Warthog32695 Posted September 13, 2013 Report Share Posted September 13, 2013 Hey guys, i am in need of some help form those of you with knowlage of the GM 3.1 SFI V6 engine. Well i have a 94 vert, i love it but its been acting so strange latey i cant figure it out,. It really frustrates me snice this is what i do for a living is working on cars. its hard to explain its like its bucking almost? engine RPM will just drop ramdomly for a second and shoot back up i am forced to use her as my commuter for the time being snice i can no longer afford to fill my Truck up every day, and my escort is complety undrivable. If somone could help me figure it out id be super great full snice i really dont wanna break down on my way to collage or work. well heres a video so you can see exatly whats going on -Kyle D P.S. if im in the wrong section please let me know and ill fix it Quote Link to comment Share on other sites More sharing options...
Pontiac6KSTEAWD Posted September 13, 2013 Report Share Posted September 13, 2013 It being a 94, which makes it have the 3x00 engine. Otherwise I would have said to check your injectors.. But since this is a 3x00 engine, 3 things come to mind. Fuel Filter, Ignition Control Module, or, Crank Position Sensor. In that order also.... Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 13, 2013 Report Share Posted September 13, 2013 What do your electronics do when this occurs? Do the lights dim? Did this start doing it all the sudden or after working on it? What have you already checked or replaced? Is the car properly maintained? How often does it occur? More information will be required. Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 13, 2013 Report Share Posted September 13, 2013 Whats the mileage Hey guys, i am in need of some help form those of you with knowlage of the GM 3.1 SFI V6 engine.Well i have a 94 vert, i love it but its been acting so strange latey i cant figure it out,. It really frustrates me snice this is what i do for a living is working on cars. its hard to explain its like its bucking almost? engine RPM will just drop ramdomly for a second and shoot back up i am forced to use her as my commuter for the time being snice i can no longer afford to fill my Truck up every day, and my escort is complety undrivable. If somone could help me figure it out id be super great full snice i really dont wanna break down on my way to collage or work. well heres a video so you can see exatly whats going on -Kyle D P.S. if im in the wrong section please let me know and ill fix it Quote Link to comment Share on other sites More sharing options...
Warthog32695 Posted September 13, 2013 Author Report Share Posted September 13, 2013 (edited) The lights do not dim, somtimes the speedo goes crazy. The car is very well maintained. And it just started one day. Already replace the fuel filter about 1,000 miles ago when it started, the car now has roughly 121k on her happens every 10 minuites or so seems to begetting worse Edited September 13, 2013 by Warthog32695 Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 13, 2013 Report Share Posted September 13, 2013 Check engine harness mine did the same thing, short in pcm fuse box wiring The lights do not dim, somtimes the speedo goes crazy. The car is very well maintained. And it just started one day. Already replace the fuel filter about 1,000 miles ago when it started, the car now has roughly 121k on her happens every 10 minuites or so seems to begetting worse Quote Link to comment Share on other sites More sharing options...
Warthog32695 Posted September 14, 2013 Author Report Share Posted September 14, 2013 well the envitable happened, on my way to school she died. had to get towed to Work and find a car to use to get to school. was pretty much the same thing that its been doing, then i was i couldnt even go with out it acting up, then she stalled out and that was it, normally if it does it will start back up and ill be on my way, this case nope just cranks kinda sad.. Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 14, 2013 Report Share Posted September 14, 2013 Harness b good time to convert to obd2 well the envitable happened, on my way to school she died. had to get towed to Work and find a car to use to get to school. was pretty much the same thing that its been doing, then i was i couldnt even go with out it acting up, then she stalled out and that was it, normally if it does it will start back up and ill be on my way, this case nope just crankskinda sad.. Quote Link to comment Share on other sites More sharing options...
