high idle speed

[priceless]

Hello I have a ford galaxy 2.3 146 horsepower. for some time now there are problems with idle speed rise to 4000, 5000 rpm and I can not understand what the problem is. Аll the vacuums are clogged, no air leaks, but I don't know how to handle. Can you help me, please!
Another problem is what are the good quality spark plug cables for this model? I have used NGK cabels, but the last time i was disapointed! Thanks!

[brianh]

Shorted out cruise control wiring or a faulty switch is a possible cause, or something causing the throttle to open further than it should. If it is the cruise then it should drop out if you push either the clutch or brake pedals down (provided the switches on them work).

You could also rule out the cruise control by removing the plug from the vacuum pump, the pump is in the front wing on the lefthand side of the car (this is the case for UK spec RHD, if you have a LHD it may be somewhere else).

Spark plug leads i've not had issues with on the 2.3, I think the current ones i've got are probabbly generic no-name ones (prospark I think). I had more problems with the 2.0 which has different leads to the 2.3 and different coil packs. What options do you have where you are? Bosch, motorcraft or similar should be fine, NGK should also be ok though.

[SirDavidAlhambra]

Could try putting a bottle of redex through the tank too, that stuff cures all sorts of ailments lol

[priceless]

Shorted out cruise control wiring or a faulty switch is a possible cause, or something causing the throttle to open further than it should. If it is the cruise then it should drop out if you push either the clutch or brake pedals down (provided the switches on them work).

You could also rule out the cruise control by removing the plug from the vacuum pump, the pump is in the front wing on the lefthand side of the car (this is the case for UK spec RHD, if you have a LHD it may be somewhere else).

Spark plug leads i've not had issues with on the 2.3, I think the current ones i've got are probabbly generic no-name ones (prospark I think). I had more problems with the 2.0 which has different leads to the 2.3 and different coil packs. What options do you have where you are? Bosch, motorcraft or similar should be fine, NGK should also be ok though.



Thanks Brianh! That was very helpful!

[priceless]

I'v been thinking about this !

[brianh]

The other thing I've had fail (this was on the 2.0 but the throttle is the same on both) is the boot where the throttle cable goes onto the body. It could sometimes come off the stub on the bracket, and jam itself at an angle. I fixed mine with the aid of a cable tie to hold it in the right place. That only tended to bring the revs upto around 2000 rpm at worst a bit randomly. But damage to the throttle cable could explain it.

Really something has got to be causing the throttle to open too much, if it was an injection related issue or sparks related you would expect to run poorly or cut out, not rev excessively. Just a matter of finding out what. There may be a fuse for the cruise (if you have it even, as it is an option) that you could pull to isolate it. But either that or disconnecting either the pump as detailed above, or the servo should give you an answer.

[priceless]

I don't have cruise control, but a service center told me that it could be from the servo, because sometimes when I press the brakes I hear air suction. I did a test once - while the engine was running at high speed, I pulled the servo hose and plugged it with my finger, I also plugged the servo itself, but the speed was still high. I felt the hose, but it wasn't cracked. from this I understand that the servo has no connection or am I wrong?

[johnnyroper]

If it still runs high with servo hose disconnected and plugged you can discount the servo itself.
Canââ,¬â,,¢t help thinking itââ,¬â,,¢s drawing air in somewhere to cause the fault,can you run it with pipe from throttle body off to see position of the throttle flap? Is the 2.3 cable driven or fly by wire throttle?

If itââ,¬â,,¢s revving at 5k and throttle flap is closed then you are definitely looking at an air leak.

[SirDavidAlhambra]

I had a similar problem on a Saab once, it turned out that the potentiometer inside the throttle body was worn out and was giving bad feedback to the shipââ,¬â,,¢s computer. Is it possible that the throttle body is faulty?

[brianh]

the 2.3 has a cable operated throttle, not an electronic one so a faulty pot whilst it might cause issues, won't be causing revving like that described.

The servo I meant would be the servo that does the cruise control (there is a servo that automatically pulls the acclerator down to increase engine speed) But you don't have that so we can discount that possible cause. But the comments about the brake servo also apply. Worth being aware that the hose that supplies the servo with vacuum is prone to splitting, usually underneath where you can't see it. Its worth taking it off to properly inspect it, as even when split it the brakes still appear to work as they should, but can be allowing excess air in that way. If it is split, best way I've found to fix that is with a section of silicone vacuum hose, you can reuse the original end fittings like that, and if you get the right size hose it doesn't even need any clips.

You should be able to remove the pipe from the airbox to the throttle body and see whats going on with the throttle flap then. Theres also an idle control valve on the flap though I doubt you'd get enough air going through that to allow excessive revving as described even if it was fully open.

Do you have access to any diagnostics? Torque on a phone and a bluetooth adaptor might give some idea whats going on with sensor readings and fuel trims.

[Chrispb]

May also be worth checking PCV valve and piping although not known that to cause such high RPM

https://www.fordmpv.com/smf2/ford-galaxy-common-faults-and-problems/engine-cutting-out-when-cold/