midnite4x4crew
Registered Member
i am dropping in a motor from an 89 k5 into my 77. i was woundering if i could use my mechanical fuel pump or would i have to drop my tank and put in a sending unit from an 89?
CK5
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fuel pump?
- Thread starter midnite4x4crew
- Start date
well check and see if you got the fuel pump boss with a block off plate. if no plate then the block wont take the pump stuff.
if you can use it then make sure its a flat tappet cam . roller cam would need diffrent parts. but most rollers were efi not carb.
if you can use it then swap your parts over with the push rod.
and you cant just swap in the efi pump sender to a older tank. the efi sender style tanks have a try welder in the bottom to pool the fuel to keep the pump cool and pumping.
now if you need to you can swap newer tank in its place to take the efi sender pump. but if you are running carb and efi pump sender you will need a regulator to set 3-5 psi and also return the extra to the tank.
would be best to get electric carb style pump and mount close to tank and run what ya got .
wow
hope this helps. 
if you can use it then make sure its a flat tappet cam . roller cam would need diffrent parts. but most rollers were efi not carb.
if you can use it then swap your parts over with the push rod.
and you cant just swap in the efi pump sender to a older tank. the efi sender style tanks have a try welder in the bottom to pool the fuel to keep the pump cool and pumping.
now if you need to you can swap newer tank in its place to take the efi sender pump. but if you are running carb and efi pump sender you will need a regulator to set 3-5 psi and also return the extra to the tank.
would be best to get electric carb style pump and mount close to tank and run what ya got .
wow
hope this helps. midnite4x4crew
Registered Member
Its an efi motor im trying to drop in! i have to look at the motor to see if it has a plate.
midnite4x4crew
Registered Member
there is a plate!
If its an EFI, then you will have to use the electric setup. Fuel injectors are not like carbs.
Carbs have the fuel bowl that supplies gas as needed. The carb is pretty laid back as to how it asks for gas.
Injectors have to have gas NOW!!. They cannot wait for the next stroke of a pump. They are only open of a few thousandths of a second. If the gas is not there at the exact same pressure and volume when they open, the engine gets no gas.
This is why an EFI setup supplies the injectors with a large surplus of gas at all times. The excess gets returned to the tank through a regulator.
Your mech pump cannot supply the necessary pressure.
When you add in the necessary pumps, don't forget the inertial switch. It trips and kills power to the pumps when you hit something hard.
Otherwise, you could find yourself trapped in a wreck with a high volume fuel pump squirting gas all over you while a shorted wire keeps sparking as the gas gets closer and closer to it.
J.
Carbs have the fuel bowl that supplies gas as needed. The carb is pretty laid back as to how it asks for gas.
Injectors have to have gas NOW!!. They cannot wait for the next stroke of a pump. They are only open of a few thousandths of a second. If the gas is not there at the exact same pressure and volume when they open, the engine gets no gas.
This is why an EFI setup supplies the injectors with a large surplus of gas at all times. The excess gets returned to the tank through a regulator.
Your mech pump cannot supply the necessary pressure.
When you add in the necessary pumps, don't forget the inertial switch. It trips and kills power to the pumps when you hit something hard.
Otherwise, you could find yourself trapped in a wreck with a high volume fuel pump squirting gas all over you while a shorted wire keeps sparking as the gas gets closer and closer to it.
J.
Really? Coulda fooled me. I just always assumed it was a DOT requirement for all factory vehicles with electric fuel pumps.you've been working on too many Fords...not a GM thing...
I didn't figure any K5s had one stock, since I don't think they came with electric fuel pumps.
I know my Ford truck, Mercedes car, and a friend's Chevy car have one.
Even if they don't, I would consider one. They seem pretty forgiving. I have clipped several trees off at speed with my Ford without tripping mine. Of course, with that massive bumper I don't get a lot of a jolt.
Then again, a friend's car died when a woman talking on a cell phone backed into him in a parking lot.
He called me and I had him check the owner's manual. He found the switch, reset it, and all was well.
J.
I actually used a ford switch on my K5 when I installed an electric fuel pump. Its the only ford part on my chevy. It wasnt too happy about it, but its never tripped no matter how hard I beat the truck. Tap it with a wrench or something and it works. Hope I never need it.
You could go to RockAuto. They sell a "generic" one.
Its used on Fords, but also shows as being used on GM, as well as lots of others. Do a search under switches and relays on any GM truck around about '90 or so.
That way, your K5 would be "unpolluted"<G>.
Like you, I hope I never need one.....
BTW, I have found that lots of things switch off when you tap them with a wrench. Including a large rat.......
J.
Its used on Fords, but also shows as being used on GM, as well as lots of others. Do a search under switches and relays on any GM truck around about '90 or so.
That way, your K5 would be "unpolluted"<G>.
Like you, I hope I never need one.....
BTW, I have found that lots of things switch off when you tap them with a wrench. Including a large rat.......
J.
