Engine power falls flat about 4800-5000 to redline
07-23-2006, 07:29 PM
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Engine power falls flat about 4800-5000 to redline I have been loogging my 98 m6 vet recently to determine what the cause of the engine power loss was. It happens when I go into wot and got past 4800 rpm. The car pulls hard and strong then just dies off. I noticed no knock, a steady 26.5 degrees of timing. o2's leveled out at 930's mv on both banks from 3500 to 6400 rpm. Ipw stayed steady and progressively went up to about 78% @ 6400. Throttle percent was 99.6%. I did notice that grams per cylinder was @0.80 at 4800 then dipped down and went back to 0.80 @ 6400 when I let out the throttle. I do have a log file that I can email anyone that would like to help me. Plus I have a tune file also.
Car has a cheatr cam, patriot gold springs, ls6 intake, z06 manifolds and hpipe, borla catback, and efilive tuning.
Car has a cheatr cam, patriot gold springs, ls6 intake, z06 manifolds and hpipe, borla catback, and efilive tuning.
07-23-2006, 10:45 PM
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Does it do it at any vehicle speed? The only reason I ask is because I have seen this happen when the traction control sytem is malfunctioning, maybe do to the wrong size rear tires compared to the fronts, where the computer actually thinks the rear tires are spinning and the traction control comes on trying to stop the "false" wheel spin. Try it with the traction control off and see what happens.
07-24-2006, 10:56 PM
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I have this problem too I am going to sub this thread and as soon as I get my air box made I will try to do some testing to determine the cause. One of my problems was my air box. Does your map and maf readings climb through this range
07-25-2006, 03:33 AM
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I have what reads to be the same problem, only my power loss comes between 2000 and 3000rpm. I've taken it to a pretty good sized dealership to try and solve this with no success. They ruled out the fuel system and all sensors, saying my next step should be the MAF or computer. A solution or idea would be appreciated.
07-25-2006, 02:26 PM
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Its funny you guys said something about voltage problems. My alternator went out about a month ago. But had this problem way before the alternator went out. Maybe my problem with the engine falling off is to do with why the alternator went out?
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07-25-2006, 09:19 PM
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ok i have a stupid ? how exactly do you log the coils. I watched misfire and used the status bit for the coils but had no luck. My values were 0 misfire and status on coils where ok any other Ideas. I'll try a new fuel filter tommorow. I also changed the air filter and it helped but my cynamic cyl air goes flat at 0.66g/cyl around 4000rpm and holds that value to redline at 7200 rpms. Again I am open for new ideas.
