Idle Out of Control (IOC)!

93 Lumina (VIN T)

Problem ( Persistant 1.5 years)

When I initially start her up, she idles like no tommorow. I have no TACH so I have no idea what RPM she's at. I let the oil pressure build up and then I put it in gear. Funny thing is, I can still feel the motor pulling hard yet it seems quieter/slower. After I get to where I want to go (roughly 20 min drive), and I put it back in park, she seems normal. Then I shut it off. I come back and the idle is back up again. Does not matter if it's cold/hot. I've struggled with this long enough, and searched long and hard, for answers. And this is what I have done:

R/R

spark plugs
O2 sensor
Idle air control valve
air filter
pcv
oil/filter

I am in need of help soon as the Maine winter will take it's toll on this high idle badly.

Please help,
tony

I would try to clean out the passage way for the IAC. Where did you get the IAC from? I'm leary of electrical parts from Autozone. I had a IAC come apart on me...... good things I was close to home.
I would also relearn the idle process.

I cleaned out the entire passageway of the IAC except i did not get into the actual throttle body. I was thinking about doing that but, then i realized how much work it would be and how little time i had. I'm not quite sure the throttle body being dirty is the problem though.

I have searched everywhere for vaccum leaks and only found one. It's the Cruise control vaccum. Has nothing to do with Idleing.

As for where I bought the IAC. I bought it at Advanced Auto Parts. I have never, never, never had any problems with them.

Now, the chiltons does not exlplain anything about the relearn process. Or maybe I overlooked it in my drunken/sleepy daze.

Please explain the re-learn process. I will google it also.

many, many, many, thanks

what is the easiest/safest way to the iac passage way. i have recently replaced the iac and lately when i start my car it idles at 2000 rpm's. i pulled the positive cable for the battery to reset everything, so far so good. also when i stop at a light the idling is going up and down for a fews seconds then it levels out(goes up and down between 500 and 1000 rpm's, then levels out just above 500 rpm's). what is a normal rpm range?
93 lumina eurosport sedan 3.1 v6 131,000 miles.

thank you everyone.

Google is so much fun!

For all who do not know!

Idle Relearning

http://www.xse.com/leres/efidiag/idlelearn.html


I'm going to try this, and see if this solves my problem.

thanks again

The Idle Re-Learn Trick did not work.

Just last night I did a lot of work to this baby.

I removed the throttle body, the egr, and the upper plenum. For possible vaccum leaks I replaced the throttle body gasket and the two egr gaskets. I also cleaned everything up (from the throttle body all the way into the deep crevices of the plenum), I even painted the upper plenum, to make it look all nice and purrty.

One more think I did was the Throttle body Coolant Bypass.

I reinstalled all of it back with in a hour or two. No problems what so ever. Easy as counting One, Two, Three.

Then........

I reconnected the battery, Turned the key on for ten seconds then back off. Then I started the car. Kind of hesitant at first, but she purred like a kitten. She was Running beutiful. This was about 1 A.M. this morning.

So, I wrapped things up happily. I went to sleep knowing I fixed the problem.

But.........

This morning (6 A.M.) I hopped in, low and behold, she was Idleing high again. I don't know what to think anymore. I got the Check engine light on with the paper clip code of 35.

One thing I regret doing so far is not replacing the Upper plenum gasket (I was short on 35 bucks) and using fuel injection cleaner to find vaccum leaks.

Anyone else have any Ideas?

I need help, pretty badly.

I'm just a little anxious

Did you fix the vacuum leak at the cruise control that you mentioned?

Yes, the cruise control vaccum leak has been stopped. The tube dried up and broke. Located at the FWD Driver side of the vehicle. Right near the bumper. The tube connects into something that looks like a hollow ball. I don't know what it is called, but that is where the leak was at. Fixed now.
Still haveing Idleing problem.

The ball is the vacuum resevoir. They leak sometimes too.

I sprayed some soapy water (very unsafe) on all vaccum lines with no sign of any leak or spray back. All vaccum lines look fairly decent, now that I changed the cruise control vaccum line.

Any other ideas?

I don't want to give up.

mine was caused by a very low tech issue: the kick panel below the dash was keeping the accelerator from going all the way back. but most of the fast idle problems are usually IAC, IAC pathway, or residue building up on the throttle plate

Ok, I got some Fuel Injection Cleaner and searched for leaks the right way with no joy what so ever.

