1.8 l-jet fires, but dies within seconds, tried searching :-/ |
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1.8 l-jet fires, but dies within seconds, tried searching :-/ |
thatguywiththedatsun |
Mar 21 2014, 01:36 PM
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#1
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Newbie Group: Members Posts: 21 Joined: 21-March 14 From: Memphis, TN Member No.: 17,144 Region Association: None |
I've been looking for a 914 for a few months now, but life has been in the way. I found one last month that seems to be a good starting point, but I'm having trouble getting it to stay running atm. Seems like it's probably the l-jet system being out of adjustment or leaky, faulty sensors, or some old corroded electrical connectors. The question is; where?
I'm getting a buzzing sound with the key turned to "on" which I initially thought was the seatbelt interlock buzzer everyone seems to be so fond of, but upon closer inspection... it's coming from the injectors..? If i unplug the noisy injector, another one starts buzzing. There's no noise from the fuel pump at this time with the key on. The fuel pump relay, and power supply relay on the board were nowhere to be found when I got the car. I went ahead and bought a few new ones to get it back to stock wiring, but I'm really having trouble deciphering the current flow diagrams. (You guys seems to have a reference system to the pins in every connector, or which specific relay you're referencing. Is there a diagram for this somewhere, or are the labels just buried under the grime in this car?) If i hot wire the double relay (86d, 88d?) to the + battery post, the fuel pump will run, but this doesn't change my "start, rumble rumble, die" situation at all. I have a feeling that there is an area in the wiring that has been altered which, if put back to stock, would rectify the problems I'm having... It's just a matter of finding it and fixing it. Any suggestions? What I have done: -compression test: 125,130,90,135 - hoping it will improve pending a valve adjustment? -tested the coil and wires for spark - checks out fine... nice and strong -tested fuel pressure - 43psi holding steady for several minutes after the test (p.o. said he'd recently had the fuel pump replaced, but didn't mention why (IMG:style_emoticons/default/dry.gif) ) -renewed all the l-jet vacuum hoses and put hose clamps on every connection -taken care of a few obvious electrical bugs (missing/rusty relays, broken wires, etc) -checked the head temp sensor spade connection, but where does the other end of that connection terminate on the relay board? -checked afm resistance. - With key on, if I move the flap by hand, the fuel pump does run, but there is no 1.5 seconds of priming with the key on, just the annoying injector buzz. Thanks in advance for the help! I'll be much better off if someone could just explain the 'pin 13/relay 74/etc. references to me. (IMG:http://www.914world.com/bbs2/uploads_offsite/lh5.googleusercontent.com-17144-1395430598.1.JPG) (IMG:http://www.914world.com/bbs2/uploads_offsite/lh5.googleusercontent.com-17144-1395430599.2.JPG) (IMG:http://www.914world.com/bbs2/uploads_offsite/lh3.googleusercontent.com-17144-1395430600.3.JPG) (IMG:http://www.914world.com/bbs2/uploads_offsite/lh3.googleusercontent.com-17144-1395430600.4.JPG) |
timothy_nd28 |
Mar 23 2014, 09:30 AM
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#2
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Advanced Member Group: Members Posts: 2,299 Joined: 25-September 07 From: IN Member No.: 8,154 Region Association: Upper MidWest |
Great, just wanted to verify that you weren't still in the meg ohm range. I'll assume that you were getting a solid 12volts on pins 14-15-32 and 33?
Never mind the dual relay at the moment. The fact that it turns on the fuel pump when you deflect the AFM flap tells me that it is wired correctly. Also your car does start briefly also says that you have fuel pressure when cranking. Lets do a few more test. With the ECU plug pulled and the ignition switch at the "off" position, put one meter lead on the +12vdc battery post and the other meter lead on pins 5,16 and 17. The meter should read 12 volts on each pin. After this, remove all fuel injectors from the manifold and insert into glass jars. Turn the ignition switch to the "on" position. Jump pin 88d to +12vdc on the battery post. Use one of your meter leads (detached from the multimeter) and find a way to ground one side of this cable to the negative side of the battery. With the pointy end of the meter lead, insert into pins 14,15,32 and 33. You should hear an audible click (no buzzing), you should also see one of the injectors spraying. Observe the spray pattern while the FI is engaged and be sure it fully shuts off when the meter lead is removed from its corresponding pin. Do this for all 4 injectors. Make sure only one injector is spraying when doing this test, that others are not simultaneously spraying. |
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