75 LJet will not fire, finishing restoration |
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75 LJet will not fire, finishing restoration |
malcolm2 |
Jun 28 2013, 10:45 PM
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#1
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
Ok I think I am good on the seat belt relay. YLW and YLW/red are spliced. And I have checked for continuity all the way from the starter to the key on that wire.
I have spark, points checked too. I have fuel pressure, about 40 psi, checked between p-side fuel rail and cold start valve. Starter works fine oil pressure builds, light goes out on the dash Engine timing is still at rebuild setting...0 TDC. Re-built FI & Ignition & Alt harnesses I did have trouble with the key switch, so the steering wheel is out, levers are not connected and I turn a screw driver on the end of the key connector to fire the starter, should not be an issue, correct? I got the L-jet trouble shooting "no start" pages to try tomorrow. Any other ideas? I am baffled. (IMG:style_emoticons/default/confused24.gif) |
timothy_nd28 |
Jun 28 2013, 11:58 PM
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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 |
Can you post a few pics, so we can rule out anything obvious
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malcolm2 |
Jun 29 2013, 07:05 AM
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#3
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
Can you post a few pics, so we can rule out anything obvious anything specific you would like to see? I'll snap a few of the items I mentioned. The Rats nest that is the seat belt relay, mostly. YLW and YLW/red are spliced. Anything else of concern here? fuel pressure gauge (temporary) between the pass. fuel rail and the CSV. going down quickly after 2 15 seconds tries at starting. coil and connections Top of engine shot. Relay plate, uncovered. no steering wheel, control levers, key switch. turning the switch with a std screwdriver. I can take additional shots, just let me know what. Thanks, Clark |
jim_hoyland |
Jun 29 2013, 07:21 AM
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#4
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Get that VIN ? Group: Members Posts: 9,558 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
My favorite no-start issues have been:
1. Yellow wire at rear of harness not connected to the 4 spade plug 2. Black ignition wire on negative side of coil 3. The 6-pin plug that goes into the AFM is unplugged or loose 4. The ground wire from the dual relay is not connected, it goes onto a spade in the middle of the engine case 5. White FI wire,along with tach wire, not on the negative terminal of coil 6. Lastly, a bad connection at the + battery of one of the red wires. Two reds go to the 14 pin connected at thr front of the relay board. Good luck, been there; tell us what you find out |
timothy_nd28 |
Jun 29 2013, 09:33 AM
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#5
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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 |
Okay, so the car turns over and you already verified spark and fuel pressure. I would double check and make sure you have the dropping resistors for the fuel injectors connected. Then turn your attention to the dual relay. With the ignition switch turned to the "on" position, measure pin 88a for voltage. You should see 12vdc, if this is true, remove the ECU connector and measure pin 10 for 12vdc.
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Rockaria |
Jun 29 2013, 09:53 AM
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#6
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ZippidyDoDah... Group: Members Posts: 817 Joined: 2-May 03 From: Southwest, USA Member No.: 645 Region Association: None |
My favorite no-start issues have been: ... 3. The 6-pin plug that goes into the AFM is unplugged or loose ... Done this before... A few times.... So embarrassing (IMG:style_emoticons/default/dry.gif) Harder to admit! My final solution, sell the 75 and buy a 73. All better. Also check the resistor pack (The 4 cigaretts in a metal sleeve) they can come loose. (not only the connector... inside at the white parts, the connection can break.) |
jim_hoyland |
Jun 29 2013, 10:13 AM
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#7
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Get that VIN ? Group: Members Posts: 9,558 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
Another thing I would ask: Does the engine start for a second or two and then stop, or does it not start at all.
Your fuel pressure gauge indicates that the dual relay is working. When there is a lose DR wire or the DR is cooked, the fuel pressure gauge reads zero |
malcolm2 |
Jun 29 2013, 11:59 AM
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#8
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
Morning tests lead me to the Injectors. I pulled the electric connection from one injector and put the meter on the connections and tried to start the car. Got no reading on the meter. Checked continuity from the ECU to that injector and both wires are sound. BOWLSBY did all my harnesses.
