Increasing Idle Speed

I've seen many posts where folks complain about their idle speed being too low, causing the car to stall when idling , etc.. In an effort to raise that idle speed, they've gone to great lengths; like making new brackets with adjusting screws to add on to their existing system. But I think I've found a simple way to accomplish the same thing, without all that extra trouble.

My Haynes Manual which covers Escorts and Tracers from 1991 thru 2000, talks about the Throttle Position Sensor. There's a few sentences telling about removal and installation, and then there's these words:

"Rotating the sensor clockwise may cause EXCESSIVE idle speeds." So, isn't this the answer to increasing the idle speed? Just loosen the two screws that hold the Throttle Position Sensor (which is mounted on the Throttle Body), and then just rotate the Throttle Position Sensor a TINY bit clockwise until you've achieved the desired idle speed?

I haven't tried this yet, but I've never seen this fix mentioned on this Forum and I can't help but wonder WHY NOT???

This info. is found in my Haynes Manual on Page 4-18, in the top left corner of the page, paragraph a)

I'd really like to hear any knowledgeable comments on this idea.
Thanks.
yahoo1

There may also be a base idle screw that you can turn up.

There may also be a base idle screw that you can turn up.

You certainly may be right, taillight, but wouldn't it seem likely that someone with the intelligence to design and fabricate a bracket to control their Idle Speed, would know enough to look for an existing Idle Speed adjusting screw?

Looking back thru a large number of threads, I think I can only remember ONE time where someone said something about an existing Idle Screw. I'm NOT inclined to think that there is one, at least on Third Generation Escorts.
If you happen to know for certain that there IS one, then please tell me so.
Thank you!!!
yahoo1

Look at the throttle linkage for a screw hanging down. The head will be covered with a plug that will have to be removed. Drill the cover with a small drill and pry off the cover.

I've seen many posts where folks complain about their idle speed being too low, causing the car to stall when idling , etc.. In an effort to raise that idle speed, they've gone to great lengths; like making new brackets with adjusting screws to add on to their existing system. But I think I've found a simple way to accomplish the same thing, without all that extra trouble.

My Haynes Manual which covers Escorts and Tracers from 1991 thru 2000, talks about the Throttle Position Sensor. There's a few sentences telling about removal and installation, and then there's these words:

"Rotating the sensor clockwise may cause EXCESSIVE idle speeds." So, isn't this the answer to increasing the idle speed? Just loosen the two screws that hold the Throttle Position Sensor (which is mounted on the Throttle Body), and then just rotate the Throttle Position Sensor a TINY bit clockwise until you've achieved the desired idle speed?

I haven't tried this yet, but I've never seen this fix mentioned on this Forum and I can't help but wonder WHY NOT???

This info. is found in my Haynes Manual on Page 4-18, in the top left corner of the page, paragraph a)

I'd really like to hear any knowledgeable comments on this idea.
Thanks.
yahoo1

C'mon people! I came up with what I thought was a fabulous idea, which would get a huge number of responses, and all I get is one person responding.
Is there something wrong with my idea? If so, then what is it?
Thanks!!!!
yahoo1

C'mon people! I came up with what I thought was a fabulous idea, which would get a huge number of responses, and all I get is one person responding.
Is there something wrong with my idea? If so, then what is it?
Thanks!!!!
yahoo1
In theory its a good idea, but you might run into a little problem. You see the PCM is programmed to recognize 3 throttle positions(Closed Throttle CT, Part Throttle PT, and Wide Open Throttle WOT) usually anything above 1.10v is considered Part Throttle, and when it sees that, it alters things like IAC, spark timing, Injection pulse width, etc.
I worked on a car once that the PCM did not recognize this(Part Throttle) as a problem, since its a normal function, it never saw Closed Throttle so it just kept trying to adjust the engine and that would cause a rolling idle. Basically what your doing is telling the PCM "engine's getting more air, throttle's open" but it really isn't. When you adjust it through a screw it actually is getting more air because you're actually opening the valve. You could try it see how it works for you, maybe just ajust it very little at a time to see how far you can push your luck without affecting the normal operation the vehicle.

In theory its a good idea, but you might run into a little problem. You see the PCM is programmed to recognize 3 throttle positions(Closed Throttle CT, Part Throttle PT, and Wide Open Throttle WOT) usually anything above 1.10v is considered Part Throttle, and when it sees that, it alters things like IAC, spark timing, Injection pulse width, etc.
I worked on a car once that the PCM did not recognize this(Part Throttle) as a problem, since its a normal function, it never saw Closed Throttle so it just kept trying to adjust the engine and that would cause a rolling idle. Basically what your doing is telling the PCM "engine's getting more air, throttle's open" but it really isn't. When you adjust it through a screw it actually is getting more air because you're actually opening the valve. You could try it see how it works for you, maybe just ajust it very little at a time to see how far you can push your luck without affecting the normal operation the vehicle.

