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Idle relearn


rockfangd

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I can only thing that this is due to the new intake, checking the P0507 again (that is what you are getting correct?), they said to check for vacuum leaks. I posted this before, but there is not much that can go wrong besides the PSP which you jumped. How are the gaskets/seals between the intake and the throttle body? When this high idle occurs can you turn the engine off and look to see if the throttle plate is closed?

Visually/physically inspect for the following conditions:

  • Throttle body tampering (adjustment screw).
  • Restricted air intake system. Check for a possible collapsed air intake duct, restricted air filter, or foreign objects blocking the air intake system.
  • Throttle body. Check for objects blocking the IAC passage or throttle bore, excessive deposits in the IAC passage and on the pintle, and excessive deposits in the throttle bore and on the throttle plate.
  • Vacuum leaks

yes the P0507 is the only code.

I have checked the throttle plate, I even just tried to change the set screw on the TB but it was already to the minimum setting.

I cannot locate any vacumn leaks at all, unless somehow it is internal in the intake.

I do note that when you start the engine that instead of the engine idling down it slowly idles upward, till about 950-970RPM.

I rechecked th throttle plate and it seems to be closing properly.

GM FAN FOREVER

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Very frustrating

When the PCM goes into closed loop the engine should idle down to normal levels. Since you are not getting any other codes, we have to assume that you are going into closed loop. Do you have a method of determining that?, computer or scanner? My Autotap, tells me open loop/closed loop. That, said, I don't think this is a symptom of open loop, it will stay high for a minute or so then drop to normal, this is an escalating idle, which is somewhat different.

The odd thing is that this occurs as the engine warms, and changing the intake manifold gaskets made no difference. It is something that is either opening up to let more air in as it gets hotter or something telling the PCM to step up the idle.

This has only occurred since changing the intake...hmm

You did swap out the IAC correct?

Hmm, maybe I found something..... I went to www.rockauto.com, I looked up a 97 SLS and I looked up the IAC for that car.....when I clicked the part number it said that THAT IAC was only good for the 96 to 98! Is there something DIFFERENT about the 1999 SLS when it comes to the IAC....

Please look into that...

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

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To make matters worse, I went to the 99 Seville and it takes the same IAC part number 17113388, and when you click on that part number it states 96 to 98. It may be nothing at all, but I still would look into the matter.

Ok, now go to rockauto and look at intake manifolds under engine, I get the same type of problem for an 99 SLS it states 95 to 98, now maybe the years are wrong but its something to look into.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Man this is odd, I went to AC DELCO.com and punched in the IAC part number 17113388 and I get that it is good for 1996-1998 SEVILLE STS....why not the 1999?

Same thing with the intake on AC DELCO, look up the 1997 SLS and the intake part number is 12497989 and its only good for the 95 through 98 SLS and STS and others but what is different about the 99?

This may all mean nothing but you have such an odd problem that its worth looking into.

However the major change took place in 2000, why 1999 is different, I dont know

Do you have a 1997 service manual?

Is it possible to flip the IAC plug to reverse it? by accident?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Man this is odd, I went to AC DELCO.com and punched in the IAC part number 17113388 and I get that it is good for 1996-1998 SEVILLE STS....why not the 1999?

Same thing with the intake on AC DELCO, look up the 1997 SLS and the intake part number is 12497989 and its only good for the 95 through 98 SLS and STS and others but what is different about the 99?

This may all mean nothing but you have such an odd problem that its worth looking into.

However the major change took place in 2000, why 1999 is different, I dont know

Do you have a 1997 service manual?

Is it possible to flip the IAC plug to reverse it? by accident?

Ok the Iac is for the 97.

It is not possible to install the IAC plug backwards

IT does go into closed loop according to my scantool.

That is very weird. Both inntakes looked identical, but maybe something did change. As I stated before the manifold pressure sensor is different on the 99. Maybe I should install the sensor from the 99?

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Yes, I would look into that pressure sensor. The reason, I looked at rockauto was to try to uncover everything, yes check that sensor

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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well not so bad today. I went 20 miles today and the light wet out on its own enroute. It seems if I put it right into gear after startup it idles better,

When I put it back into park I shut it down, and by doing this the light has gone out. I am not going to get my hopes up yet though. Not sure how long it is supposed to take to learn the idle

GM FAN FOREVER

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About 5 minutes is all it ever took me with my 96, high idle was never an issue. It sounds good however, hope this lasts

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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no issues on my 96 either. When I did my TB and Egr. it just worked

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Well I unfortunately have to say it is not often I admit defeat, but I give up.

