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egr codes, and startup problems

718 Views 1 Reply 2 Participants Last post by  meangreen92
I just put in a 347 stroker, and the idle fluctuates from 0-1500rpm when cold and I have to keep it alive till it warms up, then it stays steady at 750rpm or so till I hit the gas or try to drive it. then its back to the same thing. I scanned the ecu and it gives me 31, 33.

I don’t have the tube from the h-pipe to the rubber smog hose (right by the passenger side header) connected snug to the h-pipe. Will that cause a problem? Also it starts up when it’s cold but if I shut it down and try to start it again it will not fire up.

thanks.
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It's possible that the absence of secondary air to the cat area might affect the EGR operation or detection, but I dont know. My car came with what looks like garden hose (only about 10-12 inches) connecting the H-pipe to the secondary air system down underneath. I'd try hooking it up just to see.
One test you can try, is with the car idling, remove and cap the vacuum line(a line in that particular vacuum circuit could be bad too) from the EGR valve itself. Attach a length of vacuum hose to the valve, and give it a suck (do this while the engine is idling as normally as you can get it). The motor should stumble. Then do a KOEO and Continuous Memory scan, and see if it throws a 34 out of CM - it should. That will tell you that the EGR Valve Position sensor is working.
You've double and triple checked your electrical connections?
The hot no start sounds like a TFI, but I've seen other threads about hot no starts on fresh builds.
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