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please help me im a new owner and my fuel injectors arn't getting any ground?


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im a new owner im 17 years old and love my car but she wont get any ground to the fuel injectors I have new fuel pump and fuel injectors the fuel gets to the injectors but can not pass through them I have 12 volts just no ground please help! I have a 1987 Chrysler conquest 5 speed. Edited by MIDNIGHT.EMPIRE.CONQUEST87
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ok. how are you testing for ground signal? (what process are you using? you should be using a small fuel injector noid light to get an accurate idea)

 

the ground signal is provided by the ECU, based on the timing it receives from the distributor and the pulse width it determined based on the MAF and TPS sensors.

 

are you still getting spark to the spark plugs?

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ok. you need to check for injector ground WHILE THE ENGINE IS CRANKING. the injectors only get a ground when the engine is spinning.

 

let us know what you find. if no ground during cranking it could be a break in the harness or could be faulty ECU.

 

this is gonna take time btw. troubleshooting over the internet is a pain.

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ok thanks and no still no ground and someone has messed with the harness coming out the top of the ecu so idk if its rite or not it had a super airflow converter on it but I took it off he had wires cut everywere I hooked them back up but idk there is a odd big brown wire with a whit wire inside of it and idk ?
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dude, you're gonna have to find the fuel injection wiring harness, print it out, and put the wires where they are suppose to be.

 

page 45 has the section that shows the injectors, but you'll need to print out the couple of pages before and after and tape the pages together to get a diagram.

 

http://www.starquestgarage.com/manuals/service/conquest/1988/88_conquest_service_manual_-_group_14_-_fuel_system.pdf

 

it's for a 1988 not and 1987 but it's all that I could find. hopefully the colors are the same. take a picture of the wires at the ECU if you can, and hook as many up as you can.

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There are two shielded white wires going to the ecu, one is the o2 sensor signal and the other is the signal from the negative side of the coil that tells the ecu the engine is turning over. Without that signal the ecu won't even try to fire the injectors, from your description I suspect this is your problem. Is this wire on one end of the yellow connector? That would be what the factory calls position 1. Download a wiring diagram from www.starquestgarage.com and review the ecu section.
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brown shielding?? the "shielding" is a wire mesh that goes around the main signal wire. it's there to prevent signal interference.

 

http://product-images.highwire.com/778542/1025303.jpg

 

 

so when you say "brown wire shielding" that doesn't make any sense, because as far as I remember the only wires that have shielding are two white wires.

 

 

 

 

you're going to have to do a continuity test. first make sure the wires from the ECU to the injectors aren't broken somewhere. What type of multimeter do you have? does it have an Ohm meter on it??

 

and TAKE A PICTURE of the wires at the ECU so you can show us what you're talking about.

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if all the wires are still there and traceable to their original place, it would be much much easier to just some new wires spliced in place & solder an repairs need rather than installing a full harness.

 

don't give up. just take each wire one at a time, figure out where it's suppose to go (based on the wiring diagram) and then make sure it's connected the whole way etc etc. takes some time but it's step 1 since your set up is pretty messed up.

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I think I got them all hooked up right I just don't know what sensor is bad causing my fuel injectors to not get any ground. if u guys know what sensors control fuel injection ground please tell me ill do anything to test it or scrounge up money to buy a new one. I need to get my car running soon so I can get it tittled. thanks
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you shouldn't be using test lights to test ANYTHING on a fuel injector system, as a general rule. the electrical draw for a lightbulb can be higher than what the system is designed for.

 

use a multimeter.

 

plus a test light won't let you know how much voltage you're getting. a bulb could light up for many different voltages.

 

The ECU get's it signal from the pick-up inside the distributor. so look at the diagram and see what goes from the dist to the ECU and see if there is a signal pulse going in to the ECU.

 

the ECU needs to see an RPM signal to determine the pace at which the injectors fire. then it needs a load signal so it knows how long to open the injectors, this would be generated by the MAF sensor, which sends out a Hz signal.

 

which, unless you have a highend multimeter you're not going to be able to test for Hz

 

so, at a minimum, you're gonna have to see if the ECU is getting a signal from the distributor.

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