hodge Posted October 27, 2006 Share Posted October 27, 2006 I have a 1993 j-spec tt will this fault stop the car from starting. I know its a MAP or MAF sensor fault, its just the car wont start at all, it will turn over but wont fire. Link to comment Share on other sites More sharing options...
Ian C Posted October 27, 2006 Share Posted October 27, 2006 If the ECU has lost the MAP sensor then chances are it won't start up. I've no idea if that's the case for real though. -Ian Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Is the map sensor the small black box on the throttle body its got snesor turbo pressure on top of it or is it the sensor screwed into the throttle body next to it with the plug connector. Link to comment Share on other sites More sharing options...
Lebsteif Posted October 27, 2006 Share Posted October 27, 2006 the map sensor is the small box screwed in your firewall, there;s a vacuumtube leading to it and a plug with some wires Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Turbo side or throttle body side Link to comment Share on other sites More sharing options...
Lebsteif Posted October 27, 2006 Share Posted October 27, 2006 here you go: http://www.archanox.demon.nl/map.JPG Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 There isnt any black boxes screwed into the firewall. Ive got a works diagram on cd n it ses the map sensor is in the side of the throttle body. Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Thats a N/A mate ive gor a TT Link to comment Share on other sites More sharing options...
Ian C Posted October 27, 2006 Share Posted October 27, 2006 http://www.mkivsupra.net/vbb/attachment.php?attachmentid=13939&d=1112558977 Bottom middle annotation. Check it's plugged in. -Ian Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Yeah its plugged in but the car just wont start. Link to comment Share on other sites More sharing options...
colsoop Posted October 27, 2006 Share Posted October 27, 2006 Is the little vacuum hose plugged in underneath the sensor ? Link to comment Share on other sites More sharing options...
Supragal Posted October 27, 2006 Share Posted October 27, 2006 some more info might help: is it turning over just not firing? when did this happen? etc Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Yeah its plugged in. If the map sensor fails will this stop the car from firing. Link to comment Share on other sites More sharing options...
colsoop Posted October 27, 2006 Share Posted October 27, 2006 I am not sure, i remember not plugging in the hsoe in the back of my boost gauge once when refitting my dash. It is plumbed in to that sensor and it idled really badly and almost stalled itself till i realsied it wasn't plugged in This problem started after filling up with a different petrol type didn't it ? Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Yeah I put some bt ultimate in cos the garage I get my super unleaded from is shut for a refurb. I oly put £20 in but the tank was pretty empty when I put it in.I drove it for about a mile to work and left it overnight, when i came out and started it it struggled but started eventually but was really lumpy as if it was gona stall. when it warmed up it was fine. it didnt happed for next couple of days but then same again. Yesterday night i got in it and it wouldnt start at all as if there was no petrol in the tank cos it wasnt even trying, just turning. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 27, 2006 Share Posted October 27, 2006 Have you got an FCD fitted? - If that failed, or a wire has come adrift, that'll give you a code 31. Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 my FCD is connected to my Greedy E01 boost controller ive used the external signal harness to clamp it. I soldered the wires together myself but it cant hurt, ill check the wiring tomorrow. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 27, 2006 Share Posted October 27, 2006 Ideally, get a multi-meter and check the voltage going into the ECU. The E-01 can tell you what voltage it's 'seeing' from the MAP sensor. I have seen an E-manage go faulty and give a code 31 as it was giving no output to the ECU what-so-ever. Link to comment Share on other sites More sharing options...
hodge Posted October 27, 2006 Author Share Posted October 27, 2006 Ive disconnected the external harness that goes to the map wire and bridged them but did nothing. If its the FCD it will have to be a bad connection where the wires join the ECU, its very doutfull but im dona check it tomorrow anyway, atleast I can rule it out if the joints are ok. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 27, 2006 Share Posted October 27, 2006 Measure the voltage going into the ECU. That'll at least tell you something. IIRC, it should be about ~1.26v. My guess is that you're going to be seeing about 5v, in which case the ECU is trying to throw in enough fuel to cope with about +1.5bar, instead of -0.5. Link to comment Share on other sites More sharing options...
hodge Posted October 28, 2006 Author Share Posted October 28, 2006 Ive just done a new fault diagnosis and im getting codes 24, 31 and the o/d light is constantly flashing. Now ive checked the coded and this is what ive got, Code 31 - MAF or ECM, ( I know a J-Spec had a MAP sensor not a MAF so I would assume it would be that. Code 24 - Air intake temp sensor. O/D light constantly flashing. this is Vehilcle speed sensor I think. Any thoughts Link to comment Share on other sites More sharing options...
hodge Posted October 28, 2006 Author Share Posted October 28, 2006 Ive just done a signal test on the E01 for the fuel cut with the ignition on its holding 2.59v and as I try and turn the car over it goes up to 2.61v. Does this shed any light on the subject. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 28, 2006 Share Posted October 28, 2006 Ive just done a signal test on the E01 for the fuel cut with the ignition on its holding 2.59v and as I try and turn the car over it goes up to 2.61v. Does this shed any light on the subject. Was that going into the ECU? - That's atmospheric pressure. ie, no boost, no vacuum, which is correct until the car starts. But that reading only means the MAP sensor is working properly... Link to comment Share on other sites More sharing options...
hodge Posted October 28, 2006 Author Share Posted October 28, 2006 Thats the problem I cant start the car to check it when its running. Ive kept it turning today and it seems to try after a while to start but only with my foot on the throttle, it starts to splutter and chug but wont finally fire properly and there seems to be a strong of petrol for a second then goes away. Ive checked the FCD connections to the ECU and there fine and also have bridged the wires to see if the E01 was the problem but it wouldnt fire then either. Im at a bit of a loss now. ANY HELP WELCOME. Link to comment Share on other sites More sharing options...
Matt Harwood Posted October 28, 2006 Share Posted October 28, 2006 Were those voltages going to the ECU or the E01? Chances are, if the ECU isn't getting the correct voltage, it will be overfuelling and has now fouled up your plugs. Link to comment Share on other sites More sharing options...
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