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Cutting and sputtering at 3000rpm and above

 
Old 03-20-2011, 02:03 PM
  #16  
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Group buy on Optima is on now, I got one!!
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Old 03-21-2011, 12:35 PM
  #17  
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I am going to have my battry tested and go from there.
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Old 03-21-2011, 01:07 PM
  #18  
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It smells like it is running very rich and I now smell like gas but when I look at the AFR in the Power perfect software it says that it is running a 13.6 to 14 unloaded anywhere in the rpm range. I must say that it is running a little bit better today than saturday. I am going to bring in my AEM wide band in and see what it is really doing.

John, I had the motor rebuilt from Lindsey Racing late last year. I have not run the car much sence then but it seemed to run fine late last fall. If I floor the gas pedel fast it backfires and falls on its face, but if I accelorate medium to slowly it runs just fine. Again it smells very rich of fuel.

Before I had my motor rebuilt, I was running a '3' in every box of the Power Perfect software.
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Old 03-21-2011, 01:57 PM
  #19  
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If it revs up fine standing but it sputters on acceleration my money is on a boost leak. Check the hard pipe connections especially the J boot. Also check the bolts that hold together the wastegate halves.
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Old 03-21-2011, 05:10 PM
  #20  
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I just checked for leaks. I did not find one. I have a tail wategate than is fairly new so I dont think that it is would leak there. I did have my battery checked and found out that it is bad so I am getting a new one. Mine is under warranty so that is good. Would a bad battery cause this?
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Old 03-21-2011, 05:24 PM
  #21  
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Did you check voltage at the battery while revving the engine? Could it be possible that your alternator is ready to give up the ghost? Maybe someone more experienced than me can chime in and tell you if that is a possibility or if I'm barking up the completely wrong tree.
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Old 03-21-2011, 05:47 PM
  #22  
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Use your WideBand to determine the AFRs.
Since the setup worked fine last year, then I would look at the many possible causes of running rich (not in any order):
- Vacuum leaks
- Ground issues
- Incorrect Fuel Pressure
- FQS setting
- Engine Temp sensor
- Dirty/oily MAF sensor
- O2 sensor (Idle and PT)
- TPS

Most have been covered on this forum.
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Old 03-21-2011, 06:42 PM
  #23  
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Originally Posted by fast951 View Post
Use your WideBand to determine the AFRs.
Since the setup worked fine last year, then I would look at the many possible causes of running rich (not in any order):
- Vacuum leaks
- Ground issues
- Incorrect Fuel Pressure
- FQS setting
- Engine Temp sensor
- Dirty/oily MAF sensor
- O2 sensor (Idle and PT)
- TPS

Most have been covered on this forum.
Vacuum Leaks: None
Ground Issues: Everything is clean and new. I even ran another ground strap from the bell housing to the neg. on the battery.
Fuel Pressure: I did install a new HV fuel pump with new filter. I did not touch my adjustable fuel pressure regulator but I will reinstall my guage to the front of the fuel rail. 3 Bar is what I believe it should be at.
FQS setting: I believe that I am running all the way counter clock wise. Which is 0 stock setting. I did not need to touch it from that setting when I first got your system. Would it change with a motor rebuild??
Engine Temp Sensor: At $10 it would be worth it to rule that out..
MAF: Mine is clean as could be. Maybe 800 miles sence new.
O2: I did get a new after market one which had to use some weird concetion to attach it to the factory wiring. If the wires were backwards would it cause a problem. It seems to read in the Power perfect software just fine.
TPS: It will rev up nice and smooth, but under load or floored fast it stumbles and back fires. Also on the freeway it seems to have a problem getting past 3000 rpms but once past it seems to be better. Still not perfect but better.
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Old 03-21-2011, 07:28 PM
  #24  
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Originally Posted by Richgreenster View Post
O2 sensor I did get a new after market one which had to use some weird concetion to attach it to the factory wiring. If the wires were backwards would it cause a problem. It seems to read in the Power perfect software just fine.
Are you using the SMT6 based PB? Power Perfect is something else...
Are you using the AFR readings, or are you using the O2 voltage. One of the documents I provide has a table showing what you should be looking for and how to interpret the data. You should not be looking at AFRs.

Originally Posted by Richgreenster View Post
TPS: It will rev up nice and smooth, but under load or floored fast it stumbles and back fires. Also on the freeway it seems to have a problem getting past 3000 rpms but once past it seems to be better. Still not perfect but better.
Backfires from exhaust means rich. So now you have to figure what changed to cause it. I'm still not ruling out a pressure leak or fuel pressure.
Can you drive the engine pass 3000RPM without boost?
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Old 03-21-2011, 07:48 PM
  #25  
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Originally Posted by fast951 View Post
Are you using the SMT6 based PB? Power Perfect is something else...
Are you using the AFR readings, or are you using the O2 voltage. One of the documents I provide has a table showing what you should be looking for and how to interpret the data. You should not be looking at AFRs.I will have to pull out the papers you sent me.
I am running the SMT6. The Program says Power Perfect but it is the smt6 older version. (Pink Unit)



Backfires from exhaust means rich. So now you have to figure what changed to cause it. I'm still not ruling out a pressure leak or fuel pressure.
Can you drive the engine pass 3000RPM without boost?
My shop used starter fluid at all of the conections from the intake to the TB. They also checked the intake manifold at the block. I checked the vacuum lines and they hold vacuum. I did not check at the Wategate. The mechanics in my shop do not understand the system but are sure and willing to bet me that it does not have a pressure/Vacuum leak.
I will reinstall the fuel pressure guage on the front of my rail. 3 Bar right?
I can drive the engine past 3000RPM without boost but on the free way it is hard to do. I suspect it is because it has more load on it. The strange thing is that it seems to be right at 3000RPM where it goes bad. 2999 RMP it is ok 3000 RPM it backfires and falls on its face.
I cant to much more to it today because I have the battery out of the car and a new one comming tomarrow under warranty. Also tomarrow I am going to bring in my Wide Band and hook it back up on the car to see what it is doing.
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Old 03-21-2011, 08:27 PM
  #26  
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Perfectpower (SMT6) and power perfect are two different entities. I do recall you purchased the SMT6 used.. regardless, it does not make a difference.

You need to "Pressure Test" the intake. Holding vacuum does not mean it holds pressure. Vacuum pulls in, pressure pushes out. So under boost, a hose can be blown out to leak.

The 3000RPM makes me question a few things: TPS is one of them. I also wonder if you are somehow telling the V-FLEX to shut down. It kicks in around 3000 RPM and requires a bit of load, this is by design to allow you to limp home if needed.

Disconnect the PB and run the coding plug in its place. See if it makes a difference.

For fuel pressure follow the instructions you should have (and hopefully saved).
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Old 03-22-2011, 03:29 PM
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John, How much will you sell me a coding plug for?
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Old 03-22-2011, 09:43 PM
  #28  
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Default Did you check the wires to make sure you're not getting a crossfire?

Try swapping out the plug wires or looking for an 'arc in the dark' when revving past 3K. Classic symptoms.
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Old 03-22-2011, 10:07 PM
  #29  
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What kinda bypass valve have you got(rubber diaphram stock ?)My car was do'ing pretty much the same thing. you might have a torn diaphram.....just a guess.........
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Old 03-23-2011, 04:16 PM
  #30  
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I have a new forge. I dont think that it is comming from there. I need to spend some time on the car to run some tests. Right now I am thinking that it is either a boost leak or the TPS. The New battery did not help so I can rule that out. I will keep you guys updated as to help anyone else with this issue.
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