Fixing a jimmy rigged electrical system

[jfrancom101]

https://www.wiringdepot.com/...................This is the place where I order from, great selection and good prices compared to auto parts stores. They also have heat shrink in several sizes and colors. It was just a coincidence that they happen to be in my town. They don't do retail, so I have to order like everyone else. They should have everything you need in the "Terminals" section to replace the wire ends that are rusted, corroded or lose. Napa has little spools of automotive wire if you need to replace any wires.

While you're shopping at some point (asap) you will want to replace the terminal/fusible link on the firewall with the rusty studs and nuts, most Chevy restoration parts places have them.

Thanks for the link! I'll proably get these ordered today. I found some cheaper everstart connectors that I already have that might be able to do the job for the fusible link, but especially if I got moe wiring I'll be doing, like I said I'd like to do things right.

 

[SirRobyn0]

This is the carb I got. I think just a standard 4 barrel

So that is an Edelbrock Thunder AVS Off-Road, 650 cfm carburetor. Generally they put the off road label on a non-emissions compliant carb. But it would be a carburetor that is more sensotive to fuel pressure.

 

[WP29P4A]

Thanks for the link! I'll proably get these ordered today. I found some cheaper everstart connectors that I already have that might be able to do the job for the fusible link, but especially if I got moe wiring I'll be doing, like I said I'd like to do things right.

I started out using the typical auto parts store stuff, but they really look like crap, especially when you have to use lots of them. By the time were done sorting out your wires it would look like a clown ate a bowl of fruity pebbles and threw up in your engine compartment.

I started cutting off the colored plastic and using heat shrink tubing to protect, seal and make it look better. The plastic makes it not crimp as well when using the tool to attach them. You can get the heat shrink tubing in different colors to color code positive and negative if you like also.

 

[WP29P4A]

So that is an Edelbrock Thunder AVS Off-Road, 650 cfm carburetor. Generally they put the off road label on a non-emissions compliant carb. But it would be a carburetor that is more sensotive to fuel pressure.

What would optimum fuel pressure be? for a typical carb.

 

[jfrancom101]

I started out using the typical auto parts store stuff, but they really look like crap, especially when you have to use lots of them. By the time were done sorting out your wires it would look like a clown ate a bow of fruity pebbles and threw up in your engine compartment.

I started cutting off the colored plastic and using heat shrink tubing to protect, seal and make it look better. The plastic makes it not crimp as well when using the tool to attach them. You can get the heat shrink tubing in different colors to color code positive and negative if you like also.

I got them ordered. Not sure when they'll show up but hopefully the once I got hold me over. I got the fusible link wires taken care of. The link itself had a wire that used to be attached to it but was cut off. I tried to get it in the picture. While getting a wire brush to clean up the connections I think I bumped the link into the snow so I guess I'll have to get that sooner than later

 

[jfrancom101]

That pump will fit but it might not be the right one for what you have going on. We need some more info.

First that mf0004 is a 2 port pump. I believe the one currently on my truck is a delphi but part number mf0002, which is a 3 port pump, one in and two out.

Look at the pump that is on there. is it connected to anything? Look at the frame rail by that pump. Do you see the two hard lines to and from the tank?

Here's my oil stain showing what it should and should not look like .

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#1 In from tank
#2 out to carb
#3 out recirculating back to tank
#4 & 5 these are the same lines as #1 & #3 but they are metal and they are attached to the frame rail.

What do we have to work with? Do you see or have any of these lines?

This is what I have on my mechanical pump. I can't beleive how tight it is, I can see why they switched over to electric but hopefully when I get a new one it can be smaller and have more room. I only saw 2 attachment places. One threaded and one not but I also couldn't see super well. I stuck my phone in all the different places to get a better picutre but it was only ok. Can you tell by the pictures?

 

[gotyourgoat]

This is what I have on my mechanical pump. I can't beleive how tight it is, I can see why they switched over to electric but hopefully when I get a new one it can be smaller and have more room. I only saw 2 attachment places. One threaded and one not but I also couldn't see super well. I stuck my phone in all the different places to get a better picutre but it was only ok. Can you tell by the pictures?

Looks like a one in one out pump, so this engine was from something older than your truck. Did you find the stock fuel lines? This was originally diesel correct? If the original lines aren't there or they are incompatible with the gas system then this page will help at least show you what you should have. https://www.lmctruck.com/1973-87-chevy-gmc/cc-1973-87-pre-bent-fuel-lines-and-vacuum-advance-line

 

[SirRobyn0]

What would optimum fuel pressure be? for a typical carb.

Honestly I have no idea what the published spec is for max pressure on a Q-jet or for that matter if there even is one, but the Q-jet seems to be fine with as high as 8 or even 10psi. Edelbrocks like to leak past the needle and seat if they are much higher than 6psi and the edelbrock fuel pump is factory set to make that amount of pressure. In the old days we never saw pumps that produced to much pressure. Now a lot of the low cost over the counter units seem to be higher, more around the 8 to 10 mark. You gotta keep in mind once the fuel gets into the float bowl there is no pressure, it's draw in by vacuum from there. So you only need enough pressure to get fuel into the bowl. So for that reason getting enough volume of fuel is far more important than pressure. But at least some pressure is required to produce volume obviously. The best setup is the lowest pressure that will produce enough volume to supply fuel to the carb in all conditions. Generally around 4 - 6 psi is safe. I'm running 3 1/2 psi on my regulator and that seems to be enough for my motor.

