Fuel Injection woes |
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Fuel Injection woes |
G e o r g e |
Nov 12 2007, 03:14 PM
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#1
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
OK
here my problem, I'm trying to use my previously functioning L jet system to break in my fresh rebuild, before i switch to an sds system. fyi I had removed everything from the engine bay for paint so everything is a fresh reinstall. which I'm sure is where my problem lies. I have spark, compression and fuel pressure, but no fuel coming from my injectors. I have checked my wiring over and over, and believe i am correct. I ,for the sake of argument, am a neophyte at best when it comes to this so any and all direction is appreciated. my ??? what causes the injectors not to fire ? is there a spot on the net that actually shows ( pics, diagrams)of the fuel injection harness connections? Where do I begin to test to get this system up and running? I would switch to sds, but the switch will be easier with the engine timed and able to idle as i work out the initial bugs. |
ejm |
Nov 12 2007, 03:44 PM
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#2
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I can see the light at the end of the tunnel Group: Members Posts: 2,695 Joined: 3-February 03 From: Massachusetts Member No.: 224 Region Association: None |
QUOTE what causes the injectors not to fire ? The single white wire from the FI harness to terminal 1 on the coil is a must have.... |
Brando |
Nov 12 2007, 03:47 PM
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#3
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BUY MY SPARE KIDNEY!!! Group: Members Posts: 3,935 Joined: 29-August 04 From: Santa Ana, CA Member No.: 2,648 Region Association: Southern California |
What kind of ignition system are you running?
In stock configuration the injection system recieves it's RPM info and trigger from the points in your distributor. Without the high voltage pulse from the points it will not trigger. Now, there are ways you can trick it into working. IE: On MSD setups your run a stand-alone coil that runs in-line with the ignition switch lead tot he points and trigger wire for the ECU. If you're using a stockish (read: 035, 009, etc) distributor with the magnetic pickup, you can still attach it to the coil negative lead and it will work. Now... Do you have all your wiring hooked up correctly? Is the Air Flow Sensor hooked up correctly? Do you have any large vacuum leaks? Is the ECU recieving voltage appropriately? If you are running a stock distributor with points, is your timing and dwell set correctly? All of these things make or break L-Jet working properly. Check and report back to us (IMG:style_emoticons/default/smile.gif) |
G e o r g e |
Nov 12 2007, 04:46 PM
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#4
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
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G e o r g e |
Nov 12 2007, 04:54 PM
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#5
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
What kind of ignition system are you running? mallory QUOTE Do you have all your wiring hooked up correctly? I believe so.. QUOTE Is the Air Flow Sensor hooked up correctly? I believe so QUOTE Do you have any large vacuum leaks? fresh (new) tight hoses everywhere QUOTE Is the ECU recieving voltage appropriately? I will check voltage when i get home QUOTE If you are running a stock distributor with points, is your timing and dwell set correctly? timing should be in the ball park to get her started |
Cap'n Krusty |
Nov 12 2007, 04:58 PM
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#6
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
Double relay there and functional? Yellow wire plugged in to the correct tab in the relay board? The Cap'n
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jim_hoyland |
Nov 12 2007, 05:01 PM
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#7
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Get that VIN ? Group: Members Posts: 9,320 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
George,
Is the yellow wire attached to the relay board ? I assume you put gas in the tank?? Attached image(s) |
Brando |
Nov 12 2007, 05:20 PM
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#8
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BUY MY SPARE KIDNEY!!! Group: Members Posts: 3,935 Joined: 29-August 04 From: Santa Ana, CA Member No.: 2,648 Region Association: Southern California |
George, can you please elaborate on your Mallory ignition?
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SLITS |
Nov 12 2007, 06:22 PM
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#9
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
Resistor pack installed with no broken wires?
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G e o r g e |
Nov 13 2007, 12:07 AM
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#10
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
yes to the yellow wire to proper location yes to fuel ( boiled tank all new lines ) resistor pack all wires are connected double relay installed, unable to prove functional have another relay that I'm picking up at my shop now to swap out and see I've been using the search function most of the evening and reading the many sites or pages that the captain has recommended before.and i can see that i need to expand my electrical testing tools so i have decided if this doesn't work ( swapping out the relay) then I might as well just pull all of the L jet and install the sds system that i planned on using in the long run Brando , Mallory unilite and original coil at this moment. I will be swapping out the coil with promaster E coil and the Mallory ballast resistor during the sds install. |
G e o r g e |
Nov 13 2007, 12:09 AM
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#11
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
Neophyte ???,
but where do i check the ecu voltage? |
Brando |
Nov 13 2007, 01:16 PM
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#12
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BUY MY SPARE KIDNEY!!! Group: Members Posts: 3,935 Joined: 29-August 04 From: Santa Ana, CA Member No.: 2,648 Region Association: Southern California |
I was asking if it was getting power. 12V trigger lead, Yellow wire on the engine bay fusepanel.
It should be working if everything is hooked up correctly. Could be a bad ecu? When was the last time this system was installed and working properly? |
JeffBowlsby |
Nov 13 2007, 04:13 PM
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#13
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914 Wiring Harnesses Group: Members Posts: 8,535 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
Here is a link to an L-Jet manual.
http://members.rennlist.com/914_collectibles/zRareDoc06.pdf And here is a link to a draft L-Jet wiring harness diagram. I have better drawings, but they are not on the website yet: http://members.rennlist.com/914_wiring_harnesses/ (IMG:style_emoticons/default/flag.gif) |
JeffBowlsby |
Nov 13 2007, 07:27 PM
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#14
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914 Wiring Harnesses Group: Members Posts: 8,535 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
I deleted this post...answered my own question
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G e o r g e |
Nov 14 2007, 12:36 AM
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#15
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
well the first problem has been found
broken and frayed wires going to TTS wires under rubber boot where broken Brando, it has been a about a year since the system was in use, but it did work fine but heck the PO said he had the engine rebuilt, i do believe he had the engine worked on because i had to replace the case from where a rod had punctured it anyways everything keeps directing me to install the sds and go from there I have another harness, but i believe it is from a 75 off the top of your heads is this going to be compatible? thanks for the links |
JeffBowlsby |
Nov 14 2007, 12:47 AM
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#16
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914 Wiring Harnesses Group: Members Posts: 8,535 Joined: 7-January 03 From: San Ramon CA Member No.: 104 Region Association: None |
I have another harness, but i believe it is from a 75 off the top of your heads is this going to be compatible? The 74 and 75 harnesses and ECUs and AFMs were different and not compatible. Check to see if the AFM connector on your harness has the same number of contacts as your AFM. |
G e o r g e |
Nov 14 2007, 12:57 AM
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#17
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Dr Group: Members Posts: 1,905 Joined: 20-September 05 From: Southern Cal Member No.: 4,832 Region Association: None |
The 74 and 75 harnesses and ECUs and AFMs were different and not compatible. Check to see if the AFM connector on your harness has the same number of contacts as your AFM. (IMG:style_emoticons/default/chair.gif) I don't know why I even asked that I have read that a hundred times on here |
jim_hoyland |
Nov 14 2007, 08:53 AM
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#18
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Get that VIN ? Group: Members Posts: 9,320 Joined: 1-May 03 From: Sunset Beach, CA Member No.: 643 Region Association: Southern California |
(IMG:style_emoticons/default/popcorn[1].gif) Any Update ?
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slackin' at work |
Nov 14 2007, 09:42 AM
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#19
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i should be working Group: Members Posts: 265 Joined: 12-October 07 From: charlottesville, va Member No.: 8,215 Region Association: MidAtlantic Region |
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sunnyvale |
Nov 14 2007, 11:51 AM
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#20
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Newbie Group: Members Posts: 3 Joined: 2-October 07 From: Manchester Member No.: 8,177 |
Check the cylinder head temp sender isn't open circuit.
Ground the sender wire if so, add a 2k or 3k ohm resistor depending on how cold it is. |
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