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pump rewire.. pain in my but, need answers plz

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Old 01-03-04 | 12:02 PM
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pump rewire.. pain in my but, need answers plz

i rewired my fuel pump with the schematic from nzconvertible i think.. the one he made.. and its been running funny.. i didnt check the voltage on the fuel pump when i did it cause it ran.. well i guess 12V was running to it the whole time.. wich made my idle crap.. i checked it today and it was 12v. so i checked my wiring.. i know i tightened and crimped everything down good. well come to find out the schematic i had from nzconvertible.. the relay is different in it than the one i got from radioshack.. but its the part # from the writeup on 1300CC. so i moved it around to what i thought would work according to the drawn out schematic on 1300CC, now it has 9v at idle.. but it idles like CRAP, itll idle and then when i rev it, and then let off the gas.. when the rpms drop back down, they just drop till it dies.. if i rev it to like 1k rpms itll drop and almost die and then come back up and then down and then idle. WTF IS HAPPENING
Old 01-03-04 | 01:17 PM
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at what point does the resistor kick off.. and make 12v instead of 9? and can you make this happen while in neutral?
Old 01-03-04 | 03:45 PM
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ON a normaly wired turboii, it's pin 3D on the ECU that determines whether you get 9 or 12volts. It puts a ground on a relay inside the fuelpump resistor relay. But when the ECU sees a LOAD put on the engine, it removes that ground and the relay relaxes and bypasses the resistor and now gives you 12volts.

You can unpin the pin 3D in the small plug on the ECU and walla, you now have 12v all the time.

In other words the determining factor as to getting 9 or 12v is ........load, determined by the pressure/boost sensor.

At idle this morning, I pulled/reinserted pin 3D numerous times and noted no change in the idle of the engine. Although I'll begrudingly admit the afr did get richer by .1afr when the pin was disconnected.

You do know that on a series four you have a solenoid resistor??? And at idle it will make the mixture richer/leaner???? Have you tried that?
Old 01-03-04 | 04:05 PM
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Tripping the relay while in neutral seemed pretty hard when I tested it. There are a set of conditions that will trip the relay, In my experience when I tested it any one or one or more of these conditions will trip it.

3800 rpms
moderate boost
WOT

Your pump should see 9V at idle or while cruising. Not sure about cruising above 3800 rpms.. I don't remember.

Err..I know everybody hates to hear this but err.. recheck all connections. If you can find that box/instructions that came with your relay and check that schematic to make sure.

I do recall you adjusting your rich/lean idle mixture screw
on a different thread, maybe you should readjust that.
Old 01-03-04 | 04:19 PM
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#1 i think i have a vacuum leak.. #2 i have already re-adjusted the idle mixture resistor many times.. #4 i moved everything back to normal and am going to hookup this "rewire" a different way, hailers.. id like to talk to you about it actually, can you PM me? i saw a post of yours on teamfc3s that was a much better way of doing things. actually i was learning how this fuel pump resistor/relay worked and thought that its stupid to run 3 big wires all the way to the back of the car when you can do it all in the front, or at most run 1 wire.. grrrr. my overall sense of this project = very bad. wish i woulda thought about it all before i did the cutting
Old 01-03-04 | 07:40 PM
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There really isn't a better way of doing the rewire, because this is the only way that leaves everything working exactly as the factory intended.

You're not running three big wires either, it's one big wire and a skinny speaker cable.

If it's done correctly, there should be no side effects. The first thing you should do is make sure you fix that vac leak. You can't blame the rewire for a poor idle until you know that's fixed.
Old 01-03-04 | 10:22 PM
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I just did 'that' rewire today ... It worked just fine for me. Double check everything ... you got something wrong.

here is a pic;
Old 01-03-04 | 10:34 PM
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Originally posted by Slacker7
Tripping the relay while in neutral seemed pretty hard when I tested it. There are a set of conditions that will trip the relay, In my experience when I tested it any one or one or more of these conditions will trip it.