Now, since I worked on removing / cleaning / replacing the throttle body / plenum / EGR, I have a paper clip code of "22" (Throttle Body Sensor) along with the same code I had originally "35" (IAC). So, I'm sure most of you are feeling my pain of frustration, knowing I have to R/R a 30$ Part now because I ruined the damn thing when I got it wet probably.

So, Please, if anyone, has any information for me, that would help me through this rough time of mine, please, don't hesitate to reply.

Thanks for your concern,
tony

I sprayed some soapy water (very unsafe) on all vaccum lines with no sign of any leak or spray back. All vaccum lines look fairly decent, now that I changed the cruise control vaccum line.

Any other ideas?

I don't want to give up.

What about a low grade electrical short which drains your battery ? and when you start up, your computer compensates for the drain by speeding engine up to recharge low battery. I had a short in my 95-3.1 that did the same thing, really idled fast on startup and stayed fast for a long period until battery charge caught up. I parked it for a couple days and drove my truck and then when I went to start the 3.1, battery was dead . I had never noticed short before then because I had driven it every day, so it always had enough remaining juice to start .. Found the short is somewhere in the chime module circuit, so unplugged fuse and have normal idle and never have dead battery since, just no memory in radio or door open/lights on chime. My be worth investigating to eliminate this possibility...?

[QUOTE=Marlamar]What about a low grade electrical short which drains your battery ? and when you start up, your computer compensates for the drain by speeding engine up to recharge low battery. I had a short in my 95-3.1 that did the same thing, really idled fast on startup and stayed fast for a long period until battery charge caught up.[QUOTE]

I checked for bad grounds and shorts in electrical wires last weekend with no joy unfortunatley. But, I did check again last night, with no joy. Also read out the battery at 12.08 volts w/out engine on and 14.06 w/engine running. Now as for letting the vehicle sit for long periods of time, I did not start it up last weekened. So I think if it is elecritcical problems causing this, then it would be a strong enough short to drain the battery with in 24 hours. Great idea though.

Take the ECM to a parts store with a tester, see if they can spot something corrupted in it's operation. You said it seemed OK after the idle relearn, then went back to incorrect operation after restarting, as if something is corrupting the open loop run strategy after one cycle?

Jeff, That sounds like a great idea.

Is there any problems i would have. Is it really easy to bend the pins on the ECM? I noticed the ECM is a little tough to get to because the radiator overfill is mounted right there.

I am a little sketchy about messing with something that is so expensive, but, If I can troubleshoot down to the ECM Replacement, then, I will just sell the car and notify the buyer of the ECM problem.

Does anyone have any problems with messing with the ECM at this point. I am just to affraid to mess with it right now.

are you sure you have found the ecm? I havn't heard of one being anywhere near the radiator overfill. I'm not sure exactly, but isnt the ecm in the drivers side kick panel inside the car? Um, it should just be a few plugs and screws to take out. Pretty straight forward.

take a look at that black plastic housing that sits on the passenger wheel well, you will see two metal clips that hold the top on. it also looks like there is a vent going from the headlights to the ecm in order to cool it? once you remove the cover, you'll see a silver metal module about 5"x5" by about 1.5" thick. I'm supposing this generates heat is why they put it there instead of the passenger compartment, where it could be better protected from teh elements...

http://img.photobucket.com/albums/v485/kevinb70/lumina/pcm.gif

No problems, really, just unplugs. Lotsa pins but the connectors are made in a way that they have to slide straight apart so it won't damage them.

The parts store I used to work at just got a tester that will do ECM's, so I haven't seen it in action, but they say it works real well, and has cut their incedence of customers trying to return them because that wasn't their trouble.

I don't know if you still have to change the chip on the new ones over to the replacement, you used to. You just have to take care to be static free and very careful to push it in dead on so nothing gets bent up.

