Well I'm moving to the pontiac side! I found an 87 T/A that is going to be the recipant of my 84 Z's carb'd 350 which is non computer controlled. The problem is that the 87 was TPI and has the stock in tank fuel pump. Is there even a problem there? Does the stock pump need power?

Is there anything else that runs through the computer I'm eliminating that I'm still going to need when I have the new engine in there? Does the speedo run through there? Anything else? I want to get the swap done in one weekend and don't want to have to run and get parts while I'm neck deep in grease.

Thanks for your time,
Matt

 

don't think you'll have any problems elimanating the ecm. you can rewire the fuel pump, the harness is under the back seat, 3 wires or go with a mechanical, it'll work with the factory pump still in place.

 

Do you mean that it'll work with the electric not running? I've been wondering this myself.

Didn't GM use both on the later CC carb setups before they went to TBI?

AJ

 

The mechanical pump will not pull thru the in-tank one. As much of a pain as these tanks are to drop you need to get rid of it.

 

mine wouldnt siphon through either...i rewired my intank pump as Ede said and have a Malory 3 port afpr..no problems to date.

Its a strange thing...some will some won't..

 

yep they did..trying to stop vaporlock...Some 87's I think

 

here AJ check this out.......https://www.thirdgen.org/techbb2/sho...hreadid=111680

 

I dont think that sometimes it works and sometimes it doesent is an acceptable answer, there has to be a reason it does or does not work. I don't know how to bypass the factory pump and I'd much rather just use the in block pump pump and have it pull through the factory.

What is the answer:
1. Block pump will pull through in-tank pump without power.
2. Ditto - except with power
3. In-tank pump will need to be bypassed.

Thanks,
Matt

 

sorry Matt, I dont know why....it just seems to be so...some will some wont..all I can say is try it...and move this TTT for more input.

 

The reason it won't pull through is there is too much restriction for the mech. pump to pull through. The only way around it is to drop the tank, remove the pump altogether and extend the pick-up tube to the level of the sock. And no; putting full shop air thru the lines won't blow out the electric pump internals.

 

Well I could reuse the factory in-tank pump. I was thinking of buying the Painless fuel pump wiring kit and then buying a pressure regulator similar to the one Elebrock makes that sits in front of the carb. I know nothing about fuel line running, but am expirianced with car electronics. How would I go about plumbing the system if I went this route?

BTW, thanks a lot for all of the help!

-Matt

 

I bought the Malory 3 port AFPR from summit. cost about $80 and is real easy to plumb in. your car has 3 lines coming from the tank. One is the feed. one is the return, the other is the vent and goes to the charcoal cannister. the feed line connects to one port on the side of the regulator...the carb to another side port...the return out the bottom of the regulator... Simple...you will also need a fuel pressure gauge I used an inline that cost about 6 bucks.

 

sorry about the LARGE pic ...eeeks

 

Cool, that helps a lot. I'm thinking about going that route now. Just a few more questions...how did you wire up your stock pump and how do I know which lines are which?

Thanks again,
Matt

 

If I am not mistaken there are two different diameter lines. The larger one being the feed line. I would trace the fuel flow from the filter in the back of the car to be sure.

 

I think the larger is the return....just pull them off put them in a can and turn on the key...you will know for sure, ya have to take them off anyway.
For wiring I went between the back seats there is arelay there with 3 wires...cant remember what color without looking, you must ground the pump(1 wire) Run a hot to a switched sorce in your fusebox. You should wire in a oilpressure switch for safety. Otherwise the pump could keep running after a wreck and fuel a fire. I didnt...yet. The pump runs all the time...the fuel circulating(sp) continuously helps to keep the fuel cool. I havent had any problems with mine. Do a search on fuel pump and you will find a couple of different ways to do it...as well as the wire colors.

 

BTW, Dont use the teflon tape like I did..Ive since removed it.

 

Hey rileys... what exactly are you saying here about rewiring the fuel pump?? I am going to try to the route of using the stock v6 fuel pump with my 406... i bought the mallory fuel pressure regulator like you have my only concerns are is my return line going to be big enough to lower the pressure enough...?

 

My pressure is set at 6lbs ....no problems and my fuel pump puts out around 40psi.... just make sure your vent line is clear, I dont think you need to worry.
As for rewiring the pump....once you go with a carbed setup, HEI ignition, the computer will no longer tell the pump to run..it will prime....then stop running and you will run out of fuel. You will have to bypass the ecm and wire the pump direct. This is done by bypassing the relay between the back seats. ( there are other methods also). Its real easy to do, dont get discouraged. there are 3 wires coming from the pump to the relay..ground...hot..and I believe the third goes to the ecm...I can look tomorrow and tell you the colors if you need. You need to wire the hot wire to a keyed source in the fuse panel so the pump will run all the time. Ground the ground......If you look , you will see what I,m talking about....I have a camera and can take pics if you have problems as you go. Just e-mail me and I will be happy to help. Lets save the bandwith for others.

 

where exactly is the relay located? right in the middle of the back hatch area... or actually down behind the seats? If you had some pics it would be helpful but if not dont worry about it. Thanks

 

The relay is between the back seats...just below the hatch area ,you will need to pull up the carpet in order to see it...if you get under the car you can see where the wires come in from the fueltank. Id rather not pull mine apart for pics...but if you look again and cant see what I m talking about..i'll take some . Pull the carpet up from behind the seats,,,,you will see it

 

If I am not mistaken all of the relays are mounted on the firewall near the brake booster. One for priming, one for running. I do not know the function of the third. I have been in the back seat and did not see one there. Is relay setup different on the Camaro?

 

Does anyone have any idea how i would go about hooking the stock pump up to a toggle switch inside of the car?

 

do a search on wiring fuelpump....lots of info.....

try this...https://www.thirdgen.org/techbb2/sho...ring+fuel+pump

 

A long time ago I sent someone detail of the fuel pump relay wires. Do a search of the archived. What I would do is tap in to the wire that the ECM sends voltage to to activate the relay. You can use a switched block on the fuse box and you should be good to go. This should still allow the oil pressure cut-off to function. Sorry it's been a while sice I dealt with the fuel injection relays.