Gloyale Posted May 26, 2007 Share Posted May 26, 2007 relay plug pic [] [1][2] [3][4] this is looking into the relay plug 1and 2 are black/w and have 12v when relay is unplugged, 3 and 4 have 0v. when i plug in relay and backprobe, 3 now has 12v (blue/black to pin 47). relay does not click when i unplug/plug it with key on. replaced relay with a different one from donor harness, and got the same result. # 3 (Blue/black) should not get 12 v. # 4 (Blue/White) should get 12v when 3 is grounded, that is the switching action of the relay. Without the fuel pump relay disconnected, key on, pin 47 should not output any voltage, does it? I also did your disty tests. I have black,green,red,and white wires. black - ground green - 1v red - .5v white - 1v Well the wire colors I reffered to test are the corresponding harness side of that pug. What colors are the wires on the body side of the disty plug Looking at the unplugged disty harness(harness/body side) heres what you should have with key on "" 1 2 3 4 1 (Green/Black wire)should have 10v 2 (Green/Yellow wire) Should have 4v 3 (Black/white wire) should have 4v 4 (Black wire) should have continuity to ground through pin 35 of ECU If all that checks out then try reconnecting the disty and performing the hand crank test to watch for 5v pulses from Black/white wire, pin 21 of ECU If it passes, use the starter cranking test to watch for pulses at the Green/yellow wire, pin 20 of ECU Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 26, 2007 Author Share Posted May 26, 2007 "Without the fuel pump relay disconnected, key on, pin 47 should not output any voltage, does it?" -yes, pin 47 absolutely outputs 12v, with the relay in place. 12v is supplied to the relay and to the coil by the black and white wires. i have triple checked this connection. "Well the wire colors I reffered to test are the corresponding harness side of that pug. What colors are the wires on the body side of the disty plug" -on the body side, i still have black, green, red, and white as well. these were peeled out of the donor harness. i'll go figure out what each one is. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 26, 2007 Share Posted May 26, 2007 I was reading the posts here fellas and it looks to me that pin 47 is the return (ground side) for the fuel pump. Is that correct? If this is so and the ignition system is working as it should be, then the problem may be in the ECU. The 12 volts on the output of pin 47 means the transistor switch inside the ECU is not turning on to allow the ground connection to the pump lead. Unfortunately I do not have any service data right now to check this out and I may be thinking wrongly on this so I will butt out now. Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 26, 2007 Author Share Posted May 26, 2007 disty wires i compared with a plug from a backup donor harness that i have (dont ask). my wires are red - power supply has .48v green - ref sig. has 1.0v white - pos. sig. has 1.04v black - ground .48v coming out of the red ecm power wire cant be right.. i have a ecm stashed at the jy that i can pick up, but maybe i shouldnt plug that in with the blue/black fuel pump wire showing 12v like it is. grrrrrrrrr..... Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 so my HD mechanic friend figures that i've got a bad ecm. I didnt think to be more careful with it than i was (plug unplugging it with the key on and such), so i may have cooked it myself early on. off to the jy i guess. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted May 27, 2007 Share Posted May 27, 2007 "Without the fuel pump relay disconnected, key on, pin 47 should not output any voltage, does it?"[/Quote] -yes, pin 47 absolutely outputs 12v, with the relay in place. 12v is supplied to the relay and to the coil by the black and white wires. i have triple checked this connection. I said with the Relay disconnected. We are trying to determine if there is a short or problem with the fuel pump relay wiring, or if the ECU is actully outputing 12v through that pin. Basically is that 12v coming from the B/w wires through the realy to the pin 47 wire? Or is the ECU outputting 12v from pin 47 And all those Disty wire measurements are off what they should be. Allthough if you have 12v going to a ground signal on the ECU that's not surprising. I can't tell you why you're wire colors are different though all my books through 90 show G/w, G/y, B/w and Black. But either way tha's bad voltage reading that in the flowchart would point at the ECU Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 ahh damn sorry i missed you Gloyale. I was up at the jy. ok. with ecm unplugged, and the relay unplugged, i had 12v only at the black and white relay wires. (1 and 2 in previous diagrams.) I then plugged in the relay and backprobed my blue/black wire with the ecm still unplugged. I now have 12v in the pin 47 blue/black wire. Next, i unplugged the relay and carefully plugged in the ecm. now when i probed pin 47 wire, i got zero volts. so the 12v is coming TO the ecm when the relay is plugged in. I got this same result with 2 different relays. as far as wire color, the wires came out of the 91 donor harness, so possibly this explains the difference. my other 93 harness has the same wires as the 91. so, now i have a new ecm, and i'd like to plug it in and check my disty wire voltages. Dare i do this with 12v going to the ecm through pin 47? hope you see this post today, you're help is invaluable dude . Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 yo sorry for the yelling but I am so desperate to get this car running.. its been almost 2 weeks out of commision and i'm going insane...read my spfi swap thread (The last pages) for the details.. but the short story is: got a new computer because i fried the old one. have been told by Gloyale that pin 47 ecm should not have 12v running down it new computer is in and working, but can i put in the fuel pump relay, which causes pin 47 to energise? i NEED this car to run! i'm 11 DAYS LATE FOR WORK! Quote Link to comment Share on other sites More sharing options...