Powertrain Control Module (PCM) Replacement/Programming

PCM REPLACEMENT/PROGRAMMING

CAUTIONS:


In order to prevent possible Electrostatic Discharge damage to the PCM, Do Not touch the connector pins or the soldered components on the circuit board.
Turn the ignition OFF when installing or removing the PCM connectors and disconnecting or reconnecting the power to the PCM (battery cable, PCM pigtail, PCM fuse, jumper cables, etc.) in order to prevent internal PCM damage.
NOTES:


Service of the PCM should normally consist of either replacement of the PCM or EEPROM programming. If the diagnostic procedures call for the PCM to be replaced, PCM should be checked first to see if it is the correct part. If it is, remove the faulty PCM and install the new service PCM.
The Crankshaft Position System Variation Learn Procedure should be performed if:
The PCM has been replaced.
The PCM has been reprogrammed. See: Crankshaft Position System Variation Learn Procedure
IMPORTANT: When replacing the production PCM with a service PCM, it is important to transfer the broadcast code and production PCM number to the service PCM label. Do not record on PCM cover. This will allow positive identification of PCM parts throughout the service life of the vehicle. THE SERVICE PCM EEPROM WILL NOT BE PROGRAMMED. DTC P0602 indicates the EEPROM is not programmed or has malfunctioned.

REMOVAL PROCEDURE


Disconnect the negative battery cable.
Remove the left strut brace.
Remove the air cleaner housing cover and the PCM from the housing assembly.
Disconnect the harness connectors from PCM.
Remove the PCM from the engine compartment.
INSTALLATION PROCEDURE


Install the connectors to the PCM.
Install the PCM into the air cleaner housing cover.
Install the air cleaner housing cover.
Connect the negative battery cable.
If a new PCM is being Installed, program the EEPROM.
The PCM will need to learn the crankshaft variation. Refer to CKP System Variation Learn Procedure.
EEPROM PROGRAMMING


Set-up - Ensure that the following conditions have been met:
The battery is fully charged and a battery charger is not connected.
The ignition is ON.
The Techline equipment cable connection at the DLC is secure.
If the BCM has been replaced the PCM must relearn the Theft Deterrent password. Refer to BCM Replacement/Programming procedure.
Program the PCM using the latest software matching the vehicle. Refer to up-to-date Techline equipment users instructions.
If the PCM fails to program, proceed as follows:
Ensure that all PCM connections are secure.
Check the Techline equipment for the latest software version.
Attempt to program the PCM. If the PCM still cannot be programmed properly, replace the PCM. You must also program the replacement PCM.
FUNCTIONAL CHECK


Clear DTCs.
Perform Powertrain On Board Diagnostic (OBD) System Check. Refer to Powertrain OBD System Check.
Start the engine and run for one minute.
Scan for DTC(s) using the scan tool.

Crankshaft Position System Variation Learn Procedure

The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If the actual crankshaft position system variation is not within the crankshaft position system variation compensating values stored in the PCM, DTC P0300 may set (refer to Diagnostic Aids for DTC P0300).

The Crankshaft Position System Variation Learn Procedure should be performed if any of the following conditions are true:



DTC P1336 is set.
The PCM has been replaced.
The PCM has been reprogrammed.
The engine has been replaced.
The crankshaft has been replaced.
The crankshaft harmonic balancer has been replaced.
The crankshaft position sensor has been replaced.
IMPORTANT : The scan tool crankshaft position system variation learn function will be inhibited if engine coolant temperature is less than 70°C (158°F). Allow the engine to warm to at least 70°C (158°F) before attempting the crankshaft position system variation learn procedure.

The scan tool crankshaft position system variation learn function will be inhibited if any powertrain DTCs other than DTC P1336 are set before or during the crankshaft position system variation learn procedure. Diagnose and repair any DTCs if set.

The crankshaft position system variation learn tunction will be inhibited if the PCM detects a malfunction involving the camshaft position signal circuit, the 3X reference circuit, or the 24X reference circuit.



If the scan tool indicates a problem with the Cam signal, refer to DTC P0341 CMP Sensor Circuit Performance.
If the scan tool indicates a problem with the 3X crank signal, refer to DTC P1374 3X Reference Circuit.
If the scan tool indicates a problem with the 24X crank signal, refer to DTC P0336 24X Reference Signal Circuit.
Set the parking brake.
Start the engine and allow engine coolant temperature to reach at least 70°C (158°F).
Turn OFF the ignition switch.
Select the crankshaft position variation learn procedure with the scan tool.
Proceed as instructed by the scan tool. If the procedure is terminated, refer to Important above for instructions.
Observe DTC status for DTC P1336.
If the scan tool indicates that DTC P1336 ran and passed, the crankshaft position system variation learn procedure is complete. If the scan tool indicates DTC P1336 failed or not run, check for other DTCs. If no DTCs other than P1336 are set, repeat the crankshaft position system variation learn procedure as necessary.

