Finished NBS V8 conversion (only one problem)

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03-31-2006, 10:53 AM
jjohnson

I just finished switching my 2004 4.3 v6 with a 2003 4.8 v8. The physical conversion was flawless. Motor mounts were the same and driveshaft was the same length also. Along with the v8 motor, I used it's transmission, transfer case, brain, motor harness, fuse box, fuel lines, air box, radiator, fuel pump along with the electronic throttle setup that replaced the existing throttle cable setup; which simply included the pedal, 1 pigtail harness to the throttle control module, which the motor harness plugged into the other end. Every wire connection went together no problem. Note: I did not change the in dash harness. Every conceivable option that I had in the truck seems to be working properly, including the turn signals, all lights, dash cluster lights, radio etc... The only problem I am having is that the vehicle won't turn over or fire up. The fuel pump won't even engage. I'm pretty sure that all my connections are plugged in. Note: all components worked before conversion took place. At first I thought It might be in theftlock mode, so I attempted to do a relearn procedure to fix the situation but the theft light disapears with the rest of the cluster lights after attempting to start vehicle exept the check engine light. The check engine light stays on. Also the dash digitally says: Service brake booster. And there you have it. I was really hoping that someone might be able to critique what I have done, and possibly point out something that I might have missed or overlooked. Any suggestions or thoughts will be much appreciated.
03-31-2006, 11:42 AM
1BADC10

I'm sure there's some code stored. Know anyone with a scan tool close by?
03-31-2006, 03:28 PM
jjohnson

<div class='quotetop'>QUOTE(1BADC10 @ Mar 31 2006, 11:42 AM) [snapback]48876[/snapback]</div>

Quote:

I'm sure there's some code stored. Know anyone with a scan tool close by?
[/b]

Yeah I know someone with a scan tool. I'm not sure, but I'm probably going to have to reprogram the pcm. I don't think you can do that with a simple scan tool can you?
03-31-2006, 03:35 PM
motoxlifer

Sounds like something with the ignition switch is wrong. Don't ask me what, but when you turn the key forward it should prime the fuel pump & engage the starter.
03-31-2006, 04:52 PM
motoxlifer

I was reading some of Reds comments in your other post. Did you check into the neutral saftey switch like he said? I don't think that would keep your fuel pump from working but you may have more than one problem. I would check the nss and make sure your fuel pump & relay are both hooked up properly.
03-31-2006, 09:05 PM
jjohnson

<div class='quotetop'>QUOTE(motoxlifer @ Mar 31 2006, 04:52 PM) [snapback]48908[/snapback]</div>

Quote:

I was reading some of Reds comments in your other post. Did you check into the neutral saftey switch like he said? I don't think that would keep your fuel pump from working but you may have more than one problem. I would check the nss and make sure your fuel pump & relay are both hooked up properly.
[/b]

No I haven't done that yet.
04-02-2006, 10:25 AM
Time2Kill

The PCM will not keep the truck from cranking or the fuel pump from priming. You have other issues than the PCM at the moment. Check ignition wires along with the relays.
04-07-2006, 01:43 AM
jjohnson

:thumb: Just wanted to give you guys an update on the swap. It turns out my problem or problems I should say was the fact that I had absolutely zero relays in the fuse block under the hood and I had to change the wiring behind the dash (which I might add was probably the hardest, most difficult thing i've done since Marine boot camp). Anyhow, the truck runs beautifully and I am extremely impressed with the difference performance wise. Now the next thing to do is get a custom tune and a performance exhaust. Again, thanks for all your help.

:burnout: :burnout:
04-07-2006, 08:00 PM
Time2Kill

<div class='quotetop'>QUOTE(jjohnson @ Apr 7 2006, 12:43 AM) [snapback]49539[/snapback]</div>

Quote:

:thumb: Just wanted to give you guys an update on the swap. It turns out my problem or problems I should say was the fact that I had absolutely zero relays in the fuse block under the hood and I had to change the wiring behind the dash (which I might add was probably the hardest, most difficult thing i've done since Marine boot camp). Anyhow, the truck runs beautifully and I am extremely impressed with the difference performance wise. Now the next thing to do is get a custom tune and a performance exhaust. Again, thanks for all your help.

:burnout: :burnout:
[/b]

Why was it necessary to change out the wiring behind the dash?
04-08-2006, 09:22 PM
jjohnson

<div class='quotetop'>QUOTE(Time2Kill @ Apr 7 2006, 07:00 PM) [snapback]49588[/snapback]</div>

Quote:

Why was it necessary to change out the wiring behind the dash?
[/b]

It was necessary to change the wiring behind the dash because, although every connector was the same and went together properly, the pins within the connections were different. For example there were different color wires in some spots, and in others there were none at all. These differences were mainly in the wires that went to the fuel injection and PCM unit. Just for clarification, those group of wires that went to the fuel injection and PCM unit came tied in with the in-dash wiring harness coming through the firewall. Both groups of wires bypass the engine fuse block and go straight to the fuel injection and PCM.
04-09-2006, 05:44 AM
NITROUS

Awsome man! I know you're happy with that setup. :thumb: