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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Here's what I got going on in my car right now. 85 z28 started out at 305 TPI switched to carbed 305 bored out with cams, headers. But this fuel pump crap looks like it was an easy fix but it slowly leaks fuel out of this micro electric oump. All I want to do is get this back to stock and put a cover over it because I don't want fuel inside my car. I could use any and all help. I'm not sure how to rewire everything and what to do about buying a new fuel pump as I know some brands are bad quality. Any suggestions would be great
Man that's a horrible hack job.. If you go back stock you will have a high pressure pump feeding the carburetor which won't work without a return style regulator to get the pressure down.
You could change the in tank pump to a lower pressure TBI unit, you would still need a regulator but it would not bypass as much fuel back to the tank..
Man that's a horrible hack job.. If you go back stock you will have a high pressure pump feeding the carburetor which won't work without a return style regulator to get the pressure down.
You could change the in tank pump to a lower pressure TBI unit, you would still need a regulator but it would not bypass as much fuel back to the tank..
as stock I meant just back to not having a fuel pump in my car hahah. So I'm up for aftermarket is what I'm trying to say that's my mistake
You should've seen the crimped fuel lines and wiring mess he left behind for me. Oh and how the PO attempted to put the ebrake on but fed the wrong end in. And how I had neutral switches shorting out my whole system. Theres more! What a nightmare
battman has the right idea. Replace the in-tank pump with a lower pressure TBI pump and use the stock fuel lines (feed and return) as intended. You will need to plumb in a fuel pressure regulator that is suitable for a carb but that is fairly simple. Don't know if your engine has a mechanical fuel pump provision or even if the cam has a fuel pump lobe so some type of electric pump is the easiest way to go. Stock is usually the most cost effective and easiest system to duplicate so following that design is probably the best route. GL!
I run a 255lph wahlboro in-tank electronic pump in my factory carbed 84 T/A. I run a Mallory 4307 return regulator to bring the pressure down to 6.5psi. Zero issues in 8 years and I"ve put about 20K miles on it.
I run a 255lph wahlboro in-tank electronic pump in my factory carbed 84 T/A. I run a Mallory 4307 return regulator to bring the pressure down to 6.5psi. Zero issues in 8 years and I"ve put about 20K miles on it.
would this cause issues as my engine started out as TPI? I'm really clueless at all this stuff
battman has the right idea. Replace the in-tank pump with a lower pressure TBI pump and use the stock fuel lines (feed and return) as intended. You will need to plumb in a fuel pressure regulator that is suitable for a carb but that is fairly simple. Don't know if your engine has a mechanical fuel pump provision or even if the cam has a fuel pump lobe so some type of electric pump is the easiest way to go. Stock is usually the most cost effective and easiest system to duplicate so following that design is probably the best route. GL!
What do I do about all the wires that are hacked up?
I run a 255lph wahlboro in-tank electronic pump in my factory carbed 84 T/A. I run a Mallory 4307 return regulator to bring the pressure down to 6.5psi. Zero issues in 8 years and I"ve put about 20K miles on it.
I forgot to add it has an edelbrock 650 thunder series 4 bbl carb
What do I do about all the wires that are hacked up?
If you're handy with a soldering iron you can join them together and use heat-shrink tubing. Otherwise you would have to replace the entire line(s) from the tank to the connector towards the front. I would at the least solder them to ensure a permanent intermittent free operation.
If it were me, Id be checking to make sure the cam has a fuel pump lobe, and there is a good hole in the block for the fuel pump pushrod where you can slap a mechanical pump on there. Solder up the wires, Use shrink wrap, Then wrap them up in loom and then tape up the loom nice and tight. Take out the electric intank pump, Bypass it with hose, Double clamp each end, and verify the system works before you weld and seam seal up that hole. Might have to pour some gas in the carb to get it going. No regulators to fail and spray fuel everywhere, No dropping the tank again, And no figuring out where to mount that cheapo Mr Gasket electric pump thats in there at the moment thats probably gonna leave you stranded somewhere
If you're handy with a soldering iron you can join them together and use heat-shrink tubing. Otherwise you would have to replace the entire line(s) from the tank to the connector towards the front. I would at the least solder them to ensure a permanent intermittent free operation.
thanks so much is, is there a wiring diagram I can refer to online since one wire (orange with white strip is coming from the connector at the fuel pump but goes nowhere and is taped off
If you're handy with a soldering iron you can join them together and use heat-shrink tubing. Otherwise you would have to replace the entire line(s) from the tank to the connector towards the front. I would at the least solder them to ensure a permanent intermittent free operation.
awesome I'm gonna do some more research and look at what I got in the engine to work with.
Originally Posted by 86CamaroDan
If it were me, Id be checking to make sure the cam has a fuel pump lobe, and there is a good hole in the block for the fuel pump pushrod where you can slap a mechanical pump on there. Solder up the wires, Use shrink wrap, Then wrap them up in loom and then tape up the loom nice and tight. Take out the electric intank pump, Bypass it with hose, Double clamp each end, and verify the system works before you weld and seam seal up that hole. Might have to pour some gas in the carb to get it going. No regulators to fail and spray fuel everywhere, No dropping the tank again, And no figuring out where to mount that cheapo Mr Gasket electric pump thats in there at the moment thats probably gonna leave you stranded somewhere
If you're handy with a soldering iron you can join them together and use heat-shrink tubing. Otherwise you would have to replace the entire line(s) from the tank to the connector towards the front. I would at the least solder them to ensure a permanent intermittent free operation.
so I only need to rewire those wires, hook up the hose, and run a mechanicall pump and I should be good. No regulator needed?