Was driving today and stopped at my bank. Put it in park, and sure enough the SES light came back on and the idle steadily increased to around 975. 850 in gear.

So I went to my dealer and they want alot for electrical Diag. and I just dont have the money. So I bought a pcv valve(I wanted the pipe with elbow but it is days away).

Came home and in changing the pcv valve I noted that the elbow was cracked. So I replaced the elbow with a new one I had.

I really had my hopes up but it did nothing to solve the problem.

I pulled and inspected every pipe, elbow, and tube, found nothing

Pulled the IAC, inspected the port. Replaced the original IAC valve.

Started the car and unplugged the IAC, Installed noid light on the plug. Noted both lights are on all the time. (dont know if this is supposed to be like this but it verifies power on both circuits)

Switched out map sensor with the one from the replacement intake.

Nothing I did made any changes.

So For now I have had enough.

I can only think of 2 options

Put back on original intake and hope problem goes away

Take it to the dealer and pay them to hope they can figure it out.

Also have to note that dealer pulled numbers for the intakes, said 95-99 are all the same part number, and same with the map sensor

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Yes frustrating, glad you checked the intake part numbers

That EGR elbow sounded promising

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Yes frustrating, glad you checked the intake part numbers

That EGR elbow sounded promising

Not EGR elbow, PCV elbow.

I am mainly frustrated because I have a long trip tomorrow and cannot use it, also just dont have much money right now.

I have some repairs to do on the Deville but have to keep driving it

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Oh my slip up, that is what I meant, that is direct vacuum loss, and would lead to fast idle, how is your PCV could it be bad? Did you shake it?

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 2 weeks later...

Well today I gave in and will be taking the car back to the dealler and praying I can afford to find out what the problem is. they say it definately doesnt seem like it could be the intake but if it is I will not be happy. But all I want to do is figure it out.

I will post my results. I am going to go over it one more time saturday bbefore I take it though just in case

GM FAN FOREVER

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Ok dealer called tonight. Said it is all fixed. I have to say I felt really dumb but mistakes do happen.

The throttle body gasket was installed backward. $120 lesson. I didnt know what to say. The good news is that the intake is fine, before I sent thhe car I relaced the pcv valve and the elbow with pipe. The tech said the IAC counts were right around 30 at idle which is perfect.

Now I really hope to not have anymore problems for awhile.

Next task, replace the bumper and do some body work to my Deville

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Glad to hear it

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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That would be the source of the vacuum leak that was causing the high idle.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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well great news. The car runs excellent. I say worth every penny. Next year the transmission needs some attention and this car will be as good as it looks

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Glad to hear it

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 4 years later...

Ok dealer called tonight. Said it is all fixed. I have to say I felt really dumb but mistakes do happen.

The throttle body gasket was installed backward. $120 lesson. I didnt know what to say. The good news is that the intake is fine, before I sent thhe car I relaced the pcv valve and the elbow with pipe. The tech said the IAC counts were right around 30 at idle which is perfect.

Now I really hope to not have anymore problems for awhile.

Next task, replace the bumper and do some body work to my Deville

I have read all the topic about your past problem (P0507 code). I have the same now with my seville 1999. You said that the reason was the gasket but I dont know how could you install it backward - http://ecx.images-amazon.com/images/I/71H9Q6A2I-L._SX450_.jpg

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Welcome To Caddyinfo.

You know I am not sure. It was over 4 years ago.

I have never had it happen before but that is what the dealer said was wrong. I have to be honest it should be pretty easy to make sure it is installed properly. Next time I go to do one (Just bought another Deville) I will post a picture of it both the right way and a possible wrong way if there is one.

Thank you for taking the time to read some threads, You can learn quite a bit

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Who knows if the dealers statement was accurate, it does not look like it can be installed backward. I had a mechanic state I did something wrong a few years ago on my Monte Carlo, seemed hard to believe but it happens when you are rushed and under pressure I suppose. I find that mechanics like to criticize other mechanics so who knows.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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If you install a head gasket backward (assuming the bolt pattern would line up), you're either on drugs or drunk.... The chaincase is on the right side of the engine - if you install the head gasket 180° off, the chaincase portion wouldn't be sealed and there'd be a big chunk of gasket exposed.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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