Notices
S-10 & Blazer 1982-2005
The S-10 and Blazer was arguably the most versatile and accessorizable mid-size truck and SUV on the market.
Platform: S/T-series & GMT 330

tbi to carb 4.3

Old March 23rd, 2019, 1:03 PM
  #1  
CF Junior Member
Thread Starter
 
Join Date: Mar 2019
Posts: 31
Default tbi to carb 4.3

I am converting a 1990 4.3 to a carb, I am installing a new hei distributor with built in coil, using a motorcraft 2100 two barrel carb, i havent completed it yet but its getting close, i am installing a 4.5-6 lb. psi pump below the tank, I cut the red wire to the pump to use for the new pump. I notice the other day after disconnecting the sensors and the distributor that when i turn the key on the gas guage goes all the way to full and i know it has a little less than half a tank, i dont know what caused this, also the old distributor had a plug with 4 wires plugged into the distributor as well as the hot wire for the coil on the other plug. I am wondering if there is anything in those 4 wires that need attention that might be affecting anything, the oil pressure unit I was able to leave in place just had to turn it a bit. would anyone know why the gas gauge did that , or about the plug with the 4 wires that went to the old distributor, they werent the power wires feeding the distributor, would appreciate any thoughts on this as i am not an expert on this stuff.
charlie2sods is offline  
Old March 23rd, 2019, 1:26 PM
  #2  
I'm here for the party
 
Irish_alley's Avatar
 
Join Date: Feb 2019
Location: Maryland
Posts: 386
Default

could that little red wire actually been pink with maybe a black stripe? if so thats your sending unit wire and the reason why your gauge is pegging out. i cant tell you what color your fuel pump wire is but im sure there should only be one or two more wires to choose from. the other wires on the dis. should of went to the ecm to tell the injectors to "fire"

Last edited by Irish_alley; March 23rd, 2019 at 8:17 PM.
Irish_alley is offline  
Old March 23rd, 2019, 4:20 PM
  #3  
CF Junior Member
Thread Starter
 
Join Date: Mar 2019
Posts: 31
Default

I just went out and checked that wire it is pink but no black stripe, you could be right I may have cut the wrong wire, the other one i think is white, it could be the power wire to the pump, i will check it out tomorrow and get back with you, thanks for replying
charlie2sods is offline  
Old March 23rd, 2019, 6:12 PM
  #4  
I'm here for the party
 
Irish_alley's Avatar
 
Join Date: Feb 2019
Location: Maryland
Posts: 386
Default

i think the black stripe was dependent on the year
Irish_alley is offline  
Old March 23rd, 2019, 8