Originally Posted by 86CamaroDan
If it were me, Id be checking to make sure the cam has a fuel pump lobe, and there is a good hole in the block for the fuel pump pushrod where you can slap a mechanical pump on there. Solder up the wires, Use shrink wrap, Then wrap them up in loom and then tape up the loom nice and tight. Take out the electric intank pump, Bypass it with hose, Double clamp each end, and verify the system works before you weld and seam seal up that hole. Might have to pour some gas in the carb to get it going. No regulators to fail and spray fuel everywhere, No dropping the tank again, And no figuring out where to mount that cheapo Mr Gasket electric pump thats in there at the moment thats probably gonna leave you stranded somewhere
Correct, no regulator needed. I would verify you can run the mechanical before you buy anything. Some engines the block was never machined for the pushrod. I might have a fairly new mechanical pump and pushrod kicking around too if you need it. I went efi/electric pump last year.
thanks so much is, is there a wiring diagram I can refer to online since one wire (orange with white strip is coming from the connector at the fuel pump but goes nowhere and is taped off
According to what info I have - it's very simple - blk wire is ground - org/wh
is going to the fuel pump relay ( or was) at one point.
If the car originally had an intank pump then the wires should be purple for the sender, black for common ground and Grey for the Fuel Pump. The interior cabin side female three prong connector looks like it was cut off or removed? You can buy a new sending unit which consists of the entire intank unit minus the fuel pump, the hard lines that connect to the soft lines inboard of the driver's rear wheel and the three pronged connector.
If the car originally had an intank pump then the wires should be purple for the sender, black for common ground and Grey for the Fuel Pump. The interior cabin side female three prong connector looks like it was cut off or removed? You can buy a new sending unit which consists of the entire intank unit minus the fuel pump, the hard lines that connect to the soft lines inboard of the driver's rear wheel and the three pronged connector.
Hard to make out the colors but there are 3 wires coming from the fuel assmbly - blk(gnd),
tan(?) 12v operation - that leaves the orange(?) which is connected and is used for the fuel gauge on the dash. That is all!
Hard to make out the colors but there are 3 wires coming from the fuel assmbly - blk(gnd),
tan(?) 12v operation - that leaves the orange(?) which is connected and is used for the fuel gauge on the dash. That is all!
I was mistaken, GM switched to purple, grey and tan later. The OP's year used the black as the common ground, Tan for the fuel pump and Pink for the fuel sender.
Source: http://austinthirdgen.org/mkportal/m...ine_wiring.gif
Nothing should need rewired, just reconnect the body wiring to the sending unit wiring. Then just reconnect the hoses/lines. You should probably go ahead and replace the fuel pump while it is easy to do with your trap door open. For a fuel pump go with the AC Delco fuel pump EP381 it was used in the Typoons and Grand Nationals. The Holley Fuel pump didn't last very long in my car and was noisey, the EP381 is a little quieter and so far so good on the life span.
That Austin site has some great docs/diagrams. The one GM factory Service Manual for the 3rd gen that I have refers to another manual for electrical connection, which I don't have. Great source.
Nothing should need rewired, just reconnect the body wiring to the sending unit wiring. Then just reconnect the hoses/lines. You should probably go ahead and replace the fuel pump while it is easy to do with your trap door open. For a fuel pump go with the AC Delco fuel pump EP381 it was used in the Typoons and Grand Nationals. The Holley Fuel pump didn't last very long in my car and was noisey, the EP381 is a little quieter and so far so good on the life span.
After I connect the wires and put EP38Q in I'm still not done though right I need the regulator and install a manual fuel pump
After I connect the wires and put EP38Q in I'm still not done though right I need the regulator and install a manual fuel pump
I misread your initial post, I thought you were going back to EFI. If you are staying carb you have 2 options:
1. Use a TBI stock fuel pump in the tank and good name brand fuel regulator. If you are using a TBI pump you will need to use fuel hose that is rated for the higher pressures of Fuel injection.
2. The fuel pump is actually connected to the sending unit with a short length of tube. I would just remove the pump and use a short length of hard line in place of the intank pump. Then install your pre-existing little electric fuel pump under the hood with a regulator. You won't have to use EFI hose for this.
I misread your initial post, I thought you were going back to EFI. If you are staying carb you have 2 options:
1. Use a TBI stock fuel pump in the tank and good name brand fuel regulator. If you are using a TBI pump you will need to use fuel hose that is rated for the higher pressures of Fuel injection.
2. The fuel pump is actually connected to the sending unit with a short length of tube. I would just remove the pump and use a short length of hard line in place of the intank pump. Then install your pre-existing little electric fuel pump under the hood with a regulator. You won't have to use EFI hose for this.
Okay I'll weigh my options and see what's best for me
09-08-2016, 10:58 AM
