Popping, spuddering, and sometimes stalling @ WOT
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Popping, spuddering, and sometimes stalling @ WOT
I just got the car going again, and its been driving just fine. but just this past weekend it started to sputter and backfire and sometimes even stall under WOT above 3.5k. now it dosnt do it all the time, sometimes i can row through the gears with no problem. other times it will do it in first gear.
My thought is the fuel pump is diying. but its got 43.5 psi running with the vac line disconected. but, on the other hand, when the sputtering happends my wideband shows it leans out pretty baddly. tommarow when i get outta work ill try to see if i can rig up the pressure gage somehow and give her the go and see if im loosing fuel pressure.
the car is a 95z M6 383 LT1 with #30 svo red tops, xfi 280 cam, le3 heads, le intake, SLP intake, ebay LPP knockoffs, with a sock i pipe and a pos choke master muffler. Fuel system is all stock except for a new fuel filter and injectors. stock 105k opti with a new cap and rotor.
am i on the right track or am i missing something?
Thanks alot!
My thought is the fuel pump is diying. but its got 43.5 psi running with the vac line disconected. but, on the other hand, when the sputtering happends my wideband shows it leans out pretty baddly. tommarow when i get outta work ill try to see if i can rig up the pressure gage somehow and give her the go and see if im loosing fuel pressure.
the car is a 95z M6 383 LT1 with #30 svo red tops, xfi 280 cam, le3 heads, le intake, SLP intake, ebay LPP knockoffs, with a sock i pipe and a pos choke master muffler. Fuel system is all stock except for a new fuel filter and injectors. stock 105k opti with a new cap and rotor.
am i on the right track or am i missing something?
Thanks alot!
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Ill do just that! Just hope the hose on my gauge is long enough.
Also I'm 98% sure it the stock original fuel pump with 106k on it. About the right time for it to start dying right?
Also I'm 98% sure it the stock original fuel pump with 106k on it. About the right time for it to start dying right?
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Thanks for the responses guys!
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well fuel pressure seemed ok, never really droped off. i thought that was it when i had the vac line connected as it would go down to about 35-38 psi under WOT. so i disconnected the vac line and it held 43.5 mostly, i think the lowest i seen it get was 41ish. but on the wideband it still did the same thing, leaned out and fell on its face.
Any reason the PCM would cut fuel? ideas please.
i checked the plug wires and all seemed fine. no cracks or burnt marks anywhere. also checked the spark from the coil to ground and seemed fine. was mostly blue with some yellow in it depending how long the arc was.
Thanks guys
Any reason the PCM would cut fuel? ideas please.
i checked the plug wires and all seemed fine. no cracks or burnt marks anywhere. also checked the spark from the coil to ground and seemed fine. was mostly blue with some yellow in it depending how long the arc was.
Thanks guys
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just recently. its been running for about 3-3.5 months now. i got the car with a spun bearing, but i got it from a friend and he says its never done that before. i rode in it about a month before it spun the bearing and everything was good then.
i deced to check for vac leaks and pull the maf for a good cleaning. i know i never cleaned it and it did not look like it had been cleaned recently. i took it for a quick spin and going by the a\f guage its running .5 to a full point richer. i only did a couple pulls and all seemed well. IDK maybe it was diry?
also i have a descreened maf that came with an lt1 i bought for it orginaly, should i try it if it continues tommarow?
Thanks for the help!
i deced to check for vac leaks and pull the maf for a good cleaning. i know i never cleaned it and it did not look like it had been cleaned recently. i took it for a quick spin and going by the a\f guage its running .5 to a full point richer. i only did a couple pulls and all seemed well. IDK maybe it was diry?
also i have a descreened maf that came with an lt1 i bought for it orginaly, should i try it if it continues tommarow?
Thanks for the help!
Last edited by Fazz73jr; 11-17-2010 at 01:09 PM.
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so since i had cleaned the maf it had been running good. i was confident enough to run it at the track tonight. it did well for the shitty track conditions, my mph was up but ETs where not. ran a best of 8.4 @ 88mph in the 1/8th. ran great there no problems.
a couple blocks away from my house on the way home i see this RSX thats been talking ****. i get next to him for some fun, i roll out 1st gear to go from a roll @ about 15-20mph and the SOB started doing it again!! just leaned out and fell on its face like a fuel cut. i push the clutch in and the rpms drop, then pop revs up on its own to about 1500 the shoot back down and pop. WTF is going on?!
I hate to jump on the bandwagon but could it be the opty? its got about 105k on it, but has a new cap and rotor. also thinking maybe somehow it got a bad flash? theres been at least 2 time i can recall that it would go into DFCO going down hill for a good 20-25 sec and not come out. Id hit the gas and noting, i would push the clutch in an it would die. i would just trun the key off and restart and it would be ok again. IDK what to think now...
HELP
a couple blocks away from my house on the way home i see this RSX thats been talking ****. i get next to him for some fun, i roll out 1st gear to go from a roll @ about 15-20mph and the SOB started doing it again!! just leaned out and fell on its face like a fuel cut. i push the clutch in and the rpms drop, then pop revs up on its own to about 1500 the shoot back down and pop. WTF is going on?!
I hate to jump on the bandwagon but could it be the opty? its got about 105k on it, but has a new cap and rotor. also thinking maybe somehow it got a bad flash? theres been at least 2 time i can recall that it would go into DFCO going down hill for a good 20-25 sec and not come out. Id hit the gas and noting, i would push the clutch in an it would die. i would just trun the key off and restart and it would be ok again. IDK what to think now...
HELP
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Randomly cutting out and going lean tells me the injectors are losing signal to fire which very well could be the opti... or crank position sensor but.... eh opti
Since you said cleaning the maf helped try unplugging it and driving it around albeit with a cel you can eliminate that from being the culprit if it continues to act up
Since you said cleaning the maf helped try unplugging it and driving it around albeit with a cel you can eliminate that from being the culprit if it continues to act up
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I'm noticing its happening more when I roll into the throttle before it goes WOT. Could it be the TPS?
I have not been able to log it as my laptop is down for the count.
Any help/suggestions are welcomed! Thanks!
I have not been able to log it as my laptop is down for the count.
Any help/suggestions are welcomed! Thanks!
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I hooked a gage to mine it would say 39 psi at wot it would drop to 31 psi win i pulled vacum line off it went to 45?? Mine to out to be fuel pressure regulater? So it could be that to!!
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I tried the TPS i had on a spare motor that was runing fine and it made no differacne. thinking maybe ICM or my o2's.... idk
Thanks for the responces guys!! keep em coming!