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Forum nameTurbo/Nitrous Tech
Topic subjectMIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=64495
64495, MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by DSMRoadster, Feb-02-04 03:47 PM
Sometimes when I boost out 1st straight to 12-15psi my car would immediately start to misfire right after. Today I disconnected the battery, changed the plugs and waited 15 min. Reconnected the battery start the car and car starts sputtering. Digital a/f read 1.XXX at idle and under load. Disconnected the battery, wait 15min, took out the fuse for inline (disabling it), reconnect battery and start and car idles fine. Put fuse for inline back in and car starts sputtering again. Took fuse out and car conitnues to sputter and digital reads 1.XXX at idle and load. Disconneted the battery again, wait 15 reconnect with inline pump disable and car idles fine. Drive it with inline pump disable for 7-10 miles and car drives fine and af reads fine. 4 hours later, started car and it automatcially shuts itself off. This happens 6-7 times. I put the fuse for the inline pump back in and start the car. Car idles and drives almost fine. Only problem is when I break real hard, the rpm would drop quickly and almost shuts the car off. So what gives?
64498, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by XtremeRS, Feb-02-04 03:56 PM
What are your fuel pressures when this is happening?
64500, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by widebodied, Feb-02-04 04:12 PM
im throwing this out in the air but it almost sounds like a battery or altenator problem. some kinda voltage drop. i dunno, just check and see what your alt is putting out and ur bat level

DWAYNE H
1996 eclipse
under construction widebody eclipse, targa top, 19inch rollers, big brakes, 10 point custom cage, frank 2.4 hrc s20g turbo, custom marble paint job

2000 Yamaha R-1, 165rwhp 117 ftlbs tq

ALMOST THERE...... MUWHAHAHAHAHAHA
Originally posted by Thunderous_Talon
a man could build a thousand bridges, and suck one cock. he'll forever be known as a cocksucker.
64501, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by DSMRoadster, Feb-02-04 04:13 PM
fp is normal. and alternator and battery is fine too.
64515, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by ner947, Feb-03-04 05:19 AM
how old is your oxygen sensor?
64530, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by JasonESi_T, Feb-03-04 07:52 AM
Bad wire or plugs. JMO
64599, RE: MIsfire, sfmu, 30ibs, 12psi and inline fuel pump
Posted by DSMRoadster, Feb-03-04 05:29 PM
I just changed o2 sensor and I tested wires and coil pack with new plugs. Hey Nate, explain why you widen the whole on the resistor again? I'm thinking because of those straight 15psi boost, that for that moment my fuel is extremely rich and dumping so much fuel into the engine that it causes misfires. Maybe if my resistor is bigger then, the sfmu wouldn't dump so much for it long enough to flood the engine.