canadianVRss Posted July 26, 2013 Report Share Posted July 26, 2013 hello everyone, over the last few days my truck has started acting up. at first start up it's fine, no sputtering at all. once it starts to get warmed up it will sputter. it gets worse and worse as it gets to temp, and if it gets hot when sitting in traffic its very very noticable. the sputtering is most prominant when at idle all the way up to 2000rpm, 2000rpm and up isnt a problem. at first i though it was a burned plug wire (i have OBX LT's and they tend to fry wires do to close header proximity on the drivers side). i pulled the two drivers side plug wires and they were cooked. i pulled and replaced them with custom made wires that clear perfectly without touching the headers (no zipties either, hit me up if interested). while i was at it i checked all the plugs to see if any were broken or cracked. ALL were fine. so unless i've got a broken coil (which i doubt) i should have spark to all 8. Next i checked air. filter is clean, maf sensor is not applicable do to me running a SD tune and TB is clean. spark good, air good. that leaves me with fuel, all the injector connections are tight so im guessing fuel pump? but wouldnt that mean 2000rpm and up would sputter worse do to needing more fuel and not having it delivered? or possibly a clogged injector? whats the most likely problem? i will attach a fuel pressure gauge tommorow and see what i get when sputtering. im attaching a hpt log of sputtering at idle and sputtering while driving, so if anyone has hpt they can take a look. in the log everytime you see the idle jump to or above 800+ rpm is a direct correlation to a sputter. im hoping its nothing engine mechanical, because i really dont feel like pulling the engine and rebuilding.... thanks for reading. sputtering at idle.hpl sputtering.hpl Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted July 26, 2013 Report Share Posted July 26, 2013 Normally if it were a fuel pump you would have issues with the truck dying from time to time. My first thing I would do is get some sea foama nd put some in the gas tank and the brake vacuum line. It will remove any moisture in the fuel, stabilize it and clean the fuel system and carbon in the motor. It could be a coil but you would more than likely have a dummy light on for that. Quote Link to comment Share on other sites More sharing options...
Sneakystiffler21 Posted July 26, 2013 Report Share Posted July 26, 2013 (edited) I would think it having issues after it's come up to temp a sensor is having issues but not making the dummer light come on yet. O2 sensor or one maybe knock sensor... Hard to tell without hooking up to a computer. Try to seafoam first. Edited July 26, 2013 by Sneakystiffler21 (see edit history) Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted July 27, 2013 Author Report Share Posted July 27, 2013 Well things got worse today, the sputtering got so bad it'll do it all the way up to 4000rpm and it'll shake the whole truck! Especially if I sit at a red light and it gets really warm. When I leave from the light it'll feel like 1 or more cylinders wont fire and it'll surge as it begins to fire intermittently. Sometimes it'll shake really bad and then all of a sudden it'll run perfect and pull hard. Because its so intermittent I'm thinking electrical, I rechecked all of my connectors and the splices I made for the uscar type injectors. It all looked good. When it shakes and sputters it feels like a 6oz weight is on my crank balancer and shaking the piss out of everything. So weird. Oil pressure is good. I pulled the valve cover and all the valve train is also good. Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted July 27, 2013 Report Share Posted July 27, 2013 Could be a bad cat... Hard to say without actually having the truck in person. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted July 27, 2013 Report Share Posted July 27, 2013 The truck hasn't thrown any codes?? Quote Link to comment Share on other sites More sharing options...
Muggs Posted July 27, 2013 Report Share Posted July 27, 2013 Did you find anything out? Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted July 27, 2013 Author Report Share Posted July 27, 2013 Blown: no cats Fireman: no codes Muggs: nothing yet So stumped on this one boys. It's got to be something stupid and simple I missed somewhere. Zippy is going to send me a tune to ignore the front o2s to see if they're shot. Quote Link to comment Share on other sites More sharing options...
Fireman31 Posted July 28, 2013 Report Share Posted July 28, 2013 Have you checked fuel pressure at all?? Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted July 28, 2013 Author Report Share Posted July 28, 2013 (edited) Have you checked fuel pressure at all??I am extremely suspect of the fuel pump. I haven't checked fuel pressure yet, but the pump does prime at start up (can hear it buzz). I've seen pumps do some weird things. I'm iffy on pulling the trigger on a $200 fuel pressure gauge and set up, but its lookin like I might have too to completely rule out the pump malfunctioning or not. Edit* my wide band reads 11.5 at wot from a launch. Even while its shaking. Edited July 28, 2013 by canadianVRss (see edit history) Quote Link to comment Share on other sites More sharing options...
Blown 346 Posted July 28, 2013 Report Share Posted July 28, 2013 I would first test the voltage of the pump itself at prime and while its running. With having no codes or lights on, it rules out half the issues it can be. I would look over all grounds and check and make sure they are tight and clean. One loose ground cable or one that isnt making a great connection can have a effect on driveability of the truck as well. Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted July 28, 2013 Author Report Share Posted July 28, 2013 I would look over all grounds and check and make sure they are tight and clean. Excellent idea. Totally didn't think of that. Quote Link to comment Share on other sites More sharing options...
2003_SuperSport Posted July 28, 2013 Report Share Posted July 28, 2013 Might want to not do anymore WOT pulls in case it is a pump problem and without a pressure gauge it may be hard to tell cause if it drops to far below recommended lbs you might go to lean and fry a piston... Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted August 1, 2013 Author Report Share Posted August 1, 2013 Grounds are good. Got a new symptom. Massive cold start backfires. It sounds like a firecracker going off in a sealed coffee can. Quote Link to comment Share on other sites More sharing options...
canadianVRss Posted August 2, 2013 Author Report Share Posted August 2, 2013 Well I think I got it figured. I looked over everything... Again, and gave the plugs a really good look this time. I was running autolite 103s, which are black (everything south of the threads, including the ground strap). So they look brand new. I never would've noticed until I looked at the ground strap extra close. There was a thin layer of, I'm not sure really. It was a hard coating of something red. Kind of like the natural colour of potery a dark dull red. Anyone good at reading plugs that could know what it is? Anyway new plugs (back to ngk so I can actually see any carbon build up) and she's banging like a champ again... I feel so stupid lol damn black spark plugs. Quote Link to comment Share on other sites More sharing options...
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