dr_jekyll Posted July 11, 2010 Share Posted July 11, 2010 i recently serviced the supra , spent a fortune all the fluids are fresh vam belt,pullys ect, all the filters are fresh new ignition leads , new dizzy and new rotor. now , before i serviced it it was spooling fine but missfireing at the top end of the high gears. so i thaught a full service would cure it , noe it dose not miss but the tubo dose not boost untill 5200rpm where as it used to boost at 3800. now as the boost is not comeing in soon enough the fueling is now all wrong so it just bogs down. what could be the reason for the huge amounts of lag im geting. there is no play in the shaft and its spins freely by hand any help apriciated. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 11, 2010 Share Posted July 11, 2010 I'm assuming this is an NA-T as you say you've got a dizzy? As you changed the rotor, could you have altered the ignition timing? It'd easily cause a lack of power and poor spool if it was retarded several degrees. The fuelling should be done by revs vs boost, your map should still fuel correctly for less boost as it's the equivalent of less throttle, so the bogging down would be caused by something different. What ECU have you got in place? Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 11, 2010 Author Share Posted July 11, 2010 i have a greddy emanage blue, it has just been mapped by ryan G , the rotor housing has not been moved and was pre marked to make sure. Quote Link to comment Share on other sites More sharing options...
JamieP Posted July 12, 2010 Share Posted July 12, 2010 what could be the reason for the huge amounts of lag im geting. there is no play in the shaft and its spins freely by hand any help apriciated. Split the turbo open, my money is on melted blades. Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 12, 2010 Share Posted July 12, 2010 Split the turbo open, my money is on melted blades. It's a big failure suspiciously straight after the service, but it's certianly worth a check if the timing is ok. If Ryan mapped the EMB then it'll be fuelling right for the whole boost/rev range so it won't be overfuelling. Unless something has gone wrong with the EMB or something, check the map is still on there if you can. I've never heard of an EMB 'losing' it's map but hey. Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 13, 2010 Author Share Posted July 13, 2010 im thinking its possibly the turbo , its starting to make a high pitched squeal , almost like a metel on metal sound. im thinking the over fueling came because on wot @4k the car is mapped to be seeing 8psi and is adding fuel but due to what i think is a failing turbo its not boosting up. i have read these gt4088s are common for the hot side going so whaen i feel the will power to even look at the car again ill take the turbo off and have a look. im starting to feel like i need a no nonsence big na v8 in my life Quote Link to comment Share on other sites More sharing options...
Nodalmighty Posted July 13, 2010 Share Posted July 13, 2010 I'm starting to feel like I need a no nonsense big NA v8 in my life In the Supra? Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 13, 2010 Author Share Posted July 13, 2010 In the Supra? maybe something lighter, some scaffolding with a plastic body sat on it Quote Link to comment Share on other sites More sharing options...
Ian C Posted July 13, 2010 Share Posted July 13, 2010 im thinking the over fueling came because on wot @4k the car is mapped to be seeing 8psi and is adding fuel but due to what i think is a failing turbo its not boosting up. No no, chap, that's a common misconception with turbocharging The car could see any boost pressure at any revs at any throttle position depending on load on the engine. For example, wide open throttle at 4000rpm when in 1st gear going downhill and you only just went WOT, well, you'd see probably 2 or 3 psi. Whereas wide open throttle at 4000rpm when in 5th gear going uphill and you've had it planted since 2000rpm, you'll see full boost, say 21psi. Quite the difference, but the same throttle position and revs So the map needs to cater for all boost pressures at all rpms. Well, within reasons, I mean 500rpm, 21psi boost isn't ever going to happen but you get what I mean. So if you leak boost or the turbo doesn't spin up fast, it'll still be fuelling correctly, just on a different (lower boost) part of the map for that RPM load site. Doesn't help you with your problem but as I said, it's a common misconception about turbo'd engine maps Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 19, 2010 Author Share Posted July 19, 2010 i understand , thanks. allways learning. anyhow i split the turbo today and it is like new to my suprise so the search continues. Quote Link to comment Share on other sites More sharing options...
dr_jekyll Posted July 20, 2010 Author Share Posted July 20, 2010 by george i think iv got it . after hours of taking things off the the car then taking them apart . it seems a have a small split in a pice of i.c pipe on a 135" elbow :donkey: so ill buy a new elbow. putit all back together and fingers crossed all should be well Quote Link to comment Share on other sites More sharing options...
Smallshinyant Posted July 20, 2010 Share Posted July 20, 2010 Well done Dr Watson, lets hope that does it. Good luck getting her back together. Quote Link to comment Share on other sites More sharing options...
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