3800 rpms
moderate boost
WOT

Your pump should see 9V at idle or while cruising.
I am very glad to see this post.
My pressure sensor was erratic when I got the car, and it died last month, so I was worried about low pump voltage.
The WOT & 3800rpm triggers are doing the trick.
Old 01-03-04 | 11:06 PM
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no it def. was the rewire.. only it was my fault that i didnt look at the back of my package i just used the number off of your schematic. i know this is not your fault nz, as your relay probably had different numbers for each function of the relay. radioshack probably changed them.. but yes there is a better way (imo). depending on what your opinion on WHY youre not getting 12v to your pump is.. heres a few other solutions.

if you think its because you are not getting 12v to the fuel pump resistor/relay.. then do this..

-image i made today.

if you think its because of the WIRE itself is bad.. then just splice the blue wire and run a new one to the back and splice the blue wire at the pump and tie in.

if you think its both, do both and you only have 1 wire to run.

if you find a flaw in this.. i would like to hear. thanks.

thats my opinion.
Old 01-03-04 | 11:12 PM
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I am putting a TII motor in my NA vert and want to know if this is something I will need to do and if so why? What does this change?
Old 01-03-04 | 11:13 PM
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it changes the running of the speaker wire, and the running of the power wire to the back if you thinks its because of the voltage before the fuel pump resistor/relay, plus the pain of remounting it.
Old 01-03-04 | 11:30 PM
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EDIT <HIJACK>Radio shack changing bosh relay numbers? Thats unlikely. Not even sure if they can, UL, IEEE, SAE or somebody would get on their *** for it... and if they didn't I sure as hell would. Not to mention Bosch would probably laugh their *** off (for that matter anyone else who makes relays according to bosch standards [which i would assume are based on SAE standards</HIJACK>\

EDIT: Oh... nm then

Last edited by Kenteth; 01-03-04 at 11:34 PM.
Old 01-03-04 | 11:32 PM
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then they didnt.. it was just off the top of my head? yah
Old 01-03-04 | 11:49 PM
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Originally posted by imloggedin
then they didnt.. it was just off the top of my head? yah
although there are different types of relays that have duplicate switched power supplies, so as to turn on a pair of headlights at the same time.

Edit: I couldn't find the original, so I just hosted it:
http://24.220.177.179/boschtyperelays.pdf

Last edited by Kenteth; 01-03-04 at 11:54 PM.
Old 01-03-04 | 11:53 PM
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man, i dont care about types of relays.. im just posting helpful information and you pick out the tiniest thing to correct lol
Old 01-03-04 | 11:55 PM
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Originally posted by imloggedin
man, i dont care about types of relays.. im just posting helpful information and you pick out the tiniest thing to correct lol
just gotta nitpick what I know
Old 01-04-04 | 01:18 AM
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Originally posted by imloggedin
no it def. was the rewire.. only it was my fault that i didnt look at the back of my package i just used the number off of your schematic. i know this is not your fault nz, as your relay probably had different numbers for each function of the relay. radioshack probably changed them.
My schematic uses the internationally accepted method of numbering the pins of a standard 12V SPST relay. I've never seen a relay that didn't follow these numbers. Pins 30 and 87 are the switch and pins 85 and 86 are the coil. Did the relay you used have the numbers 30, 85, 86 and 87 on it? If it did, there's no way they would mean something different.
but yes there is a better way (imo). depending on what your opinion on WHY youre not getting 12v to your pump is.. heres a few other solutions.

if you think its because you are not getting 12v to the fuel pump resistor/relay.. then do this..
Doing that is pointless. The whole reason for doing the rewire is to completely bypass the stock fuel pump power wiring (small gauge wires, very long route) and run one heavy gauge wire direct to the pump, to minimise the voltage drop that normally occurs. Your alternative method still uses nearly all of the stock wiring, so there will be no reduction in voltage drop. The pump will work, but there will be zero benefits.

Have you considered returning it all to stock to see if that cures the problem?

