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THANKS A TON! I have posted this info several times with no luck! Do you have a program that changes these into graphs? If not, you have an incredilbe ability to read these in table form! I have tested for leaks a lot, fixed several --- I have one on the lower part of the EGR, but EGR operation is normal --- I understand this is a common leak and shouldn't affect things much. I also have one on the drivers side exhaust valve cover. I don't know if I have others...my boost holds STEADY no matter what I set it to, I do know that....10, 15, you name it. Also, the performance doesn't change if I up it to 15...it just hits 4500 or so and levels out badly. I tried someone elses MAF --- his voltages were similar and the performance with his on was similar. I have not tried a CAS yet, but that's high on my list (see a post I made RECENTLY below). Power loss indeed is most noticeably in higher gears (3rd and 4th, 5th, too). I've checked the spark plugs -- they are "young" and look good, but I have brand new ones ready to throw in. The plugs were gapped to .035 from the get go. All the connectors are SHINY and have no green oxidation -- however, I lost a cylinder once and got it back just messing with things a bit, so there could still be an issue there. I also did not bend the connectors like many do to ensure constant contact. All injectors check out good with ohm/click. Each injector clicks with CAS revolution -- HOWEVER, this could be a high rpm problem entirely that wouldn't show up with 1 rpm test : ) I really need to get a CAS on my car --- I think that might solve it. It's just "one of those things" that's so easy to do, but I haven't done it. Anyway, again, I really thank you for your response...no one has been able to say what you have said. When I try to get my alphas (air/fuel, right?) the program locks up --- it also eliminates them as an option when I CHECK FOR REGISTERS. Perhaps the program/consult tool I use is not effective enough for this kind of trouble-shooting. I have no idea what a 3rd Order Polynomial trend is, but I'm guessing you mean that a third measurment with the RPM and AIRFLOW might provide many answers??? I'm headed to the DYNO tomorrow --- hopefully it will give me some useful info. -Dave :Well, if your CAS is OK, then mine is too. RPMs charts look the same as far as steadiness. Actually, your RPM charts are a bit more erradic than mine, so you might actually have a CAS problem.
:Couple of comments on your logs.
:1) Your TPS looks unsteady. When you have it floored it jumps around quite a bit.
:2) If you do a graph of just your MAF against RPM, you'll see that the airflow is *highly* variable. Too variable. I've compared your graph against a number of my own logs and mine are relatively smooth.
:3) In particular, your airflow gets whacky in 3rd or 4th gear after 4600 RPMs when your engine has reached peak torque and peak boost. During your 1 2 3 shift, the 3rd gear acceleration shows a sudden decrease, not just flattening of airflow. The things that I'd be strongly suspicious of in this case are:
:a) Boost leaks. Have you pressurized your intake to 5 PSI and does it hold pressure for at least a minute. If not, is it leaking past anything but valves.
:b) Ignition failure. Checked spark plugs? Are the TPU connections coated with green oxidation?
:c) CAS failure problem of some sort. Have you checkd your splines for rust? Is there freeplay between the CAS gear and the cam? How is the harness connector? Free of oxidation?
:d) MAF failure? Less likely as it seems to mostly happen above 4600 RPMs, but I'd still check the connector and if possible swap with a known good one(same with CAS).
:Also your logs are missing both left and right long and short term alphas. Throwing a 3rd order polynomial trend on these can speak volumes about what's going on.
Z's Rule! |
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