Ok....need help asap!

Alright, so what started out as a simple spark plug change has "domino'd" into the unknown.

Spark plugs were fouled, so I changed them. Go to crank the engine and nothing. Just turns over but no ignition.
So I check to see if I'm getting spark, I am.
I check the fuel rails and I had no fuel pressure, so I changed the fuel filter and still nothing.

Turns out my fuel pump isn't priming or sending out any fuel. So it must be the fuel pump has been shot.

So I order a new fuel pump and proceed to change it out. Same problem....fuel pump is brand new but doesn't primer itself or send out fuel after everything's been reconnected and trying to start the engine.

All of my fuses are good, both under the hood and inside the car, by the door panel. Battery is good and everything else turns on.

My only thing is wondering if there is a wire that has been snipped or something and has cut off power to the fuel pump. :thinkin:

Extra info:
this started up after we had consistent days of rain throughout here in Lubbock and happened after I came home from work, driving through the rain. So maybe something got wet? But it's been REALLY hot the past 2 days and have thoroughly let it sit in the sun and dry everything out.

Noticed my Service Engine light is on, NOT the Service Engine Soon light BUT the Service Engine light, located by the lower left of the Tachometer.

change the pump or the sending unit and pump? the sending unit fails instead of the pump sometimes

Check to see if you're getting voltage to the pump. I would also check the ground wire, if it doesn't have a good ground it won't work.

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Originally Posted by Knight

Check to see if you're getting voltage to the pump. I would also check the ground wire, if it doesn't have a good ground it won't work.

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x2 on the ground i did one on an s10 and the ground for the tail lights was undone and it still made the pump not come on

check pump relays also.

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Originally Posted by Knight

Check to see if you're getting voltage to the pump. I would also check the ground wire, if it doesn't have a good ground it won't work.

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X2 You might have broken it off

Yepp, sounds like your not getting power to your pump, ensure your relay is good and functioning, also check your grounds and since your were in the engine bay, take a look around at anything you could have bumped or knocked loose, IE Wiring harness going into computer.
J

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Originally Posted by garygnu65

check pump relays also.

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Originally Posted by sunsetorangess

Yepp, sounds like your not getting power to your pump, ensure your relay is good and functioning, also check your grounds and since your were in the engine bay, take a look around at anything you could have bumped or knocked loose, IE Wiring harness going into computer.
J

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what these guys said.....start with checking for 12volts at the pump. Do you hear the pump come on and try to prime or is it not coming on at all? If not at all I doubt it's getting voltage so I'd start by swapping that relay around with a fan relay or something and try to get it to prime.

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Originally Posted by SajoR

Noticed my Service Engine light is on, NOT the Service Engine Soon light BUT the Service Engine light, located by the lower left of the Tachometer.

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Did you mean to say Service Vehicle NOT Service Engine Soon?

May be a dumb (?) but did you remember to plug the harness back in, inside the "hump" behind the rear driver side passenger seat? Also was it the splice in type pump? May have pulled apart putting the tank back in possition.. Just guessing tho..

Sorry Cutlass, yes I meant to say Service Vehicle not Service Engine light......I was in a rush to try and post this up and have barely come back and checked everybody's feedback.

As far as the pump itself goes, it was a whole unit type pump, not the kind you splice in, but the kind that you unplug the wires and hoses, pull out old pump and put in new pump and reconnect everything, which I have gone over several times to ensure they are properly and snuggly connected (they are).

No, the pump does not turn on at all nor make any noise.

I checked relays and fuses, everything is fine, nothing was bumped into or shaken loose like a wiring harness and I am getting power through the fuse/relay boxes.

I checked the ground at the pump and it is also intact and seems to be in good shape.

So I checked the power to see if it's getting any with a voltmeter and it's not. So my next step is going to have to trace back the wiring from the fuel pump all the way back, checking at intervals with my voltmeter to see where the power finally pops up again. Then hopefully, I'll know exactly where the short is or whatever it is that is causing this. :(

If I still can't find anything after that, I may have just received a non-working pump.....

Just sucks cause I have work AND school and have been without a car for over a week now and I hate depending on other people for my transportation. I'll try to get it done tomorrow guys and let you know if I have any luck.

I really want to avoid having to take it to a mechanic mainly because I'm strapped for funds as it is with summer courses and books having just been purchased but I need my vehicle running again.

So anybody else who might have an idea or something for me to check out, let me know please.

Didn't you solve your problem technically? You said that you're not getting power through the wiring, correct? Did you ever hook the pump up directly to a power source when it was out of the car? I think that would be the only way to rule out the fuel pump. But if the pump isn't getting power even a good pump isn't going to help you. Haha.....

your issue here is power related to the pump. You need to really recheck everything including the fuel pump fuse and the relay. You can remove the fuel pump relay and hard wire (simply put a small piece of wire in the terminals) the pump to hear it working but you need to know which wires are the power line. If you hard wire it and you still don't hear it then you have an issue with the wiring and/or ground. If you put a new relay and still don't work after confirming that it works by hard wiring it then you must likely have an issue with the signal going to the fuel pump relay.

Don't get into checking the pump or swaping it again until you get power to the top of the fuel pump. I have a feeling that your old fuel pump is fine.
keep us posted

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Originally Posted by SajoR

Sorry Cutlass, yes I meant to say Service Vehicle not Service Engine light.......

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I figured :D
Do you have any of the connectors that run over the passenger side wheel well unplugged? There are a couple important fuel pump relay wires that run through those. Also the relay ground is on the back of the LH cylinder head. Do you have any reason to suspect any of this stuff?
Also a scan for codes might help also. Post up the code numbers if you get any

Yeah, that's what I figured as well.....but here's the weird part. Ever since the Service Engine light came on and the fuel pump lost power, I've hooked up my OBDII Scanner and it won't connect to the car. It keeps telling me that a connection cannot be established. Like the computer isn't working right?! :thinkin:

I'm going to end up having to call one of my buddies with a LS1 tuner program to see what he can tell me or help me out.

^^^right, could very well be related. Go over all your fuses again, PCMs have more than one, and that could be the whole issue. Find out why the "no communication" for the scanner, usually it is a fuse somewhere. It would help if you had a wiring diagram for engine performance, that would tell you where all the wires go to and where all the fuses are.

Here's a schematic

first thing is to check your cig lighter fuse.....that's the fuse that the OBD 2 port is on.

Ok guys here's an update......

I hard wired the fuel pump and ran it for a split second up to three times to verify that it is not the fuel pump. So fuel pump works and this is not the issue.

I have checked ALL fuses and relays and there is no bad fuse or relay anywhere on these. This includes the cigarette lighter fuse, which is ok and I am still unable to get my OBD II reader to connect.

I have traced back all the wiring from the fuel pump itself up to the engine block and all wiring and wiring harness' are ok. No cuts, tears, melted wires or loose connections.

I checked connections over the passenger wheel well towards the PCM and everything is nice and tidy, no loose connections, cuts, tears or anything.

I checked the ground connection behind the driver's side head and it is snug and tight, not loose.

I am still not getting the fuel pump to power on/turn on. >=(

Anybody have any ideas where else to check? I am convinced it is a ground somewhere, but have no clue as to where else to look? I have checked all grounds in the engine bay that are easy to check and inspect and they are fine. Have not looked at grounds that are located underneath the car, if any.

Somebody please help, if any available.

I do not have the funds to take this car in to a shop and get charged a ridiculous amount per hour for labor.

Is there a fusible link for any of the computer or fuel pump power? also make sure your battery connections are tight.

did you check for power at the relay harness?remove relay ,turn key on ,use test light and check all sockets of the relay harness.is the battery cables tight?

when you said that you hard wire the pump, did actually run it with some wiring straight to it or did you pulled the relay out and put a small piece of wire to overide the relay? You need to start checking for power at the relay socket 1st to make sure it's getting power. If the pump works with the small jumper at the relay socket then the realy is bad or the wire that sends the power signal to it is open somewhere.

I have a feeling the no communication with the PCM with your scan tool and the non running fuel pump are related since the PCM controls the fuel pump relay. It seems like the PCM isn't getting either power or ground to wake up.
The Service Vehicle light also supports this because one the things that triggers that is loss of communication between the IPC and another module (ie PCM).
Refer to the schematic I posted earlier and check for power at those fuses. I know you said the fuse themselves are ok, but I wanna know if there is voltage at those fuses.

Post the results and we'll go from there.

Ok guys I'll go ahead and check these things while I wait for my friend to get here with hos HP Tuners to data log and I'll be able to determine where there is communication and where there isn't.

JayTA98, I hard-wired it directly to the pump, so ill try jumping it with a wire at the relat switch also before my friend gets here.

ok bud. Good luck. Keep us posted.

Ok guys here's the update.

Just spent the last 3 hours with my friends trying to figure out wtf is going on. We've come up empty and Cutlass, you're the only one who has come closest to helping us out. So hopefully, you can continue that streak.

So friend plugged HP Tuners in and had the same problem. We're getting power to the connection there, but it is unable to connect, just like my OBD II.

We are getting power through the fuses in both fuse boxes but apparently somewhere between the fuses and the PCM, power is being lost since we cannot communicate with the PCM with anything.

We think that there has to be a short somewhere between the fuse and the PCM, since apparently the PCM won't wake up, like Cutlass said. So tomorrow we're going to try and trace the wiring and see if we find anything.

Let me know if you have any other advice or where to go from here.

have you pulled the connectors off the pcm and checked the pins for corrosion?

yes....we pulled the pcm and pins were corrosion free and looked fine.

we plugged in another pcm that my friend had from another ls1 to see if that would read in case it was my pcm that had gone out but we had the same problem.

so the problem lies somewhere in between the pcm and the fuse boxes in the engine bay

From the schematic I posted earlier, both the battery positive wires go through connector C101. That connector is a 10 terminal connector that runs over the passenger side wheel well. The fuel pump relay control also runs through that connector FWIW.

If you end up finding that the PCM does have power and ground but just isn't communicating with anything else, there is a connector to check for that. Its connector C230. Its a 10 terminal connector inside the car located under the passenger side of the IP, behind the knee bolster.