Testing and Inspection

POWERTRAIN CONTROL MODULE DIAGNOSIS
To read and clear diagnostic trouble codes, use a scan tool. Use a scan tool to clear diagnostic trouble codes from the PCM memory.

The Vehicle Identification Number (VIN) is programmed into the PCM. Do not exchange a PCM from another vehicle for testing or replacement. When replacing the PCM, the VIN must also be programmed into the new PCM.

Because the PCM can have a failure which may affect only one circuit, follow the diagnostic procedures in this section to determine which circuit has a problem and where it is.

TROUBLESHOOTING
If a diagnostic chart indicates that the PCM connections or PCM is the cause of a problem and the PCM is replaced, but does not correct the problem, one of the following may be the reason:



There is a problem with the PCM terminal connections. The diagnostic chart will say PCM connections or PCM. The terminals may have to be removed from the connector in order to check them properly.
EEPROM program is not correct for the application. Incorrect components may cause a malfunction and may or may not set a DTC.
The problem is intermittent. This means that the problem is not present at the time the system is being checked. In this case, refer to Symptoms and make a careful physical inspection of all components and wiring associated with the affected system.
There is a shorted solenoid, relay coil, or harness. Solenoids and relays are turned on and off by the PCM using internal electronic switches called drivers. Each driver is part of a group of seven called Output Driver Modules. A shorted solenoid, relay coil, or harness will not damage the PCM but will cause the solenoid or relay to be inoperative. The J 34636 tester, or equivalent, provides a fast, accurate means of checking for a shorted coil or a short to battery voltage.

[QUOTE=Marlamar]What about a low grade electrical short which drains your battery ? and when you start up, your computer compensates for the drain by speeding engine up to recharge low battery. I had a short in my 95-3.1 that did the same thing, really idled fast on startup and stayed fast for a long period until battery charge caught up.[QUOTE]

I checked for bad grounds and shorts in electrical wires last weekend with no joy unfortunatley. But, I did check again last night, with no joy. Also read out the battery at 12.08 volts w/out engine on and 14.06 w/engine running. Now as for letting the vehicle sit for long periods of time, I did not start it up last weekened. So I think if it is elecritcical problems causing this, then it would be a strong enough short to drain the battery with in 24 hours. Great idea though.

Only 12.08 volts? This seems kind of low to me. Shouldnt it be around 12.6 area when not running? Um, was it just cehcked with a voltmeter, or did you actually load test it with a VAT-40 or something? I maybe on a hunch would take the battery out and bring it to a shop to have them load test it. That seems low to me for a healthy car with a good alternator. How often is this car driven?

hey kevin, are you sure he has to go through all of this? Its a 1993 Lumina with OBD1, not OBD2.

oh eeek... i got this confused with the 97 lumina thread!!! sorry

and how do you have a 2001 lumina?????

its the last year they made them, they phased them out to start the impala in 2001. Why does that seem odd?

Only 12.08 volts? This seems kind of low to me. Shouldnt it be around 12.6 area when not running? Um, was it just cehcked with a voltmeter, or did you actually load test it with a VAT-40 or something? I maybe on a hunch would take the battery out and bring it to a shop to have them load test it. That seems low to me for a healthy car with a good alternator. How often is this car driven?



Load Test Checked Good at Advance Auto Parts. Tested the alternator also. That checked good also.

I drive the car every single day, minus a day or two on the weekends, back and forth to work. The baby runs great except for this idleing problem.

Oh, and by the way it is an OBD I if anyone has any doubts.

I really appriciate all the feed back I've been getting here. Should I just sell the car, or what, hah hah.

I'M NOT GIVING UP ON THIS SMALL PROBLEM SHE IS HAVING.

I thought 1999 was the last year for the Lumina, and that the 1999's were mainly fleet vehicles... I honestly didn't know there were 2000 and 2001 models... just checked autozone and see now there were vin J's... 3.1L only...

yes sir, Its basically a 1998 lumina or 97 or 95, all are the same in my book. They all have the same motor and same body style, hardly no changes that I can see.

its the last year they made them, they phased them out to start the impala in 2001. Why does that seem odd?