jonas Posted May 27, 2007 Share Posted May 27, 2007 EA82 SPFI conversion manual by Snowman maybe this will help? you are probably already using it tho? sry best i can do. also do a search on posts by General Disorder as he seems to be very knowledgeable on this subject and has more than likely covered this topic/question. again i hope this helps. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted May 27, 2007 Share Posted May 27, 2007 pin 47 is the wire that allows the ECU to turn on the fuel pump. with the ECU unplugged, plug in the fuel pump relay, and turn the ignition on. now take a small piece of wire, stick it in pin 47, and touch it to ground. if the fuel pump relay (and therefore the pump itself) comes on, it's wired correctly. Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 ya thanks man but i am following the swap doc carefully. my specific question is " should there be 12v flowing down the blue and black wire to pin 47 and the ecm?" this is what i have. After just now testing my relay again, i think it should, even tho i have been told it shouldnt. BUT i dont want to cook another ECM! Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 ok chux thanks, I was almost there but now i'll check that. Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 27, 2007 Author Share Posted May 27, 2007 alright, i have finally sorted that out now. Thank You Numbchux - pin 47 SHOULD have 12v. now i can move on to trying to fire this thing up FINALLY! :headbang: Quote Link to comment Share on other sites More sharing options...
Gloyale Posted May 27, 2007 Share Posted May 27, 2007 alright, i have finally sorted that out now. Thank You Numbchux - pin 47 SHOULD have 12v. now i can move on to trying to fire this thing up FINALLY! :headbang: This is contrary to all the diagrahms and info in the FSM. Pin 47 activates the relay by supplying ground to the relay. The power for the relay comes from the fusebox through the Black and white wire. Quote Link to comment Share on other sites More sharing options...
