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fuel system something???


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yamaha221
Novice

Mar 13, 2012, 3:03 PM

Post #1 of 12 (1812 views)
fuel system something??? Sign In

1999 s10 2.2 190,000....i came home from work on a lunch break shut it off for about 20 min and when i went to go back to work it started fine and put it in reverse started to move it died hasnt started since. (i cut a hole in the bed of the truck) i have checked the 2 fuses, swapped out the relay with multiple others and did a test with the little wires coming up from the relay, every thing is good. i have also got a new fuel pump, fuel filter and made a new ground in the rear, then i also tried the ground straight off the pump by cutting it 2in down and grounded it on the fresh metal from the hole. there is power to grey wire in the harness at the fuel pump and when its cranked over the other wire has a dim light(i dont know if its supposed to be dim or not)...it cranks over fine and will run if there is gas sprayed in the throttle body. PLEASE HELP i have been working on and talking to people since fri....


Hammer Time
Ultimate Carjunky / Moderator
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Mar 13, 2012, 4:26 PM

Post #2 of 12 (1788 views)
Re: fuel system something??? Sign In

 All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



nickwarner
Veteran / Moderator
nickwarner profile image

Mar 13, 2012, 5:38 PM

Post #3 of 12 (1771 views)
Re: fuel system something??? Sign In

I deleted your other question. Please don't post duplicates. Just gets everyone confused and slows down the process.


yamaha221
Novice

Mar 13, 2012, 5:48 PM

Post #4 of 12 (1767 views)
Re: fuel system something??? Sign In

sorry...will a fuel pump work conected to the battery and not the harness if its bad?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 13, 2012, 5:52 PM

Post #5 of 12 (1759 views)
Re: fuel system something??? Sign In

Well, of course not if the pump is no good.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



yamaha221
Novice

Mar 13, 2012, 5:57 PM

Post #6 of 12 (1754 views)
Re: fuel system something??? Sign In

if the tester shows that i have power in the harness plug but the pump wont turn on when the key is turned on. no click or anything


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 13, 2012, 6:01 PM

Post #7 of 12 (1751 views)
Re: fuel system something??? Sign In

You can test it with a battery but it sounds like a bad pump assuming the ground is OK.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



yamaha221
Novice

Mar 13, 2012, 6:09 PM

Post #8 of 12 (1747 views)
Re: fuel system something??? Sign In

both the new pump and the old one work connected to the battery but not hooked to the harness


Hammer Time
Ultimate Carjunky / Moderator
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Mar 13, 2012, 6:11 PM

Post #9 of 12 (1745 views)
Re: fuel system something??? Sign In

Then you obviously have a problem with the harness. If you have confirmed powerat the connector, check the ground wire.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



yamaha221
Novice

Mar 13, 2012, 6:53 PM

Post #10 of 12 (1738 views)
Re: fuel system something??? Sign In

i've even cut the ground wire 2 inches from the connector and re grounded it to the bed..is it possible that there isnt enough power going back there


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Mar 13, 2012, 6:59 PM

Post #11 of 12 (1734 views)
Re: fuel system something??? Sign In

You're the one measuring it, is there?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
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Mar 13, 2012, 7:52 PM

Post #12 of 12 (1705 views)
Re: fuel system something??? Sign In

You might have 12 volts sitting at the end of the connector with it unplugged, but if you have a excessive resistance in the wiring or connectors somewhere, your going to drop voltage before getting to the pump when the circuit is operating.

You need to do a voltage drop test of the wiring with the circuit active. Voltage drop tests not only works on starting circuits, but any electrical circuit. The only part of the circuit that should be dropping voltage is the fuel pump itself. Normally you shouldn't see more the .030 VDC drop in any part of the circuit except for the load itself. If you have high resistance in a connector, relay contact, and/or parts of the wiring, you have a problem. Remember resistance adds up in a series circuit. The more resistance the less current that passes through. Not enough current and the load won't operate.

Just pretend the light bulb in the circuit is the fuel pump. Notice the circuit has to be powered up and you have to back probe connections to connect your meter:







Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Mar 13, 2012, 7:54 PM)






 
 
 






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