hi everyone, I've been noticing my cars performance is decreasing over time, any ideas? its mostly from 4k onwards revs just don't want to fly up? its driving me crazy
thnx guys for the quick response . Austen ill disconnect the battery tonight and see how it goes tomorrow morning,
Daniel, boost leak sounds about right theres all this noise and no go, i just had the zorst done wit highflow cat. and new fuel filter is a must tomorrow also.
as for boost leak ive compression tested the whole intercooler system holds 25psi with a 1 psi leak every 30 sec.
just a question, i have a hks 2 stage boost controller when i up the psi to 14 i plant the pedal goes straight to 14 then drops down as revs go up back to 10psi? is this normal? whats causing this?
Thursday, December 02, 2010 - 09:00 pm, by: Daniel Clarke(Dieseltrain)
The Boost controller isnt setup correctly by the sounds of it . Or there is an exhaust blockage . Try dropping the zorst and go for a quick blat if you can .
-bench tested fuel pump - changed fuel filter - check for leaking hoses and piping - changed oil + filter - changed plugs - removed old safc gen1 back to stock - removed down pipe and took it for a thrashing still dropped down from 14 to 10
*after all this it felt a lot healthier, ive also realized that from 1/2 throttle to full throttle theres no difference in power just sounds more constipated.
Sunday, December 05, 2010 - 06:54 pm, by: Joe Aliano(Sexylexus)
Have you ruled out the TPS (Throttle Positioning Sensor)....I just finished fixing up a Uzz31 and went through all the common problems ....Fule pimp bridge , ecu , afm , coils and sparks and whilst they all helped a little the car revs would drop at 3k then up again , in the end I played with the Tps and found that I had to adjust in order for the throttle to know it's correct position. And now all running good
Joe i checked the tps voltage on wot its 3.96 is this correct?
ive noticed my car increases in power the longer i drive it now with the safc removed, so could it be that the safc was stopping the mines ecu from learning? also could the mines ecu have a boost limit set at 10psi.
like when driving in 2nd @ 4k rpm, then plant is jumps to 14 then about 1 sec later is drops to 10-11 ish psi
my exhaust is 2.5dump pipes into 3" down into high flow cat then split to 2x 2 1/4 with bigg mufflers to make it a bit quiet
i just want to say your guys have been awesome helping me track down the problem.
ok im running a hks 2 stage boost controller basicly its a unit with 2 mechanical dials ones for low setting and 1 for high and the design of it is wierd there no inlet and outlet, just 1 inlet the bleeds off the pressure going to the actuators i think i might invest in a electronic one do you have any suggestions?
i was doing a bit of silly stuff around this fairly large bend wen the power suddenly dropped like it was surging, Straight away i thought the fuel is a bit low mayb thats why, So made a U-turn and drove towards a servo, when as i braked then accelerated there was no response at all, but was just idling @ 800rpm after 1sec is pop and chocked then took off no very powerful tho, so filled up and on the way home the performance is oscillating one minute its wheel spinning the next its trying to rev up but can hear a faint flattering noise also when the revs are dropping like a rich runnin V8 im pulling my hair out because it was running really good past few days when i removed the safc gen1
sometimes can hear the flattering noise alot from 4000rpm
could it be stuck injector?, cracked coil pack? i dont where to start visual inspection look good hoses, clamps etc
when i installed the safc i soldered all wires and changed map sensor twice before removing it +gen 1 2nd hand.
good news i cable tied both ends of the map sensor and now im only gettin fluttering in manual mode changing 1st > 2nd @ 14 psi fluttering occurs between 4-5k rpm then power band kicks in right up to redline (awesome power)
could this be the fuel pump changing voltages from 6v > 12v and the fluttering is the dwell time for right fuel pressure?
i found the problem guys when it changes gears the boost jumps up and hits boost cut then drops down a fraction, my question is how id that possible when i have a mines ecu?
yer im sure i bought and installed it myself even pulled it apart to to find mines stamps all over the circuit board, what else could cause flutter at 14 psi?
Wednesday, December 15, 2010 - 10:50 pm, by: Rob Rojo(Rob_tt)
To eliminate fuel cut being the cause, lower the boost to around 10-11psi and see if still has the problem, if it does then you know its not a fuel cut .
It might be worth a Try tightening the line pressure cable up more, it might speed up the shift enough to get of the delay in gear change.
Thursday, December 16, 2010 - 12:26 pm, by: Rob Rojo(Rob_tt)
Sounds like an Earth problem, probably coming loose around corners, go over every earth point from the battery, undo them and give them a good clean and tighten up.