Pontiac Montana idles high accelerates on its own

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Kimberlyhudson907
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Joined: Mon Jun 20, 2016 10:16 am

Pontiac Montana idles high accelerates on its own

Unread post by Kimberlyhudson907 » Mon Jun 20, 2016 10:22 am

I have a 2003 Pontiac Montana minivan. Idles high (2000 or more rpm) accelerates on its own ( without me ticking the gas pedal). I've already changed the idle control switch. What else can I do?

 

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carriedi
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Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: Pontiac Montana idles high accelerates on its own

Unread post by carriedi » Tue Jun 21, 2016 12:53 am

you should scan the engine data.Look to see if the fuel trims are lean. A vacuum leak could let unmetered air into the mixture so that the O2 sensor shows that the exhaust is running lean so the computer adds fuel. Extra air and extra fuel will run the idle up higher. You could get similar results if you have extra fuel entering the mix. Checking the fuel trims will tell you which way to look. Is the computer adding fuel raising the trims or is it taking away fuel lowering the fuel trim...

saltyjim12345
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Joined: Fri Feb 23, 2018 7:00 pm

ignition delay

Unread post by saltyjim12345 » Sat Mar 17, 2018 9:19 pm

My 2003 Pontiac montana 3.4 v6 has a ignition delay problem.this morning,i got in,turned the key,and it started immediately.Five minutes later,after stopping for a few minutes,I turned the key and had to wait 35 seconds for the starter to kick in.This varies from 2 seconds to one and a half minutes.The fuel pump,filter and relay have all been changed,to no avail.Hot or cold,no matter.

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carriedi
Posts: 2267
Joined: Wed Apr 10, 2013 12:42 pm
Location: Oregon

Re: ignition delay

Unread post by carriedi » Sun Mar 18, 2018 4:13 pm

your igintion switch sends a signal to the Powertrain Control Module (PCM) and the PCM then sends a signal to your starter relay. The starter relay allows the starter solenoid to power up and get the starter going. you will need to check each part of those circuits to find out where the delay is.

Yellow wire out of the ignition switch that goes the the pcm/crank 10A fuse in the right side dash fuse box.
Purple wire from the fuse to pin 23, connector 2 in the pcm.

Yellow/black wire from the pcm (pin 76 connector 2) to the starter relay. This will be a ground wire that the pcm grounds to turn the relay on.

the relay should power up the purple wire that goes from the relay to the starter solenoid.

to find out where the problem is you should have each part or the starter system monitored to see where the delay is at. I use a box that has a bunch of led lights I can tie into each section and then I can see what lights up and when. Normal condition they will all go on at about the same time. Without checking all the parts of the circuit at the same time it will be difficult to see what is causing the delayed start.

you could just try a starter relay. Sometimes the relay will have a bad connection through the points that go from power to the starter solenoid.

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