do I need a v8 fuel pump? help 1995 firebird V6 to V8 swap
04-21-2007, 05:38 PM
#1
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do I need a v8 fuel pump? help 1995 firebird V6 to V8 swap Allright, I am getting sick of doing my wiring but this is all that is left for my car to run, I have a 1995 firebird 3.4l V6, well now it has the Ls1. I got the engine to crank over but it wont give out spark unless the computer runs the fuel pump. There is a difference between the pumps, like 2 or 3 wires more on the V8 than the V6, I think if I get a V8 fuel pump and then just wire it up with new wiring through the body to the computer, umm I dont know guys give me some Ideas..
04-22-2007, 05:37 PM
#3
I noticed the PCM wouldnt fire spark too unless the PCM saw the fuel pump relay on a 5.3L swap I did recently. I had wired the fuel pump relay backwards by mistake. There is a fuel pump relay diagnostics that can be disabled in the PCM. Also, make sure you're relay is wired correctly.
remember the PCM controls POWER going to the relay. Other leg of the relay coil should be grounded. This is backwards to how the PCM controls fan relays, which is by controlling the GROUND.
good luck.
remember the PCM controls POWER going to the relay. Other leg of the relay coil should be grounded. This is backwards to how the PCM controls fan relays, which is by controlling the GROUND.
good luck.
04-22-2007, 05:40 PM
#4
Originally Posted by greenfbodyracer
... it wont give out spark unless the computer runs the fuel pump. ..
So is it running okay when you let the PCM control fuel pump? You could have a VATS issue on top of that too. The fuel enable signal from the BCM was likely a fuel enable wire on you're V6 car, on the LS1 fuel enable is likely supposed to be via Serial Data.
04-22-2007, 10:11 PM
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I probally have something wired wrong, I will take another look at it on monday, but I have the gas pressure wire not connected to anything because there is nothing to connect it to, should I just ground it or give it 5 volts?? But I do want the computer to run the fuel.. But that serial data- is for the OBDII connecter not the fuel.. because I got my OBD scanner to read the PCM..
Thanks guys,,
Thanks guys,,
04-22-2007, 11:01 PM
#6
What gas pressure sensor wire? Where does it go to on the PCM? I think you are referring to the Fuel tank pressure sensor which is not needed to make the car run, it is for emissions. I attached the fuel tank wiring diagrams for an 99-02 LS1 f-body.
04-23-2007, 02:05 PM
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Allright then I was referring to the fuel tank pressure wire.. Thanks for the diagrams, G-body, hopefully I will see something happen tonight, Hopefully,
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04-23-2007, 08:05 PM
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Thanks guys for all the help, I got the fuel pump to run now but I cant seem to get spark,,, but Now I am looking at all my connections,, and which wires I have hooked up, If you have any input on some help for me,, please do
04-23-2007, 09:49 PM
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I had the same issue. I used a push button start after 3 ignition switches didn't help. My problem was simular, I was only getting spark as the key turned back towards the on position from the start position. So instead of losing my mind with the wiring I hooked up a push button start. The key must still be in the ignition in the on position. Then the push button "bypasses" the ignition switch. That is what I did, i know it's not the "correct" fix, but it did work, and still does and cost me $8.
As for the fuel pump, glad you got it working, but what pressure does it make at the fuel rails? I had to ditch my V6 pump, and went with a Walbro 255. To advoid the wiring issue you were referring to from the tank, i kept the V6 fuel pump assembly, and removed only the V6 pump itself. In it's place went the Walbro using the origional wiring, and it plugged up just fine, as there were no modifications made to the plugs. Just added a fuel regulator under the hood, adjusted it to 59psi, and it all works. If i can help just send me a PM.
As for the fuel pump, glad you got it working, but what pressure does it make at the fuel rails? I had to ditch my V6 pump, and went with a Walbro 255. To advoid the wiring issue you were referring to from the tank, i kept the V6 fuel pump assembly, and removed only the V6 pump itself. In it's place went the Walbro using the origional wiring, and it plugged up just fine, as there were no modifications made to the plugs. Just added a fuel regulator under the hood, adjusted it to 59psi, and it all works. If i can help just send me a PM.
04-24-2007, 01:32 PM
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Well i got the car to run to day!! At 9:07 this moring.. Thanks for all the help
There was a wire on the crankshaft poss. sensor that was damaged.. so that why I wansnt getting any spark..
There was a wire on the crankshaft poss. sensor that was damaged.. so that why I wansnt getting any spark..
