411 Code and High Idle

The cooling fan only come on when the engine becomes hot, and then shuts off when cooled. There is no change when the IAC is unplugged. Nor is there any when the throttle cable is disconnected. Now, the t-body lever can not go back any further than at its idle state. I even adjusted the screw to see if it would go back and it left a gap between the screw and the stop plate. The transmission shifts fine through the gears, but when it comes to stopping there is a thump coming out of first gear. If I pop my foot off the brake or a quick lock of the brake in a non moving state car in overdrive gear the tranny will bang in and out of gear. When I told the guy at AAMCO of this he said he made an adjustment to the "SPRING TENSION" so it should be okay. Well. It ain't. Anyway Justanold, the ball is in your court. I'm ready for round two. Thanks for all of your help and skills. Jimmy

Unplugged the cnaister hose to purge selenoid and plugged it up as asked. Started engine and noticed immediate lower rpm's as engine began warming up. Around 900 rpm At one point it read a low of 888 rpm. As engine reached its first fan cycle at 214 degrees the rpm registered and maintained a level of 965 to 980. A decrease from the reading of 1024-1045 before performing the test. Back to justanold.

Left vac line plugged, already own cans of carb cleaner, and rescanned after egine warmed. Still showing the 411 code. Also 536 code which deals with the brake depressing and release not being recognized during test. You asked about the EGR being replaced and the answer is yes. All parts are from ford except the cat converter which I got from Autozone. The one thing I did not mention before is the fact that when I step on the accelerator the rpm does not return as fast as it should. This of course sounds like a leak somewhere. Back to you.

For the past two days I have checked and rechecked all vacuum lines possible. Changed a couple of hoses that looked worn and still there is no change in the idle. I reran the scan and still come up snake eyes. As I stated before, the AAMCO boys from Mexico left one of the sensors upnplugged that was clearly visible to the eye. I am still wondering if there is one somewhere that I can't see that is still unplugged. In my searching I came across one possible sensor that comes off of the harness that is located right below the air fillter and runs under the throttle body to the rear of the engine. This harness also holds the rear Oxygen Sensor line. The unplugged item has the shap of a cigar. Then there is another one I located that is tucked behind the windshield wiper motor. This one appears to have the shape of that of an Oxygen Sensor. Can you tell me if these are suppose to be connected to something, or are they for some sort of test purpose? Back to you.

Put in new ECT sensor and pinched off the hose to the brake booster, but no change. Before I go any further last week I noticed my right side brake acting funny when I would apply it at speeds of 40 miles per hour or more. It was a pulsating reaction. I knew it could not be the rotors because they're only one year old, and I don't over-tighten the lugs. But maybe there is a leak so small that is screwing up the rpm? The tranny is a AXOD 17 bolt pan. I havee a multimeter so now. Back to you.

Disconnected battery for two hours, reran scan and still have 411 code. I than ran the electrical tests first measuring the IAC solenoid resistance that came up at 9.9 ohms. The second test was for internal short to IAC solenoid case which came back at 0.00. No short present. The third test was to check VPWR circuit voltage which came back at 0.2 volts. Back to you.

Battery reads: 12.47 volts. Red Lead (+) to Red Wire at IAC connector and Black Lead (-) to negative battery post reads: 0.00 volts. Also tried Red Lead to White Wire and Black Lead to negative battery post with same results. When I tried Red Wire to positive battery post I got the 0.2 volts reading. Same reading with White Wire to negative battery post. I'll try to see if I can get an answer about the pressure line from the tranny question as you aked. Back to you.

I am the person who had the issue of the idle problem some time ago. I finally found out what the problem was when I went to change my engine oil.
As you may or may not know this problem started when I took my car in for a check-up on a transmission repair issue at AAMCO in Queens, New York. When I returned to pick up my car the idle was crazy. The owner said he knew nothing about it and would not address the matter at all
After going over the car and finding several issues (front motor mount bolts finger tight, plastic band used to reconnect CV boot to halfshaft, busted control arm and bushings put on backwards, ect), I went about doing the repairs on my own.
With the idle still remaining high, I went to change my oil, there it was.
The oil was replaced with transmission fluid. ALL OF IT !
The problem being that this engine already had over one hundred thousand miles on it, all of the worn areas in the engine were now cleaned out by the tranny fluid thus allowing for no seals in the pistons and allowing blow by and loss of compression.
I am now happy to say that after a few thousand new miles and the use of oil additives to help seal back the engine the idle has woked its way back down to normal.
I do want to thank everyone for their feedback and suggestions. I hope that this can bring about a quick answer to anyone with a similar situation.
I do not want to bad mouth AAMCO but when I went back with the halfshaft with plastic tie in place I was told by the owner that that was a normal repair and as for the rest of the issues with my car he fired the mexican worker who worked on my car.
So as always. Let this be a word of caution to all. And take a wrench into your own hands. It'll save you a lot in the long run.