Vibrates at Idle, Help Please!!!

I've been battling this for over a year. Any suggestions???

This is a 2000 Ford Explorer. 4.0 SOHC with 88K mi. - Originally a Canadian
car, now in Washington state.
It runs great but idles crummy, much more in gear, then in park. It sort of
vibrates, and shudders a little. Just enough to make things rattle. Never
dies though.

ALLDATA indicates idle speed spec. is: Hot Idle 670-750
Scan tool shows avg. idle is 645 in gear.
ALLDATA indicates - low idle, look at fuel, and or ignition?
ALLDATA indicates - vehicle has foul resistant injectors, should not
require cleaning.

ALLDATA indicates - Fuel spec. 30 - 65 lbs.
Tested = Idle in gear 65 - 69 / Idle in park 66 - 68 (never drops to 30)
Leak down test - Fuel system dropped 15lbs. immediatly, then held for
several minutes.
This vehicle uses a mechanically regulated non - return type fuel pump

88k Miles
20k ago changed, plug wires, fuel filter.
Last 6 months changed, spark plugs, IAC, air filter, cleaned the MAF sensor,
two applications of injector cleaner, and cleaned the throttle body.

I think something is causing it to idle too slow. Do you think a slightly
high fuel pressure will do that?
Also fuel pressure spec indicates 30 to 65. This car doesn't drop to 30.
but I don't see how it could, because the system uses a spring loaded bypass
at the pump for regulation.

Thanks again, Rick

Rick, you could have a vacuum leak. That would account for the symptoms you
cite. I'd connect a vacuum gauge and see what that reads. If I remember
correctly, you should read somewhere in the neighborhood of atmospheric
pressure (14-15 psi).

Also, I'd visually check the vacuum hoses to make sure one isn't
disconnected or has an obvious hole. I'd also suspect the IAC, but that's
ruled out since you already changed it.

Another cause could be an EGR valve that has stuck open. To check for this,
place your finger on the underside of the valve with the engine at normal
operating temp (don't burn yourself!). Rev the engine; you should feel the
diaphragm move. If you don't, pull the vac hose and verify that vacuum is
indeed being provided to the valve. If you have vac, and the diaphragm
doesn't move, this is probably your culprit.

Good luck!
Kevin from Wenatchee

"Rick Wolford" > wrote in message
...
> I've been battling this for over a year. Any suggestions???
>
> This is a 2000 Ford Explorer. 4.0 SOHC with 88K mi. - Originally a
> Canadian car, now in Washington state.
> It runs great but idles crummy, much more in gear, then in park. It sort
> of vibrates, and shudders a little. Just enough to make things rattle.
> Never dies though.
>
> ALLDATA indicates idle speed spec. is: Hot Idle 670-750
> Scan tool shows avg. idle is 645 in gear.
> ALLDATA indicates - low idle, look at fuel, and or ignition?
> ALLDATA indicates - vehicle has foul resistant injectors, should not
> require cleaning.
>
> ALLDATA indicates - Fuel spec. 30 - 65 lbs.
> Tested = Idle in gear 65 - 69 / Idle in park 66 - 68 (never drops to 30)
> Leak down test - Fuel system dropped 15lbs. immediatly, then held for
> several minutes.
> This vehicle uses a mechanically regulated non - return type fuel pump
>
> 88k Miles
> 20k ago changed, plug wires, fuel filter.
> Last 6 months changed, spark plugs, IAC, air filter, cleaned the MAF
> sensor, two applications of injector cleaner, and cleaned the throttle
> body.
>
> I think something is causing it to idle too slow. Do you think a slightly
> high fuel pressure will do that?
> Also fuel pressure spec indicates 30 to 65. This car doesn't drop to 30.
> but I don't see how it could, because the system uses a spring loaded
> bypass at the pump for regulation.
>
> Thanks again, Rick
>

> Rick, you could have a vacuum leak. That would account for the symptoms
> you
> cite. I'd connect a vacuum gauge and see what that reads. If I remember
> correctly, you should read somewhere in the neighborhood of atmospheric
> pressure (14-15 psi).

I've scrutinized over and over looking for a vacuum leak. Even disconnecting
hoses to see what happens. Nothing found. As far as PVC, I did the "hold a
piece of paper to the end of hose test", and it checked ok.

> Another cause could be an EGR valve that has stuck open.
I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK test
and it tested ok.

Rick from Vancouver, WA

Replace the fuel pressure regulator.
"Rick Wolford" > wrote in message
...
>
> > Rick, you could have a vacuum leak. That would account for the symptoms
> > you
> > cite. I'd connect a vacuum gauge and see what that reads. If I
remember
> > correctly, you should read somewhere in the neighborhood of atmospheric
> > pressure (14-15 psi).
>
> I've scrutinized over and over looking for a vacuum leak. Even
disconnecting
> hoses to see what happens. Nothing found. As far as PVC, I did the "hold a
> piece of paper to the end of hose test", and it checked ok.
>
> > Another cause could be an EGR valve that has stuck open.
> I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK test
> and it tested ok.
>
> Rick from Vancouver, WA
>
>
>

One other thing came to mind. Carbon tends to build up on the inside of the
EGR valve. If the diaphragm still opens under vacuum, the valve will test
OK. But if there's enough carbon buildup, the valve may not be closing
properly.

