Disconnect the SPOUT connector, this is located on the driver's side, between the firewall and engine compartment fuse box. The SPOUT connector will be a single wire with a white plastic removable shorting bar. This bar resembles a long fuse, remove this shorting bar. You now have removed any computer advance. Time the truck to 10 degrees before top dead center. Reinstall SPOUT connector, check with the timing light that the advance signal is working (rev up a little, advance should change).
PS. make sure you are in neutral and wheels are chocked, otherwise it could ruin your holiday. Good luck, Bill
This truck is still getting 10mpg. Since replaced coil, no change. Feels like the truck needs a ton a fuel/air to get going. What do you know about Manual Lever Position Sensor on a 4R70W Transmission. Also EVP sensor tested range is 3700-670 ohms, seems too low on the high side and too high on the low side. What do you think? Any info would greatly help.
my f-150 5.0 4x4 mod was acting funny when i bought it. when i started from a stop i had sluggish power, poor gas milage and hesitation when i romped on the gas pedal. i replaced spark plugs,wires, fuel filter, vacuum leaks (found none), aair filter, checked copm codes all good, cchecked egr good, replaced the tps. you wont believe where i found the problem. it was the map sensor. i replaced it and erased the computor and she has ben running like a gem since. i had the same dilema when i checked my timing. it took me a day to find the spout connector for the timing. all it is is a suitcase jumper. its on the driverside on our truck. good luck
You said when you scanned the EEC-IV, you had no trouble codes. Wounldn't the MAP sensor show up as a code if it was bad? Or maybe it's just not getting the full range. I checked The EGR & EVP. Note EVP range should be greater than 100 to less than 5000 ohms, I have 600 - 3700 ohms. Could this be a functioning sensor but just not functioning in the full range as it should? Could the MAP sensor have a similiar problem? Will test MAP today an see whats up. BILL
I have a 1999 Ford F150 with 130,000+ miles on it. Never did anything to it except change the oil. Last few months, it starting getting sluggish, and made a funny noise (like it was chugging) when I started it. Today, the battery died. I replaced the battery, and I could not believe it. It drove like a brand new truck. Better acceleration, smoother, and great gas milage. Never knew the battery could do that, but I think it was because when it went under load, the voltage dropped from 12 to 14 all the way down to about 9. This must have run the computers nuts. If nothing else works for you, try swapping out the battery. Worked for me!
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