wiring up 255 fuel pump questions

skipztt

boost
im gonna put in a 255 some time this week. i was reading that for some people, it pulls too much power, and they have idleing issues or staling. is there a certain way to wire it without these issues? or should i just hook it up normal and cross my fingers. i dont want to have to drop the tank again if i have issues.

also i can get a granitelli 255 from summitt racing for $90.00. its for a trans am/ camaro/ gm. it should work right? does anyone else have one on theres?
thanks in advance
 

SY2932

Administrator
Re: wiring up 255 fuel pump questions

Never went to a bigger fuse when I did my swap over six years ago and haven't blown it once. I'm convinced "ground maintenance" has a lot to do with this. When I redo the grounds for fuel pumps, and I do redo everyone, the ring terminal gets soldered after it gets crimped on. Then the frame is grinded down to bare metal before it is reattached with lots of grease. Also be sure to "loose" the pulsator when you do the swap:

"Pulsator that is removed during fuel pump swaps, the short length of rubber hose is used to replace it. Hose gets clamped from the output of the pump to the fuel line on the sending unit."
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

Only problem Ive had is that Ive split 3 hoses in a year and a half. I am currently upgrading the whole set up and Ill be using the fuel pump to line hose that comes from Racetronix. It looks like a big flexible straw. I am also going to be doing the wire mod with a relay. Im not sure yet how its set up but I want to sure I dont have to take this tank out again. Im also having 3' long fuel lines made to go between the tank sending unit nad the lines that go forward. This way I can drop the tank alone and get the lines undone with ease.
 

Don W.

Stab it and steer it
Re: wiring up 255 fuel pump questions

The Racetronix harness will take care of all that, just clean the grounds as mentioned. No issues with my install, didn't change the fuse because the harness eliminates that prob.
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

Don W. said:
The Racetronix harness will take care of all that, just clean the grounds as mentioned. No issues with my install, didn't change the fuse because the harness eliminates that prob.

Im just going to make my own. A local S/C Turbo shop has experience with it and they say you can make the kit for $10 so thats my plan. I have a bigger fuse in there now but will be going back down when I get it all done.
 

canadian

sy in progress
Re: wiring up 255 fuel pump questions

There's no way you're getting all of the parts to make a Ractronix setup for $10. Relay, wiring, terminals, split loom. Show us the receipts.
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

I have a realy that I paid $4 for , I have a roll of 10 Gauge wire I bought for $4, Ihave tons of connectors Ive accumulated over the years which usually go for a couple bucks in variety packs. Tell me why it would cost me a whole lot more?
 

Don W.

Stab it and steer it
Re: wiring up 255 fuel pump questions

TYTILIDIE said:
I have a realy that I paid $4 for , I have a roll of 10 Gauge wire I bought for $4, Ihave tons of connectors Ive accumulated over the years which usually go for a couple bucks in variety packs. Tell me why it would cost me a whole lot more?

Hey, go for it. At my age it's usually easier to buy the proven, I know it'll fit, part.;)
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

Truthfully I dont see the big deal, essentialy its a 10 gauge wire with relay. Hard to screw up IMO. Mine will not look anything like the Racetronix as it will be a bit simpler. I dont see why it wouldnt work the way IM going to do it. Hopefully Ill be getting my fuel line and hanger assy back today and I can build it and take pics.
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

So I learned that maybe I shouldve just bought the Racetronix harness. I hooked everything up and I know it s done right but for some reason the relay wont shut the pump off when you turn the key off. Even if I can get it to work right which Im sure I will I spent about $25 on this and for the amount of crap I had to endure I would have to say Ill but hte haRNESS IF THE OPPORTUNITY PRESENTS ITSELF. I guess $70 isnt too bad.
 

Don W.

Stab it and steer it
Re: wiring up 255 fuel pump questions

My first thought is, depending on the style of relay and how it's wired, my bet (not having seen the thing), is that the relay is remaining energized by the hot wire coming from the alt.
 

MRKING

New Parts for Old Trucks
Re: wiring up 255 fuel pump questions

Some relays have to be diode isolated in certain situations . Your relay have 4 or 5 terminals on it ?
 

MRKING

New Parts for Old Trucks
Re: wiring up 255 fuel pump questions

Do you have it wired up like this or no ?
30- to fuel pump
85- old + to fuel pump
86- ground
87- + from alt
 

TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

The relay is hooked up exactly like that. It has 4 terminals and is a 40 AMP. This is really pissing me off because I drove around with it hooked up for a while and had awsome FP which I havent had for a while. I ran 19psi no sweat. I cant wait to get this thing figured out. The relay I got was from Pep Boys and was a R3024 I believe.
 

myclone

Donating Member
Re: wiring up 255 fuel pump questions

MRKING said:
Do you have it wired up like this or no ?
30- to fuel pump
85- old + to fuel pump
86- ground
87- + from alt
TYTILIDIE said:
The relay is hooked up exactly like that.

You sure? IIRC off the top of my head concerning the relay you have if 85 and 87 are connected opposite what is listed above your fuel pump wont shut off.

Reason being is the 87 term goes to the alt which goes to the battery. If 87 is actually hooked to 85 which is the switched + leg for the fuel pump then it will run all the time since its essentially hooked directly to the battery via the connection at the alt.

Id double check just to be sure :2cents:
 

MRKING

New Parts for Old Trucks
Re: wiring up 255 fuel pump questions

The info I posted was for the 5 pin spdt relay . 4 pin I cant think of off hand and would have to check my mecp book .
 

Quickstop [UK]

Combating adversyty.
Re: wiring up 255 fuel pump questions

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TYTILIDIE

METH HEAD
Re: wiring up 255 fuel pump questions

I triple checked and its set up up exactly like this. I have no idea what the hell is wrong here. My brother was an electrician for the NAVY and came over and checked it out and said it was hooked up right. Maybe I got the wrong relay?
 
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