bizkit
bonofied SyTy junkie
Well I've been struggling with a misfire on my Ty for a couple weeks now and can't figure it out. It's not a dead miss and is erratic and is worse when the Ty is warm, and does not go away at higher rpm's though you don't notice any driveablility problems on the highway.
New plugs, wires, cap, rotor, tried two different HEI modules, 3 different coils, and purged the injectors with Wynns VIC injector/top end cleaner. All the plugs I pulled out looked exactly the same, a nice brown color. What is really weird is that it gets worse when I put on a MSD blaster coil. So does that mean the MSD puts out less energy than the stock coil and makes the miss worse, or does it put out more energy and arc out somewhere that much more to make the miss worse? On tunerpro the vaccuum is at 17 - 18 Hg at idle, and you can watch the O2 mv go rich whenever you hear it missfire.
Im grabbing at straws now. Tomorrow night I will try swapping in the MAP sensor from my S-10, and try to track down which plug is misfiring using a timing light by looking for an erratic light signal.
From inside the cab all you notice is that at idle (redlights etc) the truck wants to die when going into gear or sitting still for awhile. Under load for example a boost launch, it's hard to notice anything is wrong. You notice it the most when the truck is idling and you get out and lean down to listen to the exhaust at the tail pipe.
Any other ideas on what to check next? I don't want to let this stop me from going to Nats, but I'm just not sure if I should go that far with a truck that's not 100%. The best thing would be to put it on an oscilloscope at a dealership to check all the plug wires/injectors at once and graph it all out, but there aren't any in town anymore.
What do you guys think?
I've also played with the fuel pressure, changing it from 30 to 60 psi and it made no difference. I've had it and it is right now set at 50 psi.
New plugs, wires, cap, rotor, tried two different HEI modules, 3 different coils, and purged the injectors with Wynns VIC injector/top end cleaner. All the plugs I pulled out looked exactly the same, a nice brown color. What is really weird is that it gets worse when I put on a MSD blaster coil. So does that mean the MSD puts out less energy than the stock coil and makes the miss worse, or does it put out more energy and arc out somewhere that much more to make the miss worse? On tunerpro the vaccuum is at 17 - 18 Hg at idle, and you can watch the O2 mv go rich whenever you hear it missfire.
Im grabbing at straws now. Tomorrow night I will try swapping in the MAP sensor from my S-10, and try to track down which plug is misfiring using a timing light by looking for an erratic light signal.
From inside the cab all you notice is that at idle (redlights etc) the truck wants to die when going into gear or sitting still for awhile. Under load for example a boost launch, it's hard to notice anything is wrong. You notice it the most when the truck is idling and you get out and lean down to listen to the exhaust at the tail pipe.
Any other ideas on what to check next? I don't want to let this stop me from going to Nats, but I'm just not sure if I should go that far with a truck that's not 100%. The best thing would be to put it on an oscilloscope at a dealership to check all the plug wires/injectors at once and graph it all out, but there aren't any in town anymore.
What do you guys think?
I've also played with the fuel pressure, changing it from 30 to 60 psi and it made no difference. I've had it and it is right now set at 50 psi.
