I have a 1991 Ford Explorer V6 4.0L. When I start it up when it has
been run for about 10 or more miles and has cooled for a few minutes,
it has trouble starting up again. It will start up, get to about 1,000
rpm and die. It usually runs at about 1,000 rpm. It will do that a few
times, then it starts getting better, or if I wait for a minute it will
get better. When it does, it runs around 600-700 rpm, like it is
starving.
I replaced the O2 sensor, and it seemed to get better for a week or so,
but it started happening again gradually. I replaced the fuel filter,
but it didn't help. Does anyone know why this would happen?
fweddybear - 18 Jan 2006 04:06 GMT
>I have a 1991 Ford Explorer V6 4.0L. When I start it up when it has
> been run for about 10 or more miles and has cooled for a few minutes,
[quoted text clipped - 6 lines]
> but it started happening again gradually. I replaced the fuel filter,
> but it didn't help. Does anyone know why this would happen?
Did you do a diagnostic test on it that said you needed the O2 sensor?
If so, you may have more than one.....in mine, the check engine light came
on.... and brought it to a repair man who told me he needed to replace the
sensor.... it lasted about 2 weeks when the light came on again... brought
it back and he replaced the second one and that fixed the problem....
nothing since..
Fwed
Cam - 18 Jan 2006 04:09 GMT
I didn't check engine codes, I just thought it was a fuel mixture
problem or something, and started replacing stuff from the cheapest up,
and it needs a new O2 sensor about every 80k miles or so anyway. I was
only aware of one O2 sensor in the 1991 explorer, I could be wrong
though.
service@thebetterbatterygroup.com - 18 Jan 2006 04:25 GMT
Typically when you have trouble starting up after a vehicle is warm it
is a good indication your starter is going bad.
But if it were your starter it wouldn't be shutting off after its
running.
How many miles do you have on the vehicle?
Cam - 18 Jan 2006 04:34 GMT
186,000. What else would I look for if the starter were going bad?
gobroncos - 18 Jan 2006 09:43 GMT
Its not your starter. Try the Engine Coolant Temperature sensor. The
voltage drop across this sensor corresponds to the temp of the engine
coolant. Take a voltage reading of this sensor with key-on-engine-off
(engine cold). Start the vehicle, then monitor this same voltage as the
car warms up. It should change, as the temp changes...Jim
Cam - 19 Jan 2006 04:30 GMT
I don't have a voltage meter, so I just replaced the sensor. It didn't
fix the problem, but the old sensor needed to be replaced anyway. After
I re-started the car when it was warm after replacing the sensor, it
wanted to die and acted like it normally would while dying but barely
hung on, so it got a little better. When I pressed on the gas, it
didn't go, and kicked a little, then went and kept kicking, like it is
starving for fuel still. Any other ideas?
gobroncos - 19 Jan 2006 16:18 GMT
This is a tough one! I'm assuming that there are no problems when it is
started when completely cold. 2. That it runs fine after its first
start in the morning? 3. That the probelm only presents itself once it
is shut off, and a restart is attempted prior to it cooling completely?
Cam - 20 Jan 2006 03:15 GMT
Yes. It starts just fine when it is cold. Immedietely after I restart
the car when it is shut off, it goes fine; it is just after 15 or more
minutes, until it is very near cool, that it won't start right.
Cam - 21 Jan 2006 06:56 GMT
I bought a code reader for my car for $40, it was cheaper than having
the codes read in a shop. the KOEO and KOER tests turned out just fine,
said there was nothing wrong. I am stumped.
Cam - 21 Jan 2006 06:57 GMT
I bought an engine code reader for $40. It was cheaper than taking it
to a shop to have the codes read. It read good for the KOEO and KOER
tests. I guess I will have to wait until it breaks, because I'm out of
ideas.