Thread: Egr tube ??

99 gtp, n* setup, cam, zzp canned tune, rebuilt motor with 30k

i got a theory I wanted to run by the forum

im getting an occasional po507 (high idle) and an occasional fluttering of rpm on a part cruise throttle above 45-50 mph. The cel comes on usually after driving and at idle.

cars idles around a 900-1000 at park and around 750 in drive

i put on new vac lines about 3k ago/month I get a shakey needle from 14-15 bars at idle sometimes drops to 13.

i put a hose up to the ear and the only hear a hiss under the throttle body and the egr tube at the egr housing. When I spray around there I don't get a increase in idle so much but I can see it sucking in the spray from the egr tube at the egr housing. Egr tubes are new but were installed by po.

so I was thinking my egr tube to the throttle body could have a leak, BUT wouldn't that cause a leak only when the egr is open? The car has always idle around 900-1000 rpm, but after driving it and idling I have seen it 1100-12000 rpm.

thanks

any open hole in the system will suck in air into the intake that'll be unmetered.

Yeah i just reread the original post, duh

Just put zzp egr blockoff plates on and get rid of that silly thing. Then you can use the egr plug to log wideband fuel ratio!

Check your N* cables and bracket, often enough I see them binding or not quite adjusted properly to not put pressure on the throttle plate.

As for the tube, pull it and look. It's two 13mm's.

Thanks for the replies. I did pull the egr tube. It was half my problem, still have a leak at the throttle body somewhere. My fuel trims are extremely rich as well, never leaving the negatives, so maybe I am leaking on the exhaust side as well. The po507 is gone though!

I got a nic cam installed from the po. Has anyone heard of these cams having rough idles? My idle is still around 900-1k in park.

Well egr is gone and still the idle is no better. I must still have a vacuum leak. I was told 15" was a good reading at idle with the cam but I am still sure there is leak. I finally broke down for the aeroforce at its showing 11-12" cold and 13.5-15" warm. Idle is down to 900-1000 and no more code507. Would my can tune limit my idle from going lower? I check my throttle cables and tps values which checked out.

for you northstar users out there..... What gaskets do I need for the tb?

And is oem sc gasket still preferred? I got zzp gasket on now and I don't think I will be able to reuse it.