Guest roliks Posted December 3, 2007 Share Posted December 3, 2007 Hey guys... I have a couple questions that hopefully you can help me solve. I have a USDM 93.5 MKIV TT Built Auto w/3600 stall, T61 turbo, EGR blockoff plates, intake, exhaust, TIAL BOV/WG and a MBC and BCC. Everything else on the car is stock. (sidemount, fuel, traction control, etc...) On a cold start my car doesn't want to start... almost like its not firing and it just sits there and cranks or spits once then cranks for a couple seconds till I stop it. Now once I crank it after some time and some gas or starting fluid she will fire up and run rough for a couple of seconds (it seems just to warm up a little bit) then she runs fine. Now I have a feeling that the seconds is directly related to this but I haven't found an answer yet.. obviously as thats why I am here. The other thing is that the Trac Off light flashes then the OD light starts blinking... then it stops for a long time... then randomly it will do it again.. and stop. I have checked the connections and all are snug. I just replaced the sub TPS (Traction control sensor (TPS #2)) as I was told this was the problem. And its still doing it. It can be while I am sitting the car will run fine and be idling and the light will come on and then the OD light will start to blink. Then both will stop at random. Now when the light blinks the throttle seems to hesitate before catching up. When the light is off the car runs fine.. (Minus the cold start issues) There are no codes being thrown just the random light flashing. I have a SAFC that I am getting ready to put on but I would like to have the issues fixed before I start doing things to her. I would like to add that I just put in new coil packs and I have cleaned the IACV. Help is greatly appreciated and needed. Sincerely, -Skilor Link to comment Share on other sites More sharing options...
Guest roliks Posted December 7, 2007 Share Posted December 7, 2007 Does anyone have any ideas? Link to comment Share on other sites More sharing options...
Carl_S Posted December 8, 2007 Share Posted December 8, 2007 "after some time and some gas or starting fluid she will fire up" so you get her to start after doing what exactly? Link to comment Share on other sites More sharing options...
gaz1 Posted December 8, 2007 Share Posted December 8, 2007 so you have a single set up being controlled by the stock ecu, standard fueling, what bar are you running, is it stock fuel pump too Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 9, 2007 Share Posted December 9, 2007 You have done quarter of what's needed to run a single, expect serious problems soon, like it'll blow up. It needs a proper aftermarket ECU and professionally mapping. Link to comment Share on other sites More sharing options...
Guest roliks Posted December 10, 2007 Share Posted December 10, 2007 Its only when she is cold. It was semi warm here today and she started up just fine. Not even 2 seconds of cranking and she was running. When Its cold I have to crank it for a while and possibly spray starting fluid. I don't pump the gas or anything Its almost like either the fuel pump is not priming the system or there is not enough spark to ignite the fuel. Yes its a stock ECU. I am running 12psi (stock pressure)= 0.827369 Bar. Yes stock fuel pump. It has been proven that the USDM stock ECU and fuel system can and does support single turbo and or twins up until 500HP. I am running way under that so I know my system is ok there. I do have a SAFC that I will be putting on but wanted to iron this out first. Link to comment Share on other sites More sharing options...
JustGav Posted December 10, 2007 Share Posted December 10, 2007 It has been proven that the USDM stock ECU and fuel system can and does support single turbo and or twins up until 500HP. I am running way under that so I know my system is ok there. WHERE????? This I've got to see.... Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 10, 2007 Share Posted December 10, 2007 Sorry, only just seen you are in the USA, the physics book is different over there, like many things. Link to comment Share on other sites More sharing options...
Guest roliks Posted December 10, 2007 Share Posted December 10, 2007 Taken directly from http://www.mkiv.com http://www.mkiv.com/faq/faqtt.html fuel rail and injectors: the stock fuel rail and injectors are quality units, capable of supporting the same HP as the stock fuel pump. the injectors are rated at 540 cc/min at 41.2 psi of fuel pressure (~550 cc/min at 43.5 psi), and are a two-hole, side-feed, low resistance design. these injectors enable the hot injector to be cooled by its fuel supply, increasing both hot starting and drivability. push your power past 475 rwhp, however, and your exhaust gas temperatures (egts) may climb due to a leaning-out condition. those pushing the limits of the stock system will need to keep a close eye on this. it would be a good idea to have your injector cleaned and balanced if you plan on pushing 500 rwhp on the stock system. Link to comment Share on other sites More sharing options...
Guest roliks Posted December 10, 2007 Share Posted December 10, 2007 Sorry, only just seen you are in the USA, the physics book is different over there, like many things. Np. Thanks for the input though. It is appreciated. Link to comment Share on other sites More sharing options...
JustGav Posted December 10, 2007 Share Posted December 10, 2007 Taken directly from http://www.mkiv.com http://www.mkiv.com/faq/faqtt.html fuel rail and injectors: the stock fuel rail and injectors are quality units, capable of supporting the same HP as the stock fuel pump. the injectors are rated at 540 cc/min at 41.2 psi of fuel pressure (~550 cc/min at 43.5 psi), and are a two-hole, side-feed, low resistance design. these injectors enable the hot injector to be cooled by its fuel supply, increasing both hot starting and drivability. push your power past 475 rwhp, however, and your exhaust gas temperatures (egts) may climb due to a leaning-out condition. those pushing the limits of the stock system will need to keep a close eye on this. it would be a good idea to have your injector cleaned and balanced if you plan on pushing 500 rwhp on the stock system. Still don't see the bit that says the stock ECU is fine (which it REALLY isn't and that is obvious) Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 10, 2007 Share Posted December 10, 2007 In fairness to you, it still should start OK, hot or cold, you do still have the stock air flow meter? Check for fault codes, could be a water temp sensor, or even the air temp sesnor in the AFM. I am NOT condoning the set up, it's wrong and will never run right under load, but it SHOULD still start ok Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 10, 2007 Share Posted December 10, 2007 Can you answer one question, are you running this set up without using a wide band AFR gauge:innocent: Link to comment Share on other sites More sharing options...
Guest roliks Posted December 10, 2007 Share Posted December 10, 2007 In fairness to you, it still should start OK, hot or cold, you do still have the stock air flow meter? Check for fault codes, could be a water temp sensor, or even the air temp sesnor in the AFM. I am NOT condoning the set up, it's wrong and will never run right under load, but it SHOULD still start ok Yes sir I still have the stock MAF. There are no fault codes (unfortunately... it would be easier to diag). Once this is fixed there will be an install of the SAFC, wideband and a VPC, if I can ever find one with the chip for the auto. She is down for the winter and I am getting ready to start the upgrades soon so don't worry a fuel system is coming in January. Injectors, pump, lines, rail, the whole bloody mess. I just wanted to diag this before I start putting things on it as I agree it should start and idle fine. My thought is why take a supra with some things that need to be fixed add a bunch of upgrades to it and then try and figure out what is messing up. It should be easier to get the base set then start doing multiple upgrades. Then if something doesn't work its easier to diag later. Link to comment Share on other sites More sharing options...
Guest roliks Posted December 10, 2007 Share Posted December 10, 2007 Can you answer one question, are you running this set up without using a wide band AFR gauge:innocent: No there is no wide band on it as of yet. That is to be put on in January. The car isn't driven and no load is put on the vehicle. Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 10, 2007 Share Posted December 10, 2007 Get a `scope on the injectors and see what dwell time they have on start up, and go from there. It's either fuel or ignition or timing, and you say throwing in excess combustant fires her up, so I would guess fuel. It runs OK warm, so hence I'd guess something that controls fuelling during cold start, hence water or air temp sensors or their wiring. A very weak spark MIGHT cause it, too. Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted December 10, 2007 Share Posted December 10, 2007 Yes i would check the ECU water temp sensor first, failure of these after a few years is quite common, i have had this on a few cars. Link to comment Share on other sites More sharing options...
TLicense Posted December 10, 2007 Share Posted December 10, 2007 It'll be one of two things. Either too much fuel, or not enough. You can rule out too much by balancing things up a bit by opening up the throttle body whilst cranking it. If that makes it worse then it's not enough. Possible causes are either fuel supply problems (pump / FPR / Injectors) or signal input problems (Water temp sensor / air temp sensor If it were a spark problem, I imagine you'd be complaining of it missing under load, which your not so I would rule that out initially. Link to comment Share on other sites More sharing options...
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