Radical Idle Problem - Running Out of Options - HELP

[tomtom123]

What year is your car?

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[CNorell145]

2000 Grand Prix GTP.

[tomtom123]

This the diagram you saw?


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[CNorell145]

Yup, that's the one. Don't tell me it's the wrong car...

[tomtom123]

This is the one I use. Looks a bit different from the other one


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[CNorell145]

Hmmm, I'll have to recheck the vac lines based on that diagram.

Hopefully I get off wok before the thunderstorms, and can snap some pictures.

[Scottydoggs]

the tree atop the supercharger in the diagram shows two unused ports, the fat one goes to the brake booster, the other thin one goes to your hvac, its a vac line thats screwed to the pass side fire wall.

see the line on the pass side fire wall.



new lines and T's





this is my evap vac line repair, the old one cracked in the middle of the hard bend, used a fat line that fit the TB then a smaller one pushed inside the fat one, then to the stock hard line.




on the right side of bbv, theres a open port too. it came with a foam filter on it, but most have fallen off by now, so if thats open its normal.

[CNorell145]

Does it matter which side the vac line is hooked up to on the BBV?

[Scottydoggs]

Does it matter which side the vac line is hooked up to on the BBV?

not sure what you mean. post a pic or describe it better please.

[CNorell145]

On the one side of the boost bypass solenoid, you should have a vac line hooked up to one of the nozzles, and the foam in the other. Does it matter which side the foam is in vs the vac line? (Mine has three total nozzles on the BB solenoid) if that still doesn't make sense I'll try to get a picture ASAP

[Scottydoggs]

the one that would of had the foam filter on it has a odd looking metal clip there. that one stays open.


found a pic, this should be open

[CNorell145]

Alright, I'll check and see if mine is hooked up correctly.

Do the PVC's often go out on these cars?

And tom, I don't remember seeing that on my tranny, I'm sure I just missed it, should that have a vac line running to it?

[Scottydoggs]

im not aware of any vac line to the back of the tranny. not sure what that is in his pic.

[CNorell145]

Well, just drove the car home from work, and now it is knocking big time and the boost gauge won't read above 0 when I step on it... Any ideas there? Would that be related to the idle issue?

EDIT - it is even knocking at idle now when the engine revs up to about 2k

[CNorell145]

One thing to note, there was a big coolant leak, the lower radiator hose came off... I put it back on and replaced the coolant... It only went about a minute tops without coolant.

[CNorell145]

Oh, also the boost gauge reads 1 PSI when I blow into it, so that is working fine.

[tomtom123]

Sorry. Was at work. The picture I posted of my tranny with that silver nipple I was going to mention I don't know of anything that attaches to that. Its just there.

MAP sensor will cause all kinds of weird problems with the car reading boost. The car has to be able to read the barometric pressure outside in the atmosphere to properly know what to do with itself. So check your MAP sensor to make sure its plugged in. Refer to the diagram I posted earlier to find the MAP sensor. Its behind the EVAP canister purge solenoid. One time my vacuum line fell off of my MAP sensor and the car was 'always' building boost and when driving about 50mph it was at 3500rpm. Turns out the vacuum line fell off of the MAP sensor nipple and all I had to do was plug that back in and the car ran fine.

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[CNorell145]

Sounds like a metal on metal knocking.

[tomtom123]

That's probably not good. As in.. Very bad.
2M USB 2.0 Endoscope Waterproof Inspection Camera Borescope 300000 pixels by Hittime http://www.amazon.com/dp/B00ELB71HY/..._bz8Gtb1MZ1A49
Might think about investing in that and checking pistons out. Or find a way to check if you have a rod knocking

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[Scottydoggs]

post a vid of said knocking if you can, in park bring the rpm's up to 2500 rmp's, then let the throttle drop back to idle.