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No peddle response and car has jumping revs!

Old 06-18-2010, 06:24 PM
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No peddle response and car has jumping revs!

Hay guy I just replaced my upper intake manifold and I started the car and it turns over then jumps up and down between 2000 and 3000 rpms!

Then it jumps to 3000 and stays and revs there!! Then if I give it gas all it does is drop back down and jump up and down again!

There is no response from the peddle
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Old 06-18-2010, 06:33 PM
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Strange... lets cover the basics...

Few things to double-check:
1) There is a vac line in the rear of the UIM for the vacuum chamber that supplies the SSV, AIR, and VDI solenoids. Make sure you didn't forget to connect that.
2) Make sure the purge line is inserted and secured (its the one with the blue clip that connects in the front of the UIM almost centered).
3) Make sure the electrical connection for the purge solenoid is inserted (on top of where the blue clipped purge line is inserted).
4) Check the VFAD nipple (should have a line if you have a VFAD or capped if you don't).
5) Reconnect the throttle body electrical connection. You can also verify the TB by observing the valve. Turn the key to the 'ON' position and have someone press on the gas pedal. You will see the valve open.
6) Check the MAF connection. Might also be worth it to clean it too.
7) Check the three lines just before the throttle body (probably not it, but worth a look-over).

Did your UIM come with the orange gaskets and/or did you use them?

Last edited by Jon316G; 06-18-2010 at 06:35 PM.
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Old 06-18-2010, 06:45 PM
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Yea It came with all 3 gaskets and I used them!!
My friend just turned the car on and stepped on the gas and nothing happened with the throttle body!
Forgot to mention I have an AEM intake
on the bottom of the UIM one with a green circle and one with a blue clip both are connected
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Old 06-18-2010, 06:49 PM
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Well... with the key turned to 'ON', you should have a response from the throttle body valve when the gas pedal is pressed.
This is likely what is causing your problem.
Since you just replaced the UIM, the TB is what I would focus on before the APPS (accelerator pedal position sensors).
Check the connector to the TB and verify none of the pins got bent or pushed in.
Check for any breaks in the wires themselves.
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Old 06-18-2010, 07:09 PM
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Ok I'm gonna take the throttle body out at first sight it looks bent but I'm not sure I'll take it out and look
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Old 06-18-2010, 07:16 PM
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Did you bump the MOP plug....if it is not reading right...the MOP will put the ECU into limp mode...after a reset it should work for about 5 sec.....that will confirm the limp mode thing
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Old 06-18-2010, 07:22 PM
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^Will being in limp mode prevent the APPS from activating the TB with the key in the 'ON' position?
Interesting theory with the MOP.
And after a reset (if you're right) the TB should return to normal too when you press on the pedal.
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Old 06-18-2010, 07:26 PM
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What is the MOP I did the 20 brake press reset twice and it stopped jumping but reved at 3000 and stayed! Also how do u kno ur in limp mode
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Old 06-18-2010, 07:35 PM
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Yes.......if it triggers limp mode it stays until a reset......

After a reset withthe key on....throttle works until the car is running and goes through a check routine that takes place about 5 sec after start. If it faults on first drive cycle it goes into limp mode right after that...and throttle opening is limited and the car will idle..and rev to about 3K but will allow only very small loads

This can occur with NO CEL's....and no real way to tell WTF is going on....I had his problem after a Haltech install.....I though that I had screwed something up...and spent the better part of a week of my spare time getting very intimate with the ECU, wiring harness and my scope
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Old 06-18-2010, 07:37 PM
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Originally Posted by Mr.We$t View Post
What is the MOP I did the 20 brake press reset twice and it stopped jumping but reved at 3000 and stayed! Also how do u kno ur in limp mode
Nothing happens when you push on the gas pedal
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Old 06-18-2010, 07:42 PM
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I started it a few times and I was able to rev then it started jumping and stayed at 3000 and I could gas it anymore
Lol ok so should I do another reset or what would the next step be
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Old 06-18-2010, 07:45 PM
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Not sure if resetting the NVRAM (20x brake press) clears the car from limp mode.
Might want to also reset the KAM (disconnect battery for ~10min).
Did you verify the MOP (Metering Oil Pump) connection like dannobre suggested?
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Old 06-18-2010, 07:49 PM
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I'm disconnecting the battery now how would I check the MOP
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Old 06-18-2010, 07:58 PM
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I assume dannobre is talking about the air line to the MOP nozzles.
The electrical connections are more in front of the engine next to the pump itself, so I wouldn't think its that.
I'll let dannobre clarify since he mentioned this happening with him.
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Old 06-18-2010, 07:59 PM
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The electrical connections.....

The air lines and the oil lines have no feedback to the ECU.....
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Old 06-18-2010, 08:00 PM
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Originally Posted by Mr.We$t View Post
I'm disconnecting the battery now how would I check the MOP

Do a reset and see if the throttle works before you start the car ( take off the intake bellows and look)

Start the car and see if the throttle plate stops working after 5-10 seconds

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Old 06-18-2010, 08:04 PM
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Originally Posted by dannobre View Post
the air lines and the oil lines have no feedback to the ECU.....
Thank you Mr Obvious
I was more figuring out what was near the UIM, that deals with the MOP, that he could have bumped.
The electrical connections didn't appear to be likely since it would be difficult for him to "bump" them given the location of the connectors.
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Old 06-18-2010, 08:07 PM
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Wow I just put the car on and it opened right up i'm gonna put the intake back in and c if it idles well
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Old 06-18-2010, 08:09 PM
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So it appears dannobre might have been right with it being in Limp Mode...
Now lets see if it returns...
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Old 06-18-2010, 08:16 PM
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She's back fellas I really do appreciate u guys help I woulda been screwed with out u guys
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Old 06-18-2010, 08:20 PM
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So..................what did we learn here?
Why did car go into limp mode in the first place, when changing out the UIM?
I learned that apparently the 20 brake pedal stomp won't reset limp mode, not sure I ever realized that, but I have never faced limp mode. (Knocks on wood!)

Last edited by Mazurfer; 06-18-2010 at 08:24 PM.
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Old 06-18-2010, 08:44 PM
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Lol well I learned that it's not always a mechanical issue some times it's an ecu problem :-)
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