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View Full Version : engine pinging bad HELP



creeperxr7
12-17-2007, 12:19 AM
OK my engine at crusing speeds its fine but under slow acceleration it will start rattling like crazy but not if i let off a little. the idle has always been rough as hec since i rebuilt the engine. engine has 5000 miles on it. . the only mods i done are underdrive pulleys, 10% supercharger pulley, cold are intake, ported the manifolds alittle, magnaflow res, flowmaster mufflers and no cats......the original maf i replaced with one from a newer supercoupe with a bigger opening just kept same sensor...... and red injectors. i just want it running good at idle my hole car shakes and no not the motor mounts theyre new.... what would the camsensor do if not installed right maybe a little off.. or if u were a tooth off or 180' off would it run at all run like crap any info i would realy REALY apriciate it guys
:o

creeperxr7
12-17-2007, 01:03 AM
oh and scorpion roller rockers

David Neibert
12-17-2007, 01:03 AM
the original maf i replaced with one from a newer supercoupe with a bigger opening just kept same sensor......

This may be what's causing the problem.

David

creeperxr7
12-17-2007, 01:06 AM
so what should i do put the maf with the little opening. or put the new maf with sensor and all. thanks for the reply dave

Stupid Canuck
12-17-2007, 02:06 AM
Early model MAFs were set for 30# injectors and late models had 36#. At this point you may want to go for a C&L with the proper sampling tube.

You can go back to scratch with the cam sensor by turning the crank to 26 degrees BTDC and using proper tool. I forget the part number but OTC makes them. (4769?) You'll probably have to take off the passenger valve cover to confirm that both valves are closed on #1 cylinder to be on the right rotation.

creeperxr7
12-17-2007, 05:16 PM
another question what should the vac gauge read when the car is in overdrive going about 70 to 75 mph. shouldnt it read around the same as when its idling.?

David Neibert
12-17-2007, 05:34 PM
Easiest fix for the MAF is to do as was already suggested and get a C&L meter with the proper sample tube. You can purchase them from a variety of places, but suggest you buy from someone familiar with the 3.8 SC calibrations...like Dave Dalke, SCP or Spinning Wheels

David