stevenjohnson

nice 88 conv. great compression. problem is runs terrible rich at idle and at speed... have ANOTHER 88 conv that runs great... swap out EVERYTHING... air flow meter. throt pos sensor, water temp switch, map sensor, variable resistor, aux air valve, injectors... nothing makes any dif . didn't even bother to switch parts back as second car STILL ran fine. fuel press reg seemed weird so drilled it out... car THEN runs well... so i buy a BEW fuel press reg...same prob... chk fuel press ... drilled one runs 19 psi and car runs well... new one 34 and same problem... something is telling this car to be rich and the low fuel press just offsets the curve enough to mask the problem... what else is there ?

also have a fresh bruce turrentine rebuilt 13b w/ flywheel, still in shrinkwrap w/ 1 yr warrantee for sale...950 plus shipping...sitting only 30 days since rebuild.

please contact me direct w/ advice or questions...
steve@stmartin.com

thanks

gotdatfiyah

just un hook the exhaust from the y pipe back and see what it does

stevenjohnson

did that........no change

SureShot

Leaking injector(s) maybe?
How fast does the fuel pressure bleed down after shut off?

stevenjohnson

with drilled ou regulator at 19 psi, bleed down is immediate...cranks a bit to start but no big deal... with new reg, bleed down is zero.... injectors were out, cleaned and tested perfect... exchanged w/ ANOTHER set of inj anyway...same problem.... SOMTHING is telling the ecu that the pusle width needs to be long when it doesn't... yet all the sensors that control that that i am aware of have been changed out...and when any sensor is disconnected motor reacts instantly so harness to ecu is good... this thing is roughly 30 % rich ...why ?

ERAUMAZDA

Dude check your spark plugs and ignitors

stevenjohnson

plugs are /were new ...why would car run fine at 19 and bad at 34 psi...you are suggesting that the igniters will work JUST well enough to do that ? no way... fuel curve at full throt at 19 psi the same as part throt at 34...car runs fine at full throt at 19 so igniters good enough to run that mixture.... no...this is not a weak ignition deal...it's a too much fuel deal...