Earlier question: ever start? No never fired at all, no gas on the plugs. |
timothy_nd28 |
Jun 29 2013, 12:01 PM
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#9
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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 |
Did you have 12vdc on pin 10 on the ECU connector?
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timothy_nd28 |
Jun 29 2013, 12:10 PM
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#10
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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 |
If you don't have 12v at pin 10 you won't have voltage at pins 14,15,32 and 33 either. Run a temp jumper on the dual relay pin 88a to the positive battery post and try starting the car.
BTW, You won't have much luck reading voltages at the fuel injector connector. The voltage will be a quick blip and most modern multimeters won't measure it. Unless you're using an analog meter, this would allow you to see the meter needle sweep back and forth. |
jim_hoyland |
Jun 29 2013, 01:26 PM
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#11
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Get that VIN ? Group: Members Posts: 9,558 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
I assume the resister pack is plugged in; you may want to test the dual relay at the resister terminal, see diagram below. With the key on the ircuit to the resisters should be hot. Diagram is a Top view...
Attached image(s) |
Sleepin |
Jun 29 2013, 01:37 PM
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#12
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Advanced Member Group: Members Posts: 3,647 Joined: 20-November 07 From: Grand Junction, Co. Member No.: 8,357 Region Association: Rocky Mountains |
Every time mine hasn't started (each time in the garage without any work done on it), I scream and cuss at it....walk away...curse at it every time that I walk past it for a few days...
Then when I try it again a few days later, she fires right up. No BS...this has happened more than twice. |
malcolm2 |
Jun 29 2013, 02:04 PM
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#13
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
Okay, so the car turns over and you already verified spark and fuel pressure. I would double check and make sure you have the dropping resistors for the fuel injectors connected. Then turn your attention to the dual relay. With the ignition switch turned to the "on" position, measure pin 88a for voltage. You should see 12vdc, if this is true, remove the ECU connector and measure pin 10 for 12vdc. Yes 12v at both. FOr those following or future problems.... page two of this link has the pin out for the ECU of the L-jet. Bowlsby's L-Jet FI harness |
malcolm2 |
Jun 29 2013, 02:10 PM
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#14
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
BTW, You won't have much luck reading voltages at the fuel injector connector. The voltage will be a quick blip and most modern multimeters won't measure it. Unless you're using an analog meter, this would allow you to see the meter needle sweep back and forth. That is what I thought might happen. My meter is digital. |
timothy_nd28 |
Jun 29 2013, 02:16 PM
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#15
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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 |
Good, now with the ECU connector off, measure pins 14,15,32,33 You should have 12volts on those as well
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malcolm2 |
Jun 29 2013, 02:16 PM
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#16
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
If you don't have 12v at pin 10 you won't have voltage at pins 14,15,32 and 33 either. Run a temp jumper on the dual relay pin 88a to the positive battery post and try starting the car. Since I have voltage at 88a, there is no since in jumping here, correct? I have voltage at 10 too. |
timothy_nd28 |
Jun 29 2013, 02:19 PM
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#17
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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 |
If you don't have 12v at pin 10 you won't have voltage at pins 14,15,32 and 33 either. Run a temp jumper on the dual relay pin 88a to the positive battery post and try starting the car. Since I have voltage at 88a, there is no since in jumping here, correct? I have voltage at 10 too. correct, it would be redundant. Check those pins on the ECU connector that I described above. |
malcolm2 |
Jun 29 2013, 02:20 PM
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#18
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
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timothy_nd28 |
Jun 29 2013, 02:52 PM
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#19
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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 |
I'm not home, give me a hour to reply
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malcolm2 |
Jun 29 2013, 02:55 PM
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#20
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Advanced Member Group: Members Posts: 2,747 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
I'm not home, give me a hour to reply ANY & ALL help is appreciated. I feel like I have tried everything! And everything is fresh and new, but still nuttin'! (IMG:style_emoticons/default/screwy.gif) (IMG:style_emoticons/default/confused24.gif) |
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