Gloyale Posted May 28, 2007 Share Posted May 28, 2007 ahh damn sorry i missed you Gloyale. I was up at the jy. ok. with ecm unplugged, and the relay unplugged, i had 12v only at the black and white relay wires. (1 and 2 in previous diagrams.) I then plugged in the relay and backprobed my blue/black wire with the ecm still unplugged. I now have 12v in the pin 47 blue/black wire. Next, i unplugged the relay and carefully plugged in the ecm. now when i probed pin 47 wire, i got zero volts. so the 12v is coming TO the ecm when the relay is plugged in. I got this same result with 2 different relays. as far as wire color, the wires came out of the 91 donor harness, so possibly this explains the difference. my other 93 harness has the same wires as the 91. so, now i have a new ecm, and i'd like to plug it in and check my disty wire voltages. Dare i do this with 12v going to the ecm through pin 47? hope you see this post today, you're help is invaluable dude . I think your're relay or you're wiring are mixed up. Does the other wire, Blue/white get any voltage. What about when you ground the blue/black wire(unpplugged from ECU) That is supposed to be the wire that recieves voltage from the relay and powers the pump. Pin 47 provides a ground. shouldn't get power Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 28, 2007 Author Share Posted May 28, 2007 well, i dont know what to say dude, it does provide ground as far as i can tell. when i ground pin 47 (while unplugged from the ecm), the relay snaps shut and power is provided to the blue and white wire. so the grounding switch is inside the box . My fuel pump is cycling normally now, so i'm happy. thanks though, i was getting absolutely nowhere until you started giving me some info to work with.. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 28, 2007 Share Posted May 28, 2007 If pin 47 is the connection for providing a ground to the pump then there could be a problem internally with the ECU. It provides the ground by using a switched transistor. If there is a problem with that circuit then you could see voltage there. I have repaired a few ECUs with this very problem in the past. Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 28, 2007 Share Posted May 28, 2007 Pin 47 is a switched transistor circuit that is controlled by the ECU. When the fuel pump is supposed to turn on then the output transistor is turned on and pin 47 ties to ground, turning on the pump. When the circuit is off then the output will go high and you will see a voltage on pin 47 and the pump will turn off. One thing to note. If the ECU doesn't see firing pulses from the ignition system it will keep the pump circuit turned off. The plugs must be firing for the pump to work. The voltage will be high at pin 47 if the ignition system isn't working. Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 28, 2007 Author Share Posted May 28, 2007 yeah cougar thats what i have - high voltage at pin 47. when my green connectors are plugged in the pump cycles on and off like it should. so now i have to go back and figure out why i've got no spark. my disty power wire now reads 12v with the new ecm, and when i slow crank the engine i get 5v pulses from the 2 signal wires (like gloyale was saying to check). so why no spark ? next. can someone confirm which fuel lines are which for me? its been so long since i took the damn carb manifold off that i dont know which is which anymore. when i got the fuel pump running, the steel line that runs along the dr. side frame rail started spewing gas . I thought that the larger line up by the wiper motor was supply... now i'm not sure of any of them. ok cheers, thats it for now. Quote Link to comment Share on other sites More sharing options...
daeron Posted May 28, 2007 Share Posted May 28, 2007 snowman didnt write the conversion to SPFI, GeneralDisorder did. Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 28, 2007 Author Share Posted May 28, 2007 on to pin 52 now... so i gots no spark. my guess is the ignition amplifier. I have 12v up to it in the black and white wire, and 12v on the coil (which was running my car before the swap). but heres the thing. i tested the w/y wire (pin 52) while the car was being cranked, and it showed no signal from the ecm. Is there supposed to be a voltage pulse in this wire? my new ecm seems to be operating normally (test connectors make the fuel pump cycle), but i know nothing about them and have no FSM. i shined up the metal under the coil bracket ok, done for the night. Quote Link to comment Share on other sites More sharing options...
Numbchux Posted May 28, 2007 Share Posted May 28, 2007 snowman didnt write the conversion to SPFI, GeneralDisorder did. snowman wrote it for EA82s years ago. GD wrote one specific to EA81s just within the last 6 months or so. if you test pin 47 with a test light to ground, it will light. it doesn't supply power to the ECU, but if it's connected to a ground, it will complete the circuit (which will activate the fuel pump circuit). I'm looking at a FSM diagram right now, the wire gets power from the other side of the relay. as for the no spark issue. double check your ignition timing. it's real easy to have your disty rotor 180* off, lining up with TDC of the wrong stroke. or are you getting no spark at all? check for trouble codes, it could be the crank angle sensor (which will throw a code). Quote Link to comment Share on other sites More sharing options...
matts87glsedan Posted May 28, 2007 Author Share Posted May 28, 2007 no spark at all. everythings got power, but still no spark. Quote Link to comment Share on other sites More sharing options...
Skip Posted May 28, 2007 Share Posted May 28, 2007 is the coil backet with the amplifier transistor grounded? Quote Link to comment Share on other sites More sharing options...
Cougar Posted May 28, 2007 Share Posted May 28, 2007 First check for any error codes. If you don't have a error code for the CAS in the disty then it would appear that it is ok and the trouble may be with the ignition amp. Quote Link to comment Share on other sites More sharing options...
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