 

[SirRobyn0]

Looks like a one in one out pump, so this engine was from something older than your truck. Did you find the stock fuel lines? This was originally diesel correct? If the original lines aren't there or they are incompatible with the gas system then this page will help at least show you what you should have. https://www.lmctruck.com/1973-87-chevy-gmc/cc-1973-87-pre-bent-fuel-lines-and-vacuum-advance-line

My guess. And all we can really do is guess without running his block #s, but I'm thinking they probably reused the lines from the diesel and just installed an one in one out pump. As you know that truck really should have a return line to prevent vapor lock.

 

[SirRobyn0]

I started out using the typical auto parts store stuff, but they really look like crap, especially when you have to use lots of them. By the time were done sorting out your wires it would look like a clown ate a bow of fruity pebbles and threw up in your engine compartment.

I started cutting off the colored plastic and using heat shrink tubing to protect, seal and make it look better. The plastic makes it not crimp as well when using the tool to attach them. You can get the heat shrink tubing in different colors to color code positive and negative if you like also.

The other thing about shrink wrap is it makes a much tighter seal, with no wire exposed to the atmosphere which reduces the risk of the wiring cooper wiring oxidizing and degrading over time. I'm not saying shrink wrap is a requirement, but it does have it's benefits for sure.

 

[SirRobyn0]

I agree and if I may ad something to think about. You have to figure out the math that works for you. In my opinion the price of a cheap fuel pump $21.00 is what you will save by purchasing a better pump to begin with. I can't count how many times I have bought the cheaper model only to have it fail prematurely or not work well enough and then I have to purchase the one I should have bought the first time. The point is, if you buy the cheapest parts you WILL replace them more often and the vehicle will be less dependable. The one below would be adequate if you need to keep it under $100.00 Napa has one for $50.00 model NNP-B0006P. It comes down to gambling, do you want to fix the odds where you get to repeat this adventure in a year or two, or would you like the set the odds so you don't have to do this again for 5 to 10 years. Again, this is just info to help you decide, you do whats best for you.

If it comes down to budget I would use the little pump you have until funds are available to replace and go back to the mechanical pump. But if you can afford the pump, then you don't have to deal with pump wiring. Please do what's best for you and don't let me push you to follow my path if it's not where you want to go. I'll still help even if you don't do it MY WAY. lol

PLEASE check my part numbers for correct fit, I don't know what year motor you have. I guessed it is older due to valve cover bolts.

I agree with the thinking that a cheap pump $21 a cheap regulator $50 is $70 total. I have heard folks have good experiences with the carter pumps, but have no personal experience. I also agree with what Gotyourgoat is saying, the truck if it had come factory with a gas engine it would have had a return line, which would be beneficial in resisting vapor lock. I'm not sure how much Jeff wants to put into this truck or if making it like factory is something he is wanting. Another option is is he doesn't want to mess with a return line right off get one of the single in single out pumps, if he has issues with vapor locking there is a fuel filter he can install after the pump with built in return line port. I'd have to look up the PN for that. It's option, we use to install those on Dodge vans that had vapor lock issues, since they never came with a return line factory. We'd run rubber line for the return BTW, and it was always fine as long as it was secured well to the frame.

 

[jfrancom101]

Looks like a one in one out pump, so this engine was from something older than your truck. Did you find the stock fuel lines? This was originally diesel correct? If the original lines aren't there or they are incompatible with the gas system then this page will help at least show you what you should have. https://www.lmctruck.com/1973-87-chevy-gmc/cc-1973-87-pre-bent-fuel-lines-and-vacuum-advance-line

Yeah I think tha they are the original fuel lines. Thanks for the link. I'll have to look into that before long. Not sure how a return hose would work with two tanks if I eventually ge tthe second tank working too

 

[jfrancom101]

The other thing about shrink wrap is it makes a much tighter seal, with no wire exposed to the atmosphere which reduces the risk of the wiring cooper wiring oxidizing and degrading over time. I'm not saying shrink wrap is a requirement, but it does have it's benefits for sure.

Yeah I ordered that as well. In the future is like to see if they have a battery run heat gun. For now I can use an extension cord but it would be nice for sure.

 

[jfrancom101]

I agree with the thinking that a cheap pump $21 a cheap regulator $50 is $70 total. I have heard folks have good experiences with the carter pumps, but have no personal experience. I also agree with what Gotyourgoat is saying, the truck if it had come factory with a gas engine it would have had a return line, which would be beneficial in resisting vapor lock. I'm not sure how much Jeff wants to put into this truck or if making it like factory is something he is wanting. Another option is is he doesn't want to mess with a return line right off get one of the single in single out pumps, if he has issues with vapor locking there is a fuel filter he can install after the pump with built in return line port. I'd have to look up the PN for that. It's option, we use to install those on Dodge vans that had vapor lock issues, since they never came with a return line factory. We'd run rubber line for the return BTW, and it was always fine as long as it was secured well to the frame.

I'll have to see. I'll probably focus on getting the truck running, but I assume that having a return hose might also help with gas mileage? I'm not actually sure what vapor lock is but it doesn't sound very good. The biggest thing for me is having a truck that will last for a while, but some of the work may need to happen in the summer when I don't need the plow and after a few paychecks

 

[SirRobyn0]

Yeah I think tha they are the original fuel lines. Thanks for the link. I'll have to look into that before long. Not sure how a return hose would work with two tanks if I eventually ge tthe second tank working too

The switching valve has built in ports to switch the return flow to the proper tank.