Maf
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Maf
Hi all. I'm new to this forum and I have a new used 1994 Ford Explorer with a 4.0L engine. I'm having problems with low power. I took the vehicle to a mechanic friend of mine and he agrees it should have more power. The check engine light is on but there are no codes coming up on his Snap-On brand scanner. We are suspecting the MAF sensor because it only outputs 0.7 to 1.75 volts when at idle and gunning the engine. He says the voltage should range from 0.0 to 5.0 volts is this correct. I hate to spend the money on parts swapping but without any codes to go by what else can I do? Any other Ideas?
Other symptoms:
Low temp gage reading(below normal range indications)
Temperature just makes it to normal when driving fast or climbing a hill.
Idles fine/starts fine
Hesitates when accelerated.
When throttled to the floor and climbing a hill it does not shift down and actually pings and looses power until you let off the accelerator, then it shifts down and accelerates slightly but not enough.
Other symptoms:
Low temp gage reading(below normal range indications)
Temperature just makes it to normal when driving fast or climbing a hill.
Idles fine/starts fine
Hesitates when accelerated.
When throttled to the floor and climbing a hill it does not shift down and actually pings and looses power until you let off the accelerator, then it shifts down and accelerates slightly but not enough.
Last edited by 94EXPBAR3; Nov 24, 2003 at 05:50 PM.
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Joined: Dec 2001
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From: UT
On a '94, you can try accessing the trouble codes with just a piece of wire and the codes are output as flashes of the CEL. No fancy scanner necessary. A good repair manual will have directions for the EEC-IV self-tests or check out www.dalidesign.com/hbook/eectest.html
Before replacing the MAF, try cleaning it. Sometimes the filaments get dirty and the MAF loses sensitivity. Get the security torx bits and remove the sensor from the housing, then GENTLY wipe off the filaments with a q-tip and some electric contact cleaner/isporopyl alcohol/other fast drying solvent. A dirty MAF is also a common cause of pinging on hard acceleration.
The temperature problem is probably a stuck thermostat.
Before replacing the MAF, try cleaning it. Sometimes the filaments get dirty and the MAF loses sensitivity. Get the security torx bits and remove the sensor from the housing, then GENTLY wipe off the filaments with a q-tip and some electric contact cleaner/isporopyl alcohol/other fast drying solvent. A dirty MAF is also a common cause of pinging on hard acceleration.
The temperature problem is probably a stuck thermostat.
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Joined: Nov 2003
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From: chino valley az
always clean the maf senser when begining to diagnose low end problems on a maf system. it is easy there are two screws that hold the sensor to the body, the are tamperproof torx. remove them, then gentlylift the sensor from the body, it should be cleaned gently with carb cleaner. when it dry reinstall it. if you have a k&n filter remove it. first the oil will delaminate off of it stick to the "hot wire" on the maf sensor, the dust will enter and stick to it, giving it false readings. this is really common with the ford hot wire maf system.
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Update MAF
Just wanted to update you all. Replacing the MAF sensor took care of the low power when pulling hills(unfortunately my mechanic had it replaced before I mentioned cleaning it first-$150 bucks!). I really wish we would have cleaned it first. Anyway he says he's finished with it and he doesn't understand why he/I still have the CEL when he shows no codes fast or slow. So I take it home and pull the codes using a jumper wire and a test light. They are KOEO 33,21,42,24 and KOER 11,13. Why he couldn't pull them I don't know but there they are just the same. Now I have a list of the codes thanks to mrshorty in one of the above posts and the first code indicates "EGR did not open/ respond during test." How do I verify that the problem is the EGR valve, sensor or faulty information being fed to the PCM? Also I'm thinking about replacing the thermostat because of the low temperature indication shown on the gauge(below normal range) and only 173-175 degrees according to the fancy scanner my mechanic had. What are your thoughts people?
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