Thanks for this post, Carlos. I especially appreciate it since it is specifically talking about the Throttle Position Sensor, which is what my original post was asking about.

On cars with carburetors, adjusting the idle speed is usually straightforward.
On most all cars with direct fuel injection, the idle speed is meant to be controlled by the computer - using an Idle Air Control valve (or whatever other names it had). As far as I know the computer learns that you foot is off the gas & the engine should be idling -Only- from the Throttle Position Sensor. So mounting the TPS turned further than it should be or needs to be, is going to cause the computer to think you always have your foot on the gas, and it would initially increase the amount of fuel the injectors were providing. But it would not have any effect on the amount of air the engine was actually getting. So the engine might idle faster, but it would certainly run too rich - and the check engine light would be on all the time. You can also overheat the catylytic converter that way.
I am the default auto repair guy in the extended family, & I have worked on a lot of such cars. I have always found that the idle speed being too low, too high, or uneven, was the result of something else being wrong. Fixing that other problem always resulted in the idle speed being fine again. Sometimes this was just replacing the Idle Air Control valve, or a leaky vacuum line, or cleaning out a sticky Mass Air Flow sensor or replacing spark plugs. Sometimes it meant replacing a clogged fuel injector, doing a valve job, replacing a blown head gasket, or rebuilding an engine.
In Virginia we have emisssions testing in the heavily populated counties. If the Check Engine Light is 'on' you fail the emissions test. On cars made after about 94 or 95, the inspection computer checks the car's computer for its vital info. This will include any codes related to improper conditions and probably the malfunction history too. So even if the check engine light is removed - you still fail the test. And you cant get license plates without passing the emissions test.

On cars with carburetors, adjusting the idle speed is usually straightforward.
On most all cars with direct fuel injection, the idle speed is meant to be controlled by the computer - using an Idle Air Control valve (or whatever other names it had). As far as I know the computer learns that you foot is off the gas & the engine should be idling -Only- from the Throttle Position Sensor. So mounting the TPS turned further than it should be or needs to be, is going to cause the computer to think you always have your foot on the gas, and it would initially increase the amount of fuel the injectors were providing. But it would not have any effect on the amount of air the engine was actually getting. So the engine might idle faster, but it would certainly run too rich - and the check engine light would be on all the time. You can also overheat the catylytic converter that way.
I am the default auto repair guy in the extended family, & I have worked on a lot of such cars. I have always found that the idle speed being too low, too high, or uneven, was the result of something else being wrong. Fixing that other problem always resulted in the idle speed being fine again. Sometimes this was just replacing the Idle Air Control valve, or a leaky vacuum line, or cleaning out a sticky Mass Air Flow sensor or replacing spark plugs. Sometimes it meant replacing a clogged fuel injector, doing a valve job, replacing a blown head gasket, or rebuilding an engine.
In Virginia we have emisssions testing in the heavily populated counties. If the Check Engine Light is 'on' you fail the emissions test. On cars made after about 94 or 95, the inspection computer checks the car's computer for its vital info. This will include any codes related to improper conditions and probably the malfunction history too. So even if the check engine light is removed - you still fail the test. And you cant get license plates without passing the emissions test.

Thank you very much for you great post, denisond3. I guess what it all boils down to, is that I had another great idea that just WON'T FLY!!! Drat!!!
I sure do hate all these automatic controls that they are required to put on cars these days. With all these sensors, valves, computers, etc. that are always breaking down, it amazes me that any cars are able to keep going at all. Not to mention how the cost of repairs HURTS those of us with not enough money to fix these damn, expensive repairs.
Thanks again! yahoo1

Its always good to question things. There really is no such thing as a stupid question or idea, if someone knowledgeable is willing to listen, chances are you'll learn something new or your idea might actually stick.

It was a very good idea... keep thinking those thoughts and you might give us something that causes us to send you beer money as thanks ;)

A well stated problem is a problem half solved.

That's right. I learn something new just about all the time when I am reading the Escort Forum. Everybody does a really good job with helping others out.

Another benefit: Before I would EVER buy a used car, I come to automotiveforums to see what kinds of shortcomings there may be.
I also know what to look for when bargaining for a fair price.