In 2000 when I bought the Impala, I actually wanted another Lumina, but they didn't have any, and said they wouldn't be getting anymore. They did say I could order one, but that Impala was sitting there screaming "Buy Me, Buy Me!" :grinyes:

wanna trade? I love impala's, I wish I had the kind of cash for one. The chevy garage in town has the nicest black Impala SS, I just drool over every time I drive by. But anyways, buck to the post, I would check the iac motor again, and make sure the plug and wires are in good shape, maybe exchange it (this doest work, can I exchange for another one) And see if that helps, maybe when you plug it in, spray the plug with wd40 or something, and make sure its seated right. Also I still think that there could be a vacuum leak somewhere, maybe get a vacuum guage hooked up and check for that. Your probably thinking "I;ve already tried all that", but thats all I have. Sorry strange one here. Good luck. Is it a constant very high idle, or does it increase very slowly, or is it like an idle like where someone has mashed the pedal to the floor. I had a high idle for a while in my 90 lumina, it wasn a pedal mashed high idle, but it was up there. It seemed to go away, so I thought nothing of it, sorry i cant be of better help. Good luck.

what about a throttle position sensor?

wanna trade? I love impala's, I wish I had the kind of cash for one. The chevy garage in town has the nicest black Impala SS, I just drool over every time I drive by. But anyways, buck to the post, I would check the iac motor again, and make sure the plug and wires are in good shape, maybe exchange it (this doest work, can I exchange for another one) And see if that helps, maybe when you plug it in, spray the plug with wd40 or something, and make sure its seated right. Also I still think that there could be a vacuum leak somewhere, maybe get a vacuum guage hooked up and check for that. Your probably thinking "I;ve already tried all that", but thats all I have. Sorry strange one here. Good luck. Is it a constant very high idle, or does it increase very slowly, or is it like an idle like where someone has mashed the pedal to the floor. I had a high idle for a while in my 90 lumina, it wasn a pedal mashed high idle, but it was up there. It seemed to go away, so I thought nothing of it, sorry i cant be of better help. Good luck.




Thanks tblake,

I still think there maybe a vaccum leak also. I didn't know of any tool that measures for vaccum leak. Do you have any idea of what it is called exactly and where I may be able to find/buy one?

Yes it is a constant idle, until I drive it for a while then it calms down. And it's a idle that's like a pedal about half way to the floor. but the throttle arm stays in the idle position. It does it right when I start it up, especially the first time i start it for the day.

Anyway, I am conviced there has to be a vaccum leak somewhere, unless someone else has any ideas

Thanks for the help,
tony

i actually had the same symptoms in my lumina (93 eurosport 3.1 v6) i changed the iac, for about two weeks it was fine. then when i would start it up the rpm's would run about 2 1/2-3000 rpm's. i was told that the computer was confused, and i needed to reset it. unplugged the battery for about 5 min., started driving at about 40mph for roughly 10 min., then got in the freeway punched it to about 80mph. afterwards every seemed to smooth out. i never actually tried the relearn process, just usaully drive for a good twenty minutes at various speeds. good luck.

yeah, I think its just called a vacuum leak testor. Thats what i call it anyways. They may be kinda expensive, and there is a certain procedure for checking vacuum with one of these, I'm not exactly sure, someone knows on these boards, or else just have a mechanic friend do it. good luck

For everyone that was involved with me troubleshooting this ridiculous gripe, I want to say thank you.

I told everyone I would not give up, and that is just what I did. I never gave up, and I fixed the problem.

This is what I did to TRY to fix this gripe:

Replaced:

IAC
Spark plugs
Spark plug wires
All three Coils
TPS
All Vaccum Lines

All this totalling Over $100

This is what I did to FIX this gripe:

Replaced:

MAP Sensor

Totalling $2 from junk yard



ONCE AGAIN, THANKS EVERYONE!!!!!!!


Now the God Damn Power steering Pressure line sprung a leak.
Caused me three stitches trying to get the line out. Check out my newest post.

what part stores have an ecm tester
auto zone doesn't
i do not think napa does either
i'd like to know

So The MAP eh? I guess that was just a guess? I'm going to give that one a try. Is you idle still good?

Cheers!