Recently I have had a new 800HP Bosch fuel pump installed. My car was leaning out and it was a fauly fuel pump and a fauly earthing wire. PS my car is a 96 GTST.
Prior to me replacing the pump, the car ran fine, and was sweet when cold, ie you could accelarate out of any gear at any rev, clean through the range.
Now that this new pump is on, the car is running richer. Better of course and more power, but when the car is cold, and this is after I warm it up to around 50 degrees, when you accelarate and keep under 2000 -2500 RMP its fine, as soon as boost starts coming on, the car gurgles a bit and unless you apply more throttle the car suddenly unclogs itslef and launches. But if you change gears etc, it is ok. When you are up to 60km and holding the throttle constant to maintain normal driving speed, it starts hanging back, so you give more throttle, it gurgles a bit more and hits boost.
When the car is warmed up, to 8-0 degrees, and you are cruising at 60, you can accelarate and be miles away from using boost and its ok.
These symptons sound like too much fuel when the car is cold. All the above is based on driving at 0.5 bar. If you run say 0.75 bar, its even worse. The car when it bogs down seems to be corrected by a flick in nuetral, rev it out, and keep driving. Although not the quietest cars to do this in!
My mechanics are going to look at it next week, but they already said they adjusted the Throttle position slightly, and said it may also be the Air flow meter.
Also, the dyno chart, the car made 190rear wheel kilowats and the fuel line was (AFR) did not exceed 12 nor fall below 10.5 if this means anything?
Who knows anything about this.
A car no matter what, ie new toyota for example, should be just as responsive and smooth whilst cold, or hot. There should be no difference at all. Can anyone help?
Paul:(