F'n EGR....but its required.
82 B2000 beater. it will pass that EGR function test as I pulled line and idle cleared up. apply vacuum and it roughens. Its just the EGR raises a little at idle with almost no vacuum to it. Ill play with the EGR, it may have a little threaded pintle that I can lower, increasing the closed spring tension. The thermo valve may be stuck open too as it shoud be blocking the EGR vacuum under 122F coolant. but thats small potatoes as the test is done warm anyway. Thanks.