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View Full Version : SR is misfiring and can't locate?


sr20time
09-18-2011, 06:57 PM
Ok, so here's the problem. car sat for about 6 months while i was working, got home and started just fine. drove it once, bov vacuum line was melted so i fixed that and it was good again. drove it the next day without issues.

the next morning it started up and was running super choppy, misfiring, and would barely drive. it sounds/feels like its misfiring but im not so sure. right now its running a garrett 2560r turbo, stock injectors, walbro 255, hks cams, stock ecu and no boost controller (10psi). i checked the coil packs and all were sparking so i know all 4 have spark. if i pull the plugs (which are brand new) they all have a little bit of fuel on the ends so i know the injectors are firing, if its idling and i unplug the maf nothing changes and the car wont rev above 3k it jumps/backfires and dies. i inspected and cleaned the maf and it wasnt very dirty. anyone have any other ideas? also checked compression and numbers were 150, 140, 135, 140. cylinder 3 is a little low but not low enough to cause this....

ShadowMan
09-18-2011, 09:00 PM
Check for boost leaks. Like you said, your car sat for 6 months. Thats a lot of time for rubber to rot/crack/deteriorate. I know everyone always check for boost leaks but do more than make sure your couplers are tight, make sure they are all in servicable condition. Look them over good. 6 months is also plenty of time for critters to get up in there chew the shit outta your wires and what not as well. I know you said your coils are getting spark, but use a multimeter to make sure their getting the power they are supposed to. Just because there is spark does not necessarily mean its a powerful spark. Also, there shouldn't be fuel on your plugs, so check the o-rings on your injectors to make sure they haven't rotted as well. It would just be a good idea to go over all your rubber hoses/lines/o-rings/seals to make sure they are good. This problem could be a hint to future, more catastrophic failure. I would also check to see if you melted any of your wiring like you did your bov vacuum line. Sometimes shit will get way too hot as you drive but since their was already a good current in the wires it was fine, that is until you shut the car off and everything cooled down and now it might be having a hard time trying to push the proper amount of voltage to what ever it is that may be the culprit because something became partially melted. Thats all i can think of for now. Let me know what you find.

sr20time
09-18-2011, 09:36 PM
Found the problem.. pulled the maf off cleaned it and... it fired up. strangest things but such a simple fix after going through what we did.. thanks ShadowMan. in other words... im dumb ha.

ShadowMan
09-18-2011, 10:59 PM
No problem, glad it was a simple fix.