Guest Dibs2k7 Posted August 15, 2016 Share Posted August 15, 2016 Hi all, Pretty new here and love the site the information so far has been great for helping me find niggly little problems with my lovely car however i seem to have hit a bit of a dead end on this one. so lets see the car is a 6sp tt jdm bpu direct from japan imported through the lovely guys at jm-imports, i havent had the car too long and she has developed a weird starting problem when hot. once at running temp if you turn her off and leave for say 10 mins come back and start it back up the revs drop dramaticaly and she sputters and trys to stall with the afr gauge reading 17+ but after 20 secs the idle will work back up and settle itself down again or it will stall however if given a little gas it helps smooth her out. now i have checked as much as i possibly can and so far have replaced and checked boost leaks, cant seem to find any and any original leaks are gone due to replacing most the bad piping ecu coolant temp replaced with toyota one brand new denso 02 sensor fitted old one was stuck between 0.8 - 1.0 (denso is reading fine) plugs are iridum and were gapped when fitted (jm-imports did the bpu for me) two main water hoses replaced due to old ones weeping and full flush done. No error codes IACV cleaned and appears to be working fine Throttle body cleaned, really unsure how to check tps adjustment so wont touch it myself. now the only thing i have been able to find that helps is the fuel pressure regulator, from what i know their should be a vsv before the fpr (unless its only certain models) however all i have is the fpr connected via hose to a y shaped peice of metal with two hoses leading to a couple of sensors? on the side of the head, now if she is struggling to start while hot if i remove the hose from the fpr and block it with a screw my thumb whatever the car instantly picks its revs up and runs fine while starting hot. sorry for the long post but what im asking is, is my fuel pressure regulator biting the dust (its original toyota) or is something else possibly amiss and causing her to do this as when idling and driving she is spot on without any problems or loss of power in anyway. Thanks all for your time and any input will be greatly appreciated. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted August 15, 2016 Share Posted August 15, 2016 (edited) The fuel pump should have a one way valve in it to retain rail pressure. Maybe it's knackered? Is it a VVTi engine? Edited August 15, 2016 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest Dibs2k7 Posted August 15, 2016 Share Posted August 15, 2016 sorry forgot to say it was a 94 model, so no vvti, the fuel pump should be new since it was replaced on the bpu unless im misunderstanding the bpu. thanks for the reply though. Quote Link to comment Share on other sites More sharing options...
BoostJunky86 Posted August 15, 2016 Share Posted August 15, 2016 This is what mine does. Does it do it while driving as you stop at lights etc. Revs drop to the point it almost cuts out. Fuely haze from the exhaust Quote Link to comment Share on other sites More sharing options...
Guest NathanMcbeath94 Posted August 16, 2016 Share Posted August 16, 2016 Mines is currently off the road atm for this exact reason. Started a few weeks back till Saturday it just wouldn't start when hot and would stall as soon as it was. AA said its the crank sensor but getting the garage to go over it and see what they say. Will update you when I can. Quote Link to comment Share on other sites More sharing options...
Guest Dibs2k7 Posted August 16, 2016 Share Posted August 16, 2016 Mines is currently off the road atm for this exact reason. Started a few weeks back till Saturday it just wouldn't start when hot and would stall as soon as it was. AA said its the crank sensor but getting the garage to go over it and see what they say. Will update you when I can. /QUOTE] Thanks for that, be interesting to see what they say mines back at jm-imports in the morning for them to have a look over as im away at the weekend 600 mile round trip so need her tip top, will let you know if they find anything once i get back. Damian. Quote Link to comment Share on other sites More sharing options...
Guest NathanMcbeath94 Posted August 16, 2016 Share Posted August 16, 2016 Thank you mate, il do the same. Seems like a common problem with not a sure fix. Hope it doesn't turn out too be a massive headache! Quote Link to comment Share on other sites More sharing options...
Guest Dibs2k7 Posted August 17, 2016 Share Posted August 17, 2016 Thank you mate, il do the same. Seems like a common problem with not a sure fix. Hope it doesn't turn out too be a massive headache! /QUOTE] well she seems to be fixed for now, turns out the pipe running from the fuel pressure regulator goes into a y shaped piece of metal with two pipes coming from that which lead to two sensors? anyway turns out once she was hot those pipes were expanding and letting air in a bit, pipes have been renewed and for now she seems to be running good, hope this is of some help. Quote Link to comment Share on other sites More sharing options...
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