Surging idle, no codes.. I recently put on some aluminum L98 heads and got rid of the egr with a blockoff plate. I removed the egr solenoid and plugged the two lines at the TB and charcoal canister. My idle surges and is very erratic, sometimes it sounds like the car is going to die, and it did a couple times before I changed the o2 sensor.(once turning, once at a light)

 

Rezinn,

The EGR (or lack thereof) really shouldn't affect the idle unless the vacuum line that connected to it is left off and is leaking.

The EGR isn't even supposed to be open unless the engine is warmed (above 133°F at the CTS), at part throttle cruise (above 40MPH and less than 20% TPS), and is under a relatively light load (engine speed is relatively low compared to road speed).

You might eventually have detonation problems from lack of an EGR, but it shouldn't affect the idle one bit. As long as your block off plate is sealed well, there should be no problems caused by the EGR.

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Later,
Vader
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Justice and Freedom will Prevail

 

Thanks Vader, now Im troubleshooting the surging idle. No vacuum leaks. New spark plugs, o2 sensor. No codes. Idles high but good with MAF disconnected, but crappy with it connected. Relays and sensor are new, but sensor is remanufactured. No matter how I adjust the TPS and IAC the idle manages to fall below 1000 in park and starts to surge from 750-450ish, then revs up the 1500 and repeats. Im going to school in two days, and after spending a large part of the summer working on this car, I would have liked to take it. Unfortunately I have little time to work on it now, any ideas? Im going work on it tomorrow morning before I pack.

One more thing, I checked the fuel pressure today and it was at 50psi with the ignition on, so I backed off the screw in my afpr and bled off the pressure, then turned my lights on to reprime to fuel pump and the pressure went to about 50ish and fell very low very quickly. I haven't tested it at idle yet for lack of time, but Im guessing the pressure should not have fallen and should remain constant at idle. Correct?

What a day.