Hello Testarossa friends My 1988 EU TR stops after approx. 10 minutes, then it starts again after approx. 1 hour, engine run for some minutes and stops again. There is no spark, Both banks are dead, the fuel pumps works. I have approx. 10 volts at the coils during cranking Any suggestions? Can someone help me with a (ignition) wiring diagram? Regards / Pelle
I would look at the fuse box for any signs of melting. How many crank triggers do these TR's have? If one then I would look at that too.
I agree sounds like a bad ign box or power related, check to see if the ecus are getting power when it will not run.
Pelle -- I think I have the schematic that you seek, but, just to confirm, what is your TR engine family number? -- it's shown on top of cylinder #6 (something like F113A040, F113B, F113A, etc.). In order to be readable, the scan of the schematic is a fairly large .tif file (2.1 MB) so please PM your email address to me, and I'll email it out to you. I'm a little confused by your comment about "the fuel pumps works", because, on all version TR, if there is no ignition signal in the LH coil primary, the tachometric relay will not close, and therefore, the fuel pump relays will not close to run the fuel pumps -- but maybe I'm misunderstanding your comment (but, if you've confirmed that you don't get spark during starter motor cranking, that is a clear enough problem ) . Bottom line is that during starter motor cranking you should always get spark and the voltage waveform from the two flywheel pickups should be as shown in these jpegs (these measurements are made with everything connected so IME you need to add some jumper wires at the 2-pin connectors to leave the flywheel sensor electrically active yet have a place to connect the oscilloscope probes or AC voltmeter probes to make the measurement). If you only have an AC voltmeter available, it should measure 5V AC on the white lower flywheel sensor wires (because it's a continuous stream of pulses) yet maybe only a few tenths of a volt AC on the black lower flywheel sensor wires (because there are only a few infrequent pulses). If you confirm these input signals are present during starter motor cranking and you have no spark on either bank -- this would be a bad sign for the ignition ECU (but check/reseat all the related connectors). If you confirm that one of these input signals is missing during starter motor cranking and you have no spark on either bank -- you've probably found the trouble. Good hunting... Image Unavailable, Please Login Image Unavailable, Please Login
Thank you guys for your suggestions I will check the sensors that 91tr suggest, the number on the engine is F.113 B *00652* As I explain first the fuelpumps are running when cranking and a few seconds after.when the engine cut of during driving the tachometer dies as well so that means that even the signal to the tachometer disaper when the engine stop. I'm not so familiar with the electrical system on the TR, I thought that it was 2 complete separate system for each bank with 2 ignition ECU:s but when I read this it sounds like there is another one? However, if you can send me the diagram everything will be clear And when you say good hunting 91tr you are right, tomorrow monday the Swedish Moose hunting starts so I will spend 3 days in the forrest with my 444 Marlin. It should be great if you can send it to me, [email protected] Regars / Pelle
OK Pelle -- I sent the schematic via email so let me know if you have any trouble with the reception on your end. The TR ignition system is separated by a bank basis only after the ECU -- the system is: One set of flywheel sensors sends signals to One ECU, which then runs a separate coil + power module + distributor for each bank. If you have spark on one bank and not the other during cranking -- you'd go after the coil + power module + distributor on that bank; If both banks are dead during cranking -- it's more likely that the flywheel sensors or the ECU have a problem, or there's no power, or a bad ground, etc.. I rechecked the Diagnosis Sheet No 1 that covers the MED 120B ECU (that is ignition ECU used on both of our KE Jet TR), and they are a little more lenient for the AC voltage specs from the flywheel sensors at 1000 RPM: TDC sensor (black) = "more than 0,10" (when measured on a 20V AC scale) Engine RPM sensor (white) = "more than 2,0" (when measured on a 20V AC scale). All is clear on your description of the fuel pumps running during starter motor cranking (as they should even without a tach signal) and your observation of the engine stopping with the loss of the tach signal is a clear indicator that you're looking in the right place -- let us know what you find.
Forgot to add that post #30 in this thread describes some of the other measurements outlined in Diagnosis Sheet No 1: http://ferrarichat.com/forum/showthread.php?t=97603
Finally I located the problem When I saw the wiring diagram it was more easy to figure out where the problem came from. I had one spray can with freon, I ran the engine warm until it died then I cooled down the rpm sensor, no start, then the TDC sensor and the engine started again, I did this 3 times to be sure. I orderd a new sensor (same as Fiat Uno TDC sensor) Thank you Steve for all your help The summer is over here in Sweden so no more driving this year. // Pelle
Glad to give a little support to a fellow TR Owner, and glad that you've got it sorted out. However, it's funny how part sourcing works. I couldn't think of a harder part to get in the US than something for a Fiat Uno -- but sounds perfect for those in your region. You should add whatever information you can to this thread: http://ferrarichat.com/forum/showthread.php?t=125008 (which I fear won't ever be a big thread -- TIA)
