Reprogramming Engine Computer

[yahoo1]

My 2002 escort often shakes something awful at idle. (I think it's worst when it's about half warmed up).

Anyway, I'm wondering if it's possible to reprogram the engine computer, to make it idle a little faster during this warm-up period. Anyone happen to know if it's possible to change the programming of engine computers?
Thanks a lot!!
yahoo1

[AzTumbleweed]

It probably shouldn't be doing this so my advice is to get it fixed. You might be wasting that precious gasoline

[mightymoose_22]

It sounds like a vacuum leak. Once the car warms up it requires less air... but is still sucking extra air in from somewhere that it shouldn't.
Check the condition of all the hoses attached to the intake manifold very carefully. Listening with a stethoscope or through a length of rubber hose might help to isolate a hissing sound from the leak. I usually use some very soapy water and spray it around on the hoses and where the intake manifold meets the head. Check one area at a time... when the hissing is the loudest, or when the idle improves (if spraying the soapy water), you have found the leak.

You describe a very typical symptom of a vacuum leak. Don't go about trying to mess with adjusting the idle. That will cause more problems.

[yahoo1]

Thanks for your comments, guys! You wouldn't believe what a problem this "shaking" has been for me since the day that I bought the car--Nov. 29, 2006. It's really been my main topic of thought, every day, most all day!!!
I haven't been able to work since 1991 because of health problems, so conserving money is also a constant concern.
I took the car to one garage, and they charged me $70 to "check out the computer" (it's supposed to be a very good garage). Another "good" garage checked out the car, and they think the problem is "inside the engine--maybe the harmonic balancer, or something". Another supposedly "good garage", told me to either "live with it, or else get rid of the car". And on, and on and on it goes. The local Ford Dealer put in a motor mount, and that didn't help AT ALL!
So, I'm wondering if it could possibly be the engine computer, even tho' it has never had a "check engine light" come on.
Please don't tell me that they "all do this" (shake like crazy); I already have read that a hundred times!!!!

Again (as in my original post), is it possible to reprogram (or alter) an engine computer? Neither of you 2 guys have answered that question--"yes", or "no".
Thanks

[Davescort97]

Originally Posted by yahoo1

Thanks for your comments, guys! You wouldn't believe what a problem this "shaking" has been for me since the day that I bought the car--Nov. 29, 2006. It's really been my main topic of thought, every day, most all day!!!
I haven't been able to work since 1991 because of health problems, so conserving money is also a constant concern.
I took the car to one garage, and they charged me $70 to "check out the computer" (it's supposed to be a very good garage). Another "good" garage checked out the car, and they think the problem is "inside the engine--maybe the harmonic balancer, or something". Another supposedly "good garage", told me to either "live with it, or else get rid of the car". And on, and on and on it goes. The local Ford Dealer put in a motor mount, and that didn't help AT ALL!
So, I'm wondering if it could possibly be the engine computer, even tho' it has never had a "check engine light" come on.
Please don't tell me that they "all do this" (shake like crazy); I already have read that a hundred times!!!!

Again (as in my original post), is it possible to reprogram (or alter) an engine computer? Neither of you 2 guys have answered that question--"yes", or "no".
Thanks

In regard to your question, yes the computer can be set back to default values while it reprograms itself to new conditions. I don't think this is your problem, but if you disconnect the negative bat terminal for 15 minutes and then reconnect it, it should reprogram. Any time the bat terminal is disconnected, the computer takes a few miles to reprogram itself to existing conditiions.

I think your problem may be a stuck IAC (Idle Air Control). This is the part that controls the idle speed by allowing more air to pass into the engine when it is just started or is under a load. It is automatic so it can't be adjusted, but you can take it off and lube it. It is on top of the throttle body. It is a small motor with a flange on the bottom. It has 2 wires running into it at the connector. It is about the size of a C cell battery.

Take the 2- 8 mm screws out, disconnect the wiring clip and pull it off being careful not to damage the gasket which you will have to reuse. Spray it with some carburetor cleaner, let it dry, then lube it with a spray of WD-40 multi-purpose lubricant. Give a short blast of cleaner to the wiring connector. It will clean the connection to give the IAC the info from the PCM (Powertrain Control Module) which is the computer that controls the engine.

If this doesn't help you may have to buy another IAC. They are about $65 at Autozone or Advance parts places. If it is a vacuum leak this won't help it. I can't guarantee you this is the problem. It could be something else, but this is what I would give attention to first if it were me.

[AzTumbleweed]

I agree with the vacuum leak theory. Maybe EGR valve.

[denisond3]

And to answer your question about whether the computer can be reprogrammed; the answer is that yes it can be done, but it is not an elementary task, would require knowledge of the type of processor used in the computer, and of the existing parameters in the 'tuning tables'. No one is going to do it for you. As one of the provisions of the Clean Air Act, it is probably illegal to modify the 'tuning tables' in the EPROM (or whatever form the memory takes), unless the vehicle will not be used on public roads (or public land) at all, and it is certainly illegal for any one with a business license to do it for use on the highway. A violation of federal law.
At what rpm does it idle at now? The correct idle speed will probably be listed on the emissions info plate mounted somewhere under the hood or around the front of the radiator. If it idles slower than that, something needs fixed. The problem could be a large number of things: It could even be the computer; but a replacement/repaired computer would be the solution. I doubut it could be a harmonic balancer. They are meant to absorb the harmonic vibrations from the crankshaft - the sort of vibrations that happen with high rpm and high throttle openings - not at an idle.
My 92 Escort also shakes sometimes at a warm idle. I either ignore it or put it in neutral Then its smooth enough. I think mine would stop doing the vibration if I replaced all the motor mounts, the exhaust flex pipe, & rehung the exhaust system, and switched to a different oil viscosity (currently using 10w40). But I wont bother, as it runs silky smooth when moving. It also gives us 36 mpg on open roads in Texas and Mexico.
For a smooth running 4 cyl car, it would need to have countershafts inside the engine. The 2.5 liter 4 cyl. engines in the late 80s front wheel drive GM cars (like the Buick Century) had a pair of gear driven countershafts under the crankshaft. They ran as smooth as a V8, even at an idle. They were smoother at an idle than the mopar 2.5's four bangers, some of which also had dual countershafts.

[yahoo1]

Well guys, you are ALL, THE GREATEST!!!!!!!! I am truly grateful for all the effort that you all put into trying to be helpful!!! Wow! It amazes me! Based on my own experience, I know that it takes a LOT of effort to try to compose and write helpful messages. It sure is good to hear from people who care enough to put in all that effort!!!
God Bless You All!
yahoo1