7

You mention two issues: fast idle hard brakes Both of these point to a vacuum leak. Inspect the brake booster vacuum line; it might have been compromised during the spark plug swap.


5

Yes you can clean it out, but as always, there are some things to be aware of in the process. Use carb cleaner, not gasoline. Do this not only because it will work better, but for safety reasons as well. Brake cleaner would work well, too. When cleaning, you're only cleaning the pocket end (end away from the electrical connection). What you'd be doing is ...


4

The comments are correct. I would start by cleaning the item in the lower right in the diagram below from underneath the intake plenum. Remove it completely by disconnecting the electrical connector, and the unit is usually held in by a few small screws/bolts. Try not to break/cut/destroy the gasket, but be ready to replace the gasket as it must make a ...


4

I had exactly the same problem on a Clio with similar generation. The contacts of the sensor were oxidized. It was not necessary to replace the sensor, plugging it in and out several times solved the issue. Perhaps some contact-cleaning spray could also be helpful.


4

Ford may be trying to match the engine speed to the transmission shaft speed. This would tend to reduce wear on the clutches. When the transmission is shifted back into gear after a down hill run in neutral the transmission has to match the engine to the wheel speed. Depending how different these are clutch wear can be significant. Note that modern fuel ...


3

This may assist in diagnosis May not be an answer for you but you mentioned; The spark plugs are burned at the tip. The definition of burned is important to your diagnosis. If burned means the electrodes are eaten up a beat you could be suffering from a lean condition from a vacuum leak or a sensor not reporting properly to the ECU. IF you have a CEL (...


2

I eventually got this problem fixed. For an unrelated issue, both the throttle position sensor and air flow meter were replaced on the car. When the same idle sticking issue persisted after that, we figured it was probably indeed a mechanical issue with the throttle cable or butterfly throttle valve sticking. Earlier I had used seafoam to clean out the ...


2

I know some of the older GM V-6's had issues with the throttle plate binding in the throttle body. Try to locate the throttle body. It can found by following the large plastic hose attached to the air cleaner box. If you remove the hose you may be able to see some carbon build up. Get a can of throttle cleaner at the local autoparts store and follow the ...


2

It sounds like the carburetors are sticking when hot or you have an air leak between the carbs and the head. I'd recommend using an unlit propane torch, or something like WD40 or spray carburetor cleaner. Spray it around the carburetors and the intake ports. If the idle changes it's an air leak. You could try tapping on the carbs with a screwdriver if it'...


2

Im going to bet that you did not replace the IAC with a new Motorcraft brand. There is a large batch of aftermarket ones that are causing the exact symptoms you describe. You were probably correct in replacing it, but it needs to be a Motorcraft. I had a 2003 Ranger with a high idle complaint. With bi-directional controls, I was able to command the ...


1

Had problem like this before, it turned out to be the coil, once it got hot it separated an internal contact. I fitted a new coil and it was fine. If you can get a known good spare that would be a good test.


1

nothing special to re-learn, just drive normally. may be a little rough at first but will smooth out as the ecu re-learns adaptive values. shifting rpm hold is a new-ish feature on some models. i know the new manual mustangs have it. when you shift the computer will let the rpm drop to the next gear ratio and hold the rpm for a few seconds so when you ...


1

that definitely sounds like an interesting issue you have there. originally i was thinking that the vehicle was equip with shifting rpm hold and it was going on the fritz. but that seems unlikely. it doesn't sound like it would be a vacuum leak because it would idle at 3500 all the time. sounds software related to me. i would try to do a capacitor discharge. ...


1

If your car has a map sensor and developed an air leak that would explain the rising RPMs. In a car with a map sensor the ECU will interpret the additional air flow from a vacuum leak as an increased load and will add fuel causing the car to rev faster.


1

The actual problem was the idle mixture. The screws were not evenly set, and the overall setup was wrong, almost fully closed, while being recommended around -3.5 turns. The problem is now solved, I only need to do a new throttle body sync since the idle screws were uneven when I did the first sync. Thanks for the suggestions.


1

Had the same problem, it was the alcohol gas ... had to drain it from the tank, pull the carbs, and clean then replace and turn down the idle and the engine drag back returned... the alcohol was dissolving the aluminum of the carbs ..looked like snot inside lol


1

You definitely have to do some checking to come up with an accurate solution. The first thing I’d do is check the cables. As noted, it does sound like something is causing the throttle to stay stuck too high. In theory this could also be due to a choke issue. Just warm it up or do whatever you need to to cause the symptom, then (with it in neutral and ...


1

Did you replace the EGRC-BPT valve? Also, you might swap in the old EGR valve (or a different one from another manufacturer) because I was once sold the wrong part number for my EGR valve. Did you check the EGR passageway for clogs? If the EGR valve was functioning improperly, chances are the EGR tubing was carbonized. I had to clean mine out with ...


1

Fuel injected motors have a fuel map in their ECU- quite literally an X-Y grid of ratios of fuel to air that will be fed to the engine. On one axis is throttle position, the other, engine RPM. Those two values determine A/F ratio. In addition to this, there is a "modifier value" to the cells in the A/F ratio table that richens (adds more fuel) for different ...


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