Before replacing a fuel regulator, which is probably costly (don't know,
haven't done it myself), I'd pull the EGR valve and see if there is
excessive carbon inside it. You may even be able to see that the valve
isn't closing all the way. You can clean the carbon out with some light
sandpaper, and reinstall it. You'll need a new gasket, which you can
probably buy for cheap at NAPA. Or do what I've done - make one out of a
sheet of gasket material, by using the valve as a template. It's easy
enough to check this before throwing money around shotgun style.

Let us know what you find out!

Kevin

"Rob" > wrote in message
...
> Replace the fuel pressure regulator.
> "Rick Wolford" > wrote in message
> ...
>>
>> > Rick, you could have a vacuum leak. That would account for the
>> > symptoms
>> > you
>> > cite. I'd connect a vacuum gauge and see what that reads. If I
> remember
>> > correctly, you should read somewhere in the neighborhood of atmospheric
>> > pressure (14-15 psi).
>>
>> I've scrutinized over and over looking for a vacuum leak. Even
> disconnecting
>> hoses to see what happens. Nothing found. As far as PVC, I did the "hold
>> a
>> piece of paper to the end of hose test", and it checked ok.
>>
>> > Another cause could be an EGR valve that has stuck open.
>> I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK test
>> and it tested ok.
>>
>> Rick from Vancouver, WA
>>
>>
>>
>
>

66 - 69 PSI is above the 30 - 65 PSi spec.


"Kevin D" > wrote in message
news:cVvVd.27668$uc.12678@trnddc09...
> One other thing came to mind. Carbon tends to build up on the inside of
the
> EGR valve. If the diaphragm still opens under vacuum, the valve will test
> OK. But if there's enough carbon buildup, the valve may not be closing
> properly.
>
> Before replacing a fuel regulator, which is probably costly (don't know,
> haven't done it myself), I'd pull the EGR valve and see if there is
> excessive carbon inside it. You may even be able to see that the valve
> isn't closing all the way. You can clean the carbon out with some light
> sandpaper, and reinstall it. You'll need a new gasket, which you can
> probably buy for cheap at NAPA. Or do what I've done - make one out of a
> sheet of gasket material, by using the valve as a template. It's easy
> enough to check this before throwing money around shotgun style.
>
> Let us know what you find out!
>
> Kevin
>
> "Rob" > wrote in message
> ...
> > Replace the fuel pressure regulator.
> > "Rick Wolford" > wrote in message
> > ...
> >>
> >> > Rick, you could have a vacuum leak. That would account for the
> >> > symptoms
> >> > you
> >> > cite. I'd connect a vacuum gauge and see what that reads. If I
> > remember
> >> > correctly, you should read somewhere in the neighborhood of
atmospheric
> >> > pressure (14-15 psi).
> >>
> >> I've scrutinized over and over looking for a vacuum leak. Even
> > disconnecting
> >> hoses to see what happens. Nothing found. As far as PVC, I did the
"hold
> >> a
> >> piece of paper to the end of hose test", and it checked ok.
> >>
> >> > Another cause could be an EGR valve that has stuck open.
> >> I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK
test
> >> and it tested ok.
> >>
> >> Rick from Vancouver, WA
> >>
> >>
> >>
> >
> >
>
>

Yes, but that is just a range. Does it mean that pressure should be 30 psi
at idle, and 65 above idle? Or does it mean that any pressure between 30
and 65 psi at any time is considered "good"? And how accurate is the
pressure tester? If the pressure was 10 or 15 psi above spec, then yeah -
that's a problem. But 1 to 4 psi could indicate a calibration error, which
could happen with any piece of test equipment.

You may indeed be correct, but the EGR check is quick, easy and most
importantly - cheap. Personally, I'd check all the cheap and easy stuff
first.

