So are you saying that you arent running a signal hose to your waste gates? That would be super bad and probably would cause your problem as the ecu would be pulling everything back when your boost goes insane.
Just tested my TPS voltage and it does generally sit on .46v BUT! the throttle with the TPS opens before the LHS throttle does and the linkages dont have tension on them at idle so every time you blip the throttle it pretty much closes at different openings - probably nothing to do with the flatspot but a problem none the less in getting a consistent idle
Try regapping one of the sets of spark plugs to .7mm (they should be factory gapped to 1.1mm). Maybe you've got a weak spark in a couple of cylinders and the spark is being "blown out" under high boost?
My problem is fixed! I took of the front bar yesterday to check the intercooler hoses (maybe I had a massive boost leak that wouldn't show up on the boost leak test). All the hoses and clamps were fine. While still looking in that area, I had a look at the blow off valves. Guess what? the RHS BOV came out of the bloody pipe. The clamp snapped under load (I'm guessing). I went for a drive to Bunnings and got 2 new clamp and replaced the ones of the BOV's and now the car is running MINT! Because of this, I'm suggesting that anyone with the same symptoms that I had, should check all clamps and air connections and make sure you don't have any massive boost leaks. I couldn't pick my leak on a boost leak test because it was so big. Good luck Kingy and other people with the same problem. Chris
my problem like this is all sorted now i took the old girl down to the local dyno to check a few things whilst under load as this problem for me only occured under load. it took all of 2 min to work out the fuel pressure was droping under load and as i had a new fuel filter we knew it was the pump so i bought a new after market pump put it in.went for a drive and all was good the problem went away. one thing to note my fuel pressure was good untill the motor was loaded hope this helps some one else
cheers for that!!!! ive been thinking it was the fuel pump but didnt want to go and spend $300+ on one without knowing for sure. also hadnt gotten around to buying a pressure reading gauge yet either. iver tried just about everything except the fuel pump, so looks like i might as well buy one now
Mine turned out to be a broken fuel pressure regulator (one on the passenger's side of the plenum). Easy way to test as well - clamp your return fuel line with some vice grips or brake line clams and go for a quick drive and see if the problem is gone. Simple as that!!
After many many hours of hair removal I belive I've found my problem...... massive over boosting I have large turbos fitted and there was in the past a boost controller fitted ( removed prior to importing), I also have adjustable rods from the actuators to the wastegates My issue seems to be that the rods have been 'set' at a point that left the wastegates slightly open so that full boost couldnt be reached.... wear in the linkages is slight but is there, I may also have had some carbon buildup that may have held the wastegates open a bit more aswell. After a long & fast run is when I noticed the problem first appeared..... the carbon buildup must have been blown out and the heat from the turbos has either allowed the actuator rods to move out of adjustment thus shutting the wastegate fully...... My boost then goes off the dial Massive boost with insufficient fuel results in.... Det sensor kicking in ECU shuts fuel off engine hesitates......... & boost drops..... Det sensor kicks back out ..... ECU turns fuel back on repeat process ever millesecond and hey presto. Obviously the more throttle the bigger the boost and the longer it took to drop that boost, therefore HUGE flatspots at full throttle. Other things Ive noticed now I've had time to sit down and actually go through the whole process...... 1/ The vacume guage..... normal opperation @ idle, but..... it would smack the +7 mark at 1500rpm mark hard and fast. 2/ Turbos ...... the scream was much louder than normal, especially around the 3000rpm mark spooling up was twice as loud and much earlier in the rev range 3/ BOV's much louder than before the problem and went off at a lesser throttle position than they usually do. 4/ engine ping..... I'm bloody deaf as, so I didnt hear it, thanks to a mate that has great hearing he picked it up instantly.... thank god for det sensors !! For the time being I'll rig up some sort of control and drop the boost way back down to a safer level..... in the mean time I'm off to search out a new electronic in cab boost controller. Any suggestions Kingy
i Know what you went through i tried just about everything i could think of i fitted a EBC & a riseing rate fuel pressure regulator, i also fixed antying that could be remotely a boost leak. It wasnt untill i put it on the dyno and was able to have my head under that bonnet when it happened that i saw the fuel pressure drop. That i knew it was the fuel pump and the feeling when i fitted the new on and took it for a drive and the problem had dissapeared was unbelivable. :zlove:
