Guest JimR Posted January 31, 2015 Share Posted January 31, 2015 (edited) Already thot about that one, intake clear, turbos freespooling,disconnected intercooler outlet pipework and ran engine. Air blasting out. at least its another possible out of the way. on your mention of a stable idle. I do not have any idle. Sent you a couple more pics yesterday after work. - - - Updated - - - Edited January 31, 2015 by JimR Duplication (see edit history) Quote Link to comment Share on other sites More sharing options...
CanisLupus Posted January 31, 2015 Share Posted January 31, 2015 As Chris said,check all signals at the ecu not at the sensor. Chances are that the new loom has a problem too if it is used. Map,ect and intake air Temperature have to send correct signals for the engine to run smooth. Fuel pressure on the stock ecu should be set to 3bar when not running and should sit around 2.5 when running with Vakuum reference. Other than that try pulsing the injectors manually with a short piece of wire from the battery and listen if they are clicking. Be aware and don't do this when there ist fuel pressure or you will flood the engine. Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 1, 2015 Share Posted February 1, 2015 Decided to check the injectors as they were in the area of the fire. Stripped out throttle body, plenum chamber to give easy access. a resistance check on the injectors showed 15 ohms. All were exactly the same. Not sure if this is correct. I am assuming that they are standard 440cc jspec injectors. Will remove rail and do flow test next week after i can arrange some extra fuel lines. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 1, 2015 Share Posted February 1, 2015 If you had access to a means of measuring injector dwell time I could could tell you whether the ecu was holding them open too long, or if the dwell was about right, but for some reason the injectors were supplying too much fuel. Some old automotive multimeters had a dwell switch setting for setting contact points. Most garage "engine analysers" will have this available, too. Any thoughts on mailing me the ECU? Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 1, 2015 Share Posted February 1, 2015 I remember the dwell meters for your points. I may even have one in my garage that I have not used for years, If not Will ask around see if I can find. Is the 15 ohm resistance reading ok? I think sending you the ECU is an excellent idea, though there are some issues, I would need to pay courier charges both ways, VAT to send out, duty and VAT to bring back. by the time I pay all this I may as well buy one in the UK and have it shipped. I beleive Keron has one, I am waiting on a response from him on it. Quote Link to comment Share on other sites More sharing options...
chrispot Posted February 4, 2015 Share Posted February 4, 2015 i have not read through all the posts, but could it be the fuel pressure reg got damaged in fire causing it to stick and giving too high a pressure? regards chris Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 4, 2015 Share Posted February 4, 2015 (edited) Very good point, but Jim seems to have covered this in Post #20: "Hi Chris. Please check my last post on the map sensor, Vacuum at the FPR is OK. Fuel pressure I can adjust. before all this happened I was running 3.5 bar fuel pressure, but now if I raise the fuel pressure the car does not want to start because of the overfueling, If I lower the fuel pressure to 1 Bar the car actually runs better, but this again is related to the over fueling problem. I do not have access to another ECU. Trying to rule out all other possibles before trying to purchase one from UK only to find I still have the same problem." My best guess is either the injectors are suspect or the ECU is kaput. Injector dwell time (duty cycle) would be the most useful info. Actually, if Jim can't lay hands on an old automotive diagnostic meter with a dwell function, he could get a comparison by measuring the voltage as accurately as possible between engine ground and the live side of an injector, engine running at a given RPM. Then measure the voltage across the injector wires. From this it can be derived what the approximate duty cycle is. Compare to a known good runner... Example, injector live side to engine ground 14 Volts. Across the injector 7 Volts. Approximate duty cuticle is then 50% Edited February 4, 2015 by Chris Wilson (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 5, 2015 Share Posted February 5, 2015 Thanks for this Chris, not managed to do much on car, been busy at work. As I said I did a resistance check on the injectors, all were 15 ohms, since then I have pulsed them with a 12v signal from the battery, then ground the ECU feed, all appear to be functioning ok. Still looking for dwell meter. I can measure the voltage to injectors but. Stupid question. How do I measure the voltage across them, do I just measure the ECU feed to earth? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 5, 2015 Share Posted February 5, 2015 Just set meter to measure volts and pick an injector. One probe to each injector wire. Then measure running voltage, one probe to injector feed side, one to clean engine metalwork. Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 5, 2015 Share Posted February 5, 2015 thanks will try that as soon as I get everything back together, unfortunately I will be away all of next week in Jo'burg. Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 13, 2015 Share Posted February 13, 2015 Back from Johannesburg, without getting hijacked. With the plenum chamber removed while working on injectors, i have checked the IACV appears to be good resistances are within the spec given at 23ohms. operates as it should. but I have now also tried a resistance check across the terminals of the Inlet air temperature sensor and get nothing. Should I be getting a resistance here, cannot seem to find any spec in the manual. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 13, 2015 Share Posted February 13, 2015 Is it showing open circuit, or shorted? I would guess it should have similar to my ATS04 sensor, about 3k ohms http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=13&cad=rja&uact=8&ved=0CHAQFjAM&url=http%3A%2F%2Fwww.pim-engineering.com%2Ftiedostot%2FMagneti_Marelli_sensors.pdf&ei=ubTdVOCML8S07gaH04HwDQ&usg=AFQjCNE4UdWeSsGhzeH_7CCykCumttlNfQ&sig2=up99a1V5xUD3qTM61MIQ5A&bvm=bv.85970519,d.ZGU Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 13, 2015 Share Posted February 13, 2015 it is showing open circuit no reading at all. could this cause my overfueling to the extent I am having. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 13, 2015 Share Posted February 13, 2015 Hi Jim, glad you safely negotiated the wildlands of Jo'burg! If you look at the pdf file you will see the "Characteristic Curve" for a likely similar device. When the air temp is cold it's resistance is very high. In fact it reads about 101k Ohms at -40C Conversely, if the air is hot, it's resistance is much lower, at about 125 degrees C it's about 100 Ohms. So if it goes open circuit the ecu may do one of two things. Ignore it as an impossible figure, and fall back to some base map for the sensor, and probably flag a fault code. Or see it as a valid reading and think it's in liquid nitrogen and go mad rich. I doubt a modern ecu would do the latter. I have to best guess based on what I *KNOW*. A stock ecu with a faulty water coolant temp sensor will make the car really hard to start from cold as the ecu defaults to "seeing" a mid range temperature, so it will run reasonably when warm, but is too weak to start easily from stone cold. It also flags a fault code. So all I can suggest is see again if there's a fault code, and wonder why not if there isn't. If you have access to resistors you could either connect one of about 3k Ohms across the connector plug that would go to the air temp sensor, or find a small variable resistor (potentiometer) and connect the centre terminal and one of the two end terminals across the plug. Try and find a potentiometer of about 5k ohms and fiddle with it with the engine running. I would be surprised if an open air temp sensor would cause over fuelling of the scale you describe though, very surprised. I have a Supra engine in bits, but when it's back together and running I'll try disconnecting it and see what happens. Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 18, 2015 Share Posted February 18, 2015 Hi Chris, I managed to finished my injector flow test on Monday, all injectors operating properly,opening,closing,no leakage. All giving a total of 480cc/min at 3bar pressure. A friend ofmine was here today he has a Toyota Soarer, 1JZ TT. His car uses the same Intake air temp sensor and MAP sensor. We fitted my IAT sensor to his car and ran it. Made no difference, but his ECU did throw up an error message. Next we tried unplugging his MAP sensor, ran the car immediately he had a loss of power and overfueling to the extent that we could smell the petrol from his exhaust box. I am getting none of these error messages. Tomorrow I will pull the plugs from my ECU to check plugs and terminals, will also try to do a continuity test from the ECU plugs to the sensor plugs. But I am afraid it looks more and more like I may be looking for an ECU. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted February 18, 2015 Share Posted February 18, 2015 Yes, does sound like an ecu issue to me, the offer stands should you want to send it over, I can try it on a known good engine package. Quote Link to comment Share on other sites More sharing options...
Guest JimR Posted February 19, 2015 Share Posted February 19, 2015 What about the offer to sell me the known good one that you have? Or should I maybe advertise on the site to see if anyone has upgraded their ECU and has a spare Stock Toyota one? Anyone reading this who may have one please let us know. The Car is a stock JDM 1993 Supra TT 6 spd manual. The part number on my ECU is 89661-14501. If this helps. Quote Link to comment Share on other sites More sharing options...
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