Warthog32695 Posted September 14, 2013 Author Report Share Posted September 14, 2013 convert to OBDII? i dont think its even worth it. i like the simplisty in the car, i pefer older systems anyways. but this could all be realated to the wireing harness? Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 14, 2013 Report Share Posted September 14, 2013 My monte did the same thing how would it b tedious to swap to obd2? Pcm a few sensors and a harness and you need a harness anyway. I like availability of the scanners myself convert to OBDII? i dont think its even worth it. i like the simplisty in the car, i pefer older systems anyways. but this could all be realated to the wireing harness? Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 14, 2013 Report Share Posted September 14, 2013 You mentioned a "bucking" sensation. Like a miss fire? Its been a while since I've experienced one, but I believe that would cause your rpm`s to act erratically. Coils? spark plugs? plug wires? Could also be faulty fuel pump or a bad injector. Unless you are planning an engine swap OBD swapping really doesn't make a lot of since. I`d focus on repairs vs mods. What has been tested and ruled out? Quote Link to comment Share on other sites More sharing options...
l67ss Posted September 14, 2013 Report Share Posted September 14, 2013 He mentioned erattic speedo leads back to the harness You mentioned a "bucking" sensation. Like a miss fire? Its been a while since I've experienced one, but I believe that would cause your rpm`s to act erratically. Coils? spark plugs? plug wires? Could also be faulty fuel pump or a bad injector. Unless you are planning an engine swap OBD swapping really doesn't make a lot of since. I`d focus on repairs vs mods. What has been tested and ruled out? Quote Link to comment Share on other sites More sharing options...
True Blue Posted September 14, 2013 Report Share Posted September 14, 2013 My 1993 vert (3.4 liter) did the same thing last summer, and it was the throttle position sensor (TPS) going out. $300 later on July 4 while we were traveling in it solvd the problem. Honestly, if you can run by a junkyard and take your luck on pulling a TPS from another car, it might be cheaper to determine if that is the actual problem vs. something else fuel injection related. Hey guys, i am in need of some help form those of you with knowlage of the GM 3.1 SFI V6 engine.Well i have a 94 vert, i love it but its been acting so strange latey i cant figure it out,. It really frustrates me snice this is what i do for a living is working on cars. its hard to explain its like its bucking almost? engine RPM will just drop ramdomly for a second and shoot back up i am forced to use her as my commuter for the time being snice i can no longer afford to fill my Truck up every day, and my escort is complety undrivable. If somone could help me figure it out id be super great full snice i really dont wanna break down on my way to collage or work. well heres a video so you can see exatly whats going on -Kyle D P.S. if im in the wrong section please let me know and ill fix it Quote Link to comment Share on other sites More sharing options...
Warthog32695 Posted September 14, 2013 Author Report Share Posted September 14, 2013 from what i was able to tell it was the ingition coils, i wilgeled the wires and it fired up Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 14, 2013 Report Share Posted September 14, 2013 (edited) TPS from a yard would be fairly easy to find. Worth a try if you believe that's what it is, But a faulty TPS should have triggered a " check engine" on the cluster. But without knowing what has been tested its hard to give a firm diagnosis. So logically I`d start with the basics Air, Fuel, Spark. If everything that supplies these are functioning then you might have problems with the harness or elsewhere. Changing out the harness and PCM are pretty drastic considering one does not know where the fault is. Edited September 14, 2013 by rich_e777 Quote Link to comment Share on other sites More sharing options...
rich_e777 Posted September 14, 2013 Report Share Posted September 14, 2013 from what i was able to tell it was the ingition coils, i wilgeled the wires and it fired up Well there you go:thumbsup: Quote Link to comment Share on other sites More sharing options...
Warthog32695 Posted September 14, 2013 Author Report Share Posted September 14, 2013 fuel pump and filter is okay, ive tested. Car made a really bad smell in exuast, allways smelled like runing rich. Airlflow sensor seems okay, thats all ive really be able to do so far Quote Link to comment Share on other sites More sharing options...
Schurkey Posted September 14, 2013 Report Share Posted September 14, 2013 Now that you've got a hard failure, five minutes with a REAL scan tool will tell the tale. Quote Link to comment Share on other sites More sharing options...
OneBadCutt Posted September 16, 2013 Report Share Posted September 16, 2013 fuel pump and filter is okay, ive tested. Car made a really bad smell in exuast, allways smelled like runing rich. Airlflow sensor seems okay, thats all ive really be able to do so far Just had a sorta the same issue, can you test the fuel pressure on the 3.4 DOHC? If so what was it? Just because you can/can't hear I doesn't mean anything, I can't hear my brand new one and I could barely hear my old one. Just a thought. Quote Link to comment Share on other sites More sharing options...
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