"Rob" > wrote in message
...
> 66 - 69 PSI is above the 30 - 65 PSi spec.
>
>
> "Kevin D" > wrote in message
> news:cVvVd.27668$uc.12678@trnddc09...
>> One other thing came to mind. Carbon tends to build up on the inside of
> the
>> EGR valve. If the diaphragm still opens under vacuum, the valve will
>> test
>> OK. But if there's enough carbon buildup, the valve may not be closing
>> properly.
>>
>> Before replacing a fuel regulator, which is probably costly (don't know,
>> haven't done it myself), I'd pull the EGR valve and see if there is
>> excessive carbon inside it. You may even be able to see that the valve
>> isn't closing all the way. You can clean the carbon out with some light
>> sandpaper, and reinstall it. You'll need a new gasket, which you can
>> probably buy for cheap at NAPA. Or do what I've done - make one out of a
>> sheet of gasket material, by using the valve as a template. It's easy
>> enough to check this before throwing money around shotgun style.
>>
>> Let us know what you find out!
>>
>> Kevin
>>
>> "Rob" > wrote in message
>> ...
>> > Replace the fuel pressure regulator.
>> > "Rick Wolford" > wrote in message
>> > ...
>> >>
>> >> > Rick, you could have a vacuum leak. That would account for the
>> >> > symptoms
>> >> > you
>> >> > cite. I'd connect a vacuum gauge and see what that reads. If I
>> > remember
>> >> > correctly, you should read somewhere in the neighborhood of
> atmospheric
>> >> > pressure (14-15 psi).
>> >>
>> >> I've scrutinized over and over looking for a vacuum leak. Even
>> > disconnecting
>> >> hoses to see what happens. Nothing found. As far as PVC, I did the
> "hold
>> >> a
>> >> piece of paper to the end of hose test", and it checked ok.
>> >>
>> >> > Another cause could be an EGR valve that has stuck open.
>> >> I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK
> test
>> >> and it tested ok.
>> >>
>> >> Rick from Vancouver, WA
>> >>
>> >>
>> >>
>> >
>> >
>>
>>
>
>

above 65 or below 30 at any time is bad. This is my last post on the
subject. It's not my truck. Replace what you want.
"Kevin D" > wrote in message
news:kbwVd.27678$uc.3157@trnddc09...
> Yes, but that is just a range. Does it mean that pressure should be 30
psi
> at idle, and 65 above idle? Or does it mean that any pressure between 30
> and 65 psi at any time is considered "good"? And how accurate is the
> pressure tester? If the pressure was 10 or 15 psi above spec, then yeah -
> that's a problem. But 1 to 4 psi could indicate a calibration error,
which
> could happen with any piece of test equipment.
>
> You may indeed be correct, but the EGR check is quick, easy and most
> importantly - cheap. Personally, I'd check all the cheap and easy stuff
> first.
>
> "Rob" > wrote in message
> ...
> > 66 - 69 PSI is above the 30 - 65 PSi spec.
> >
> >
> > "Kevin D" > wrote in message
> > news:cVvVd.27668$uc.12678@trnddc09...
> >> One other thing came to mind. Carbon tends to build up on the inside
of
> > the
> >> EGR valve. If the diaphragm still opens under vacuum, the valve will
> >> test
> >> OK. But if there's enough carbon buildup, the valve may not be closing
> >> properly.
> >>
> >> Before replacing a fuel regulator, which is probably costly (don't
know,
> >> haven't done it myself), I'd pull the EGR valve and see if there is
> >> excessive carbon inside it. You may even be able to see that the valve
> >> isn't closing all the way. You can clean the carbon out with some
light
> >> sandpaper, and reinstall it. You'll need a new gasket, which you can
> >> probably buy for cheap at NAPA. Or do what I've done - make one out of
a
> >> sheet of gasket material, by using the valve as a template. It's easy
> >> enough to check this before throwing money around shotgun style.
> >>
> >> Let us know what you find out!
> >>
> >> Kevin
> >>
> >> "Rob" > wrote in message
> >> ...
> >> > Replace the fuel pressure regulator.
> >> > "Rick Wolford" > wrote in message
> >> > ...
> >> >>
> >> >> > Rick, you could have a vacuum leak. That would account for the
> >> >> > symptoms
> >> >> > you
> >> >> > cite. I'd connect a vacuum gauge and see what that reads. If I
> >> > remember
> >> >> > correctly, you should read somewhere in the neighborhood of
> > atmospheric
> >> >> > pressure (14-15 psi).
> >> >>
> >> >> I've scrutinized over and over looking for a vacuum leak. Even
> >> > disconnecting
> >> >> hoses to see what happens. Nothing found. As far as PVC, I did the
> > "hold
> >> >> a
> >> >> piece of paper to the end of hose test", and it checked ok.
> >> >>
> >> >> > Another cause could be an EGR valve that has stuck open.
> >> >> I have the computer, OBD 2 Browser scan tool. It shows an EGR STUCK
> > test
> >> >> and it tested ok.
> >> >>
> >> >> Rick from Vancouver, WA
> >> >>
> >> >>
> >> >>
> >> >
> >> >
> >>
> >>
> >
> >
>
>

Thanks for the input. I'm going to take a quick look at the EGR, It's easy
enough. But I believe Rob may be right. The pressure should be in spec. I
haven't gone after that yet because the regulator is part of the pump in the
tank. But get this, I notice a definite difference from when tank is full to
tank low. It's lookin more and more like the pump.

Good luck Rick. Glad to help a fellow Washingtonian!

"Rick Wolford" > wrote in message
...
> Thanks for the input. I'm going to take a quick look at the EGR, It's easy
> enough. But I believe Rob may be right. The pressure should be in spec. I
> haven't gone after that yet because the regulator is part of the pump in
> the tank. But get this, I notice a definite difference from when tank is
> full to tank low. It's lookin more and more like the pump.
>