misfire on all cylinders! no DTC
04-30-2015, 08:31 PM
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misfire on all cylinders! no DTC Ok this may be the wrong place to post this as I am new to the site. I have a 99 SS m6. Mods are.
Lid
ported T.b
bbk ssi Intake
hooker longtubes and 3 in ory.
it literally happened over Night ran good one day and the next morning I fired it up and the service vehicle light was on and the air bag light was flashin. Shut it off and started it back up. And they were off. Got about a mile from the house and noticed it wasnt running right. Took it up and had the codes read. It had a code for tps low Input voltage. and two more codes abs codes for the tps sensor telling the *** to be turned off and one more i can't remember at this time but I will post it after I type this up...... I replaced the t.p.s sensor thinking that was it no change... long story short I have replaced plugs, wires, coils, fuel pressure, checked for five volt reference at the t.p.s and a Smooth sweep I checked the 02's and m.a.f. I bought a crappy bluetooth obd scanner from advance that reads live data. Every thing seems fine and within parameters. Took it to a friend of.my dad's with a snap on solus scanner and it's randomly misfiring on all cylinders under load..... I'm baffled I have looked all over the website for a fix and can't find one. Any thoughts? I'm baffled and about to pull my hair out..
Lid
ported T.b
bbk ssi Intake
hooker longtubes and 3 in ory.
it literally happened over Night ran good one day and the next morning I fired it up and the service vehicle light was on and the air bag light was flashin. Shut it off and started it back up. And they were off. Got about a mile from the house and noticed it wasnt running right. Took it up and had the codes read. It had a code for tps low Input voltage. and two more codes abs codes for the tps sensor telling the *** to be turned off and one more i can't remember at this time but I will post it after I type this up...... I replaced the t.p.s sensor thinking that was it no change... long story short I have replaced plugs, wires, coils, fuel pressure, checked for five volt reference at the t.p.s and a Smooth sweep I checked the 02's and m.a.f. I bought a crappy bluetooth obd scanner from advance that reads live data. Every thing seems fine and within parameters. Took it to a friend of.my dad's with a snap on solus scanner and it's randomly misfiring on all cylinders under load..... I'm baffled I have looked all over the website for a fix and can't find one. Any thoughts? I'm baffled and about to pull my hair out..
04-30-2015, 08:57 PM
#3
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What sort of fuel pressure are you getting at the rail? open the throttle a bit and check to see if the fuel pressure stays constant or if it starts to dip once you open the throttle. You should be at around 58-60 lbs when running.
04-30-2015, 09:01 PM
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It's at 58 Psi at idle. And when you blip the throttle it drops to 54#'s for a Second and come right back. I forgot to mention I also ran a compression test and all cylinders were at 150
