I've had a tough time tracking down a high BLM problem for a long time on my 87 GN, and a knock problem. I hoped they were related, and if I fixed the BLM problem, the knock problem would be solved also. With a combination of new vac lines, new PCV valve and grommet, fixing cracked headers, and installing a solid MAF pipe (in place of the old stock hose) I have the BLM problem fixed, but still get knock at 12 psi (autometer gauge). At about 55-60 MPH in second gear, the O2s are 820 or so, and the MAF shows about 200, then I have to let off because of detonation. I'm suspecting a bad MAF, but I wanted to fix other obvious stuff first (see the list above). All that being said, By the time you reach 10-12psi should the MAF be maxed out?
Everything is stock except for a K&N, Walboro 307 hotwired, and adj. FPR, even the chip. I figured if I couldn't get it to run a good baseline on the stock (emmission) chip, then I shouldn't go changing other stuff until I get this sorted out. Any suggestions would be appreciated.
Larry