 Fuel Injection: no negative reading at injectors, Car dies after 2-3 seconds |
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| Stanley1x |
 Mar 27 2016, 12:42 PM
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#1
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Newbie  Group: Members Posts: 3 Joined: 10-June 15 From: san diego, ca Member No.: 18,830 Region Association: None  |
My mechanic states he does not get negative at the fuel injectors (1974 1.8) and the car starts and runs only a couple seconds via the cold start plug.
Any suggestions as to why or where to to locate the problem would be greatly appreciated! Thank you |
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| ClayPerrine |
Mar 29 2016, 11:46 AM
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#2
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Life's been good to me so far..... Group: Admin Posts: 15,523 Joined: 11-September 03 From: Hurst, TX. Member No.: 1,143 Region Association: NineFourteenerVille 
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First off... I would get a new mechanic that actually knows how L-Jet works. From what he is telling you, he doesn't understand the system.
Second, this is L-Jet. It does not use trigger points in the distributor The injectors are fed power from the double relay. That is sent to the dropping resistors and from there to the injectors. The negative side of the injectors are controlled by the ECU (I use that term loosely here). They are pulsed in a batch mode by the white wire that runs from the ECU to the negative side of the coil You should have an Air Flow meter attached to the air filter in the left rear of the engine compartment. It will have a 6 pin (if it is a 74) or a 7 pin (if it is a 75) connector on the rear side, next to the tube for the engine lid release. If this is not hooked up, the injectors will fire during start, but shut down when you release the key back to run. Get a noid light ( Bosch fuel injection test light) from FLAPS. Disconnect an injector lead, and plug it in. Then try to start the car. If the light flashes during cranking but not when you release the key, then either your AFM is unplugged, the harness is broken, or the AFM is bad. I would bet on a problem with the harness. |
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| malcolm2 |
Mar 29 2016, 12:15 PM
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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
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QUOTE(ClayPerrine @ Mar 29 2016, 12:46 PM)  Get a noid light ( Bosch fuel injection test light) from FLAPS. Disconnect an injector lead, and plug it in. Then try to start the car. If the light flashes during cranking but not when you release the key, then either your AFM is unplugged, the harness is broken, or the AFM is bad. example of noid lights The auto parts store will loan (rent) them to you... basically free to use once returned. there are so many choices cause you can use them on just about any FI system. You only need the one little noid that fits your injector electric connection. With these guys chiming in, you don't need a mechanic at all. If you can do what they suggest, and have a voltmeter.... (IMG:style_emoticons/default/confused24.gif) you will be running before the weekend. |
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Posts in this topic
Stanley1x Fuel Injection: no negative reading at injectors Mar 27 2016, 12:42 PM
Jeff Bowlsby What negative are you speaking about? Do you have... Mar 27 2016, 12:49 PM stugray "What negative are you speaking about?"
... Mar 27 2016, 02:20 PM r_towle All the injectors are grounded at a common ground ... Mar 27 2016, 03:55 PM timothy_nd28 If the car runs for a few seconds, I would turn my... Mar 27 2016, 04:54 PM phatnine11 As mentioned, check your grounds and the trigger p... Mar 27 2016, 05:01 PM timothy_nd28 Actually, the ignition points are the trigger poin... Mar 27 2016, 05:08 PM
phatnine11
Actually, the ignition points are the trigger poi... Mar 27 2016, 05:46 PM jim_hoyland Whenever my 1.8 L-Jet only runs a few seconds it b... Mar 27 2016, 05:13 PM timothy_nd28 Ljets do not have a fuel trigger points under the ... Mar 27 2016, 07:03 PM Stanley1x Thank you for your responses everyone. For clairi... Mar 29 2016, 11:26 AM malcolm2
Thank you for your responses everyone. For clair... Mar 29 2016, 12:37 PM timothy_nd28 I do agree with finding a new mechanic that's ... Mar 29 2016, 01:53 PM Mueller ^in layman's term: when the coil "collaps... Mar 29 2016, 03:52 PM timothy_nd28 You forgot to mention turn signal blinker fluid :... Mar 29 2016, 04:53 PM Stanley1x Thank you again everyone for your salient response... Mar 30 2016, 12:58 PM Jeff Bowlsby Have you reviewed the component testing procedures... Mar 30 2016, 01:13 PM timothy_nd28 Do you own a multimeter and is the car back in you... Mar 30 2016, 02:10 PM |
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