Last edited by NZConvertible; 01-04-04 at 01:23 AM.
Old 01-04-04 | 04:01 AM
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Originally posted by NZConvertible
The whole reason for doing the rewire is to completely bypass the stock fuel pump power wiring (small gauge wires, very long route) and run one heavy gauge wire direct to the pump, to minimise the voltage drop that normally occurs.
Woa! woa, hold tight there cowboy . Are you suposed to change the wire that runs from the speaker tower to the pump itself? I put the relay in close to the pump, but I left about 2-3 feet of the stock wires connected to the pump. Thats how the explination came across to me.

Do I need to replace ALL the wire, including the last couple of feet that go to the pump?



-Robert
Old 01-04-04 | 07:56 AM
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The more you replace the better, but it'd be a PITA to replace that last bit, and the difference would be minimal. 2-3 feet seems a bit excessive though. It cut mine just before the fuel pump plug, so it can still be disconnected easily.
Old 01-04-04 | 09:51 AM
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tell me what wires you are replacing that i am not if i run a power wire to the pump like i posted.. wait .. the speaker wires? that just ADDs to the wires already there? if you think its the wireing that is not letting you have 12v, then run one wire from the blue up front to the blue in the back and forget the added relay, yay new wire.. why run speaker cable? thats rediculous.. alls your doing is adding an extension to the green/red, black/white.. your not replacing anything with that, only making it longer. and yes those were the numbers on my relay.. and they were different than yours. i know you didnt make the original pump rewire.. you just made the schematic.. but if you look at it youll see that its useless to move everything to the back.
Old 01-04-04 | 02:03 PM
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Originally posted by NZConvertible
Doing that is pointless. The whole reason for doing the rewire is to completely bypass the stock fuel pump power wiring (small gauge wires, very long route) and run one heavy gauge wire direct to the pump, to minimise the voltage drop that normally occurs. Your alternative method still uses nearly all of the stock wiring, so there will be no reduction in voltage drop. The pump will work, but there will be zero benefits.
my alternative method is doing the same thing youd be doing if you did the "normal" rewire, without the extra relay. if the voltage is dropping because of the WIRING.. then replace the WIRE and why worry about the extra relay, and power from battery?

the speaker cable is useless, its only means is to get signal to the back, to switch the relay on, where it doesnt need to go, and your STILL using the same wire as the stocker, because your just splicing into it and adding. the only cable re-ran in the original rewire, that is worth doing, is the power wire to the back. if you think thats the problem then do both of my alternatives, and there is no difference between that, and the original rewire.. besides not moving crap, mounting crap, running more wire.. etc... thats what i posted.. so your comment was invalid.
Old 01-04-04 | 03:20 PM
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I'm obviously misreading you diagram. Stick some labels on it so I can tell what you think you're doing. Where do those wires go? Which ones are new? Are you moving the resistor?

It doesn't matter anyway, because there's nothing wrong with the orginal method. I've done it and it worked perfectly, same with countless other people. If you're having problems with your car, it's not because of the method. Either you have hosed it up completely, or you did it right and have another problem somewhere.
Old 01-04-04 | 10:28 PM
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im not talking about having problems with my car now.. i already know i hooked the original up wrong.. and then i hooked it up right, and it was working.. tada, i dont care about my car right now. im talking about helping people so they dont have to move it all.

u dont move this one.. you just add a relay to whats there. sorry if you dont understand what it is.. but its obvious what it is.. my addition to stock method is.. cut the blue/red wire, and insert your relay.. thats is. doing the same thing as other way except your keeping it up front.. bing.. not hard to understand. much much simpler than the first rewire. and btw if you dont understand it why are you posting against it??????????? odd.
Old 01-04-04 | 10:30 PM
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How much power is actually lost from the 10' run of stock wire? That does not sound right, voltage drop on wire is so small it cannot be usually measured unless it is a bad wire. If you are redoing a circuit differently that's one thing but changing the wire should'nt make any difference at all.
Old 01-04-04 | 10:38 PM
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thats what i think also.. thats why im not going to change the wire, but convincing other people of that .. heh, thats why in my diagram i didnt change the WIRE.. just where the power is coming from, as the original did, but demands that you rerun abunch of unnecessary things.



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