I am going to replace my Mass Air Flow Sensor. I am kind of confused.
I am looking online at Partsamerica and they have a Map-Baro Sensor
which looks to be just the sensor part and a Mass Air Flow Sensor that
contains from the picture a sensor and the air horn assembly.
Am I right? Are the parts I identified so and do I need to replace
the whole thing instead of just replacing the sensor itself.
Of course any change is going to be followed by resetting the
computer. I cleaned my sensor last year and it made a big difference
but now the symptoms are back and I knew I was just buying time when I
cleaned it last time.
I had a hard time starting my car a few weeks ago and turns out my
fuel pump was gone. It is OEM and had well over 100k miles on it. I
got that replaced and the car has run fine. Before the fuel pump went
out I started to notice some performance issues again which were
exactly what happened last year and cleaning the MAF Sensor resolved
the issue as per this newsgroup! The MAP is OEM and now I know I need
to replace it.
I was wondering if a faulty MAF Sensor can cause hard starting where
the engine just turns and does not start and after some amount of time
the vehicle will start. I am sure my MAF needs replacing and I guess
I will find out the answer to some of these questions soon but before
I do so I look forward to hearing what you guys have to say.
If it's hard starting when could I would tend to discount the MAF as
the cause since it's going to be in open loop mode AND enriched due to
the cold start. More likely you are not holding fuel pressure and/or
the new pump is not up to snuff. Did you replace the rubber hose
that's inside the fuel tank? I've been told (no first hand
experience) that there is one in there and that it swells inside,
reducing fuel flow. I've heard others say they crack and leak, also
reducing fuel flow. My 92 has an intermittent hard starting problem.
I'd be interested in hearing how yours runs with the new MAF on it.
My 1992 F150 developed a hard start problem. My mechanic suggested a
simple diagnostic to determine the source of the problem. Rather than
immediately starting the truck, he suggested I switch the ignition to
the run position several times (I usually did it three) before trying to
start the engine (using the "start position"). The truck started
perfectly every time when I followed this procedure. When I told my
mechanic this, he said the problem was definitely in the fuel system. A
further check showed that the system would not hold pressure.
Eventually, after checking the injectors and the regulator, he
determined the problem was the fuel pump. After this was replaced, the
problem was solved.
I changed the MAF Sensor the other day and reset the computer. I have
been driving the vehicle for a couple days now and I have noticed a
tremendous performance increase. The old sensor was the original
and/or may have been replaced once previously a long time ago.
Anyway I am going to fill up again late tomorrow and I will then see
what my gas mileage is then. I know it will be much better as I do
not have to push the gas pedal as far down as I used to.
One note...I need to have the transmissioin fluid changed. I will
have that done with one of those Jiffy Lube machines that flushes all
of the old fluid out.
Congrats. on your sucessful repair.
In ref. to your tranny flush, it is very easy to do yourself. There is a
pretty good write up on WWW.glue.umd.edu/~singletn/exp.html. Also I have a
write up of my experience with it if you are interested.
-Steve ('94 EB 4x4)
OK, here goes.....
I plan to flush the transmission fluid every couple of years so I bought four
gallons of the standard Dextron III/MERCON fluid, to keep the costs down,
instead of the synthetic fluid.
I used two 5gal.buckets calibrated in one gal. increments, one for the new
fluid and one for the old fluid. I have a 1994 E.B.Explorer 4dr 4x4 that has
the auxiliary transmission fluid cooler so the hookup behind the front bumper
was simple. I used clear 3/8" plastic tubing so that we could watch for the
color change in the fluid. My son clamped one tubing line to the metal cooler
inflow line and the other onto the tranny return line. We just let the tubing
run wide open with no clamps or restrictions. I taped the other end of the
tubing to the 5 gal. buckets to keep the spillage to a minimum. Alex got
behind the wheel and started the engine while I watched the first gallon of the
old dark brown fluid flow into the 5 gal. bucket.
UH-OH, I noticed that no fluid was being sucked into the transmission through
the tranny return line. Alex quickly shut off the engine.
Apparently, the transmission in my truck will not suck the fresh fluid in. So,
I got the funnel out and poured the new tranny fluid out of the 5 gal. bucket
back into the gallon containers. We then removed the plastic tubing and hooked
the cooler hose back onto the metal tranny return line. I then poured one
gallon through the funnel into the transmission fill tube to replace the gallon
already pumped out.
We then finished the procedure by letting the engine run at idle pumping old
tranny fluid out into the 5-gal bucket while I poured fresh gallons of fluid
into the filler neck.
Keeping the funnel full of fresh fluid just about kept up with the outflow from
the tranny. I had Alex shut off the engine when the outgoing fluid reached the
four-gallon mark. It had turned nice dark cherry red at about the 3 to 3.5
gal. mark. We removed the tubing, hooked the cooler hose back to the metal
line, wiped up the floor, checked for leaks, checked the fluid level in the
tranny and we were finished.
Time from start to completion was about two hours, including the tedious
refilling of the gallon jugs.
The next time we do this should take about 20 minutes tops, now that we know
exactly what to do.
Four gallons of DextronIII/MERCON at Wal-Mart cost about $17.50 tax and all,
plus a little quality time on a Saturday morning sure beats $80.00 at
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