jon88se

Ok guys...I haven't posted in a long while but I think you guys can help me...the lean/rich screw by the AFM has to be at full lean for my car to idle well and I know it didn't used to be that way one my first motor (couple years ago). Anyway, the car smells a bit at idle (obviously rich) and when the car is at operating temps and I pull the plug out of the boost sensor nothing happens. Should it change the idle? When I pull the vacuum line out of the port by the ACV (which is blocked off) the car idles up which makes sense since that would be a vacuum leak. Idle is pretty smooth but sometimes inconsistent. I have another TB to put in that has the mod already done. Is my boost sensor shot, can it be fixed if so and if not how much is a new one? Also, when I do the TB mod install, what else should I play around with/open/clean around there? I hear removing the BAC = perfect idle and I know I'm goin under the upper intake manifold one o these days to put in the other RB block off for the EGR. Please let me know...the car makes great power and only has the 3800 hesitation when the motor is cold. Any thoughts on gettin my car perfect?


88' NA
-K&N, APEX'i dual dunk, 2.5 inch downpipe/2.5 inch cat, unorthodox crank pulley, Racing Beat 11 Lb flywheel, centerforce dual friction clutch, No ACV or airpump, soon TB mod.
-Ground control coilover conversion w/ Eibach 2.5 inch race springs, KYB struts/shocks, energy suspension bushings all 'round, Tein upper pillow-ball mounts, Greddy front strut brace, Cusco rear strut brace, Turbo II sway bars, 17 inch ADR stage II w/ 215/45/WR17 FR, 235/45/WR17 RR sumitomo HTRZ II's.
-'91 nose and tail lights, D-speed clear signals all 'round, Mazda wing (sport model '87), mazdaspeed front spoiler w/ R-Magic side skirts all waiting

jon88se

please help me out guys, I know a lot of you know the answers...the car should be apart this weekend so with your help I can get things done then...

Keith

OK, the only thing the ECU pays attention to at idle is that darn rich/lean screw. If you want to check your boost sensor, meter the Brown/Red stripe wire to ground. At idle, it should read Less than 2 volts. If you pull off the hose, it should jump to about 4 volts. If it does all this, it is fine. If you cannot get the setting on the screw away from max lean, you either have a leaking injector, larger than stock injectors (on the primaries), or a fried ECU.

BAC removal = perfect idle??? Yes, if you don't have air conditioning, you never travel with the lights on, you never turn on the heating system blower, you don't have a high-power stereo, you never turn on the small electric fan (or an aftermarket one, if you have it), and your battery never gets weak. Otherwise, you will have to idle it way up to keep it from stalling (any of the above will cause a severe drop in idle and/or stall without the BAC - it does have a purpose, you know).

Anyway, some info to play with. Have fun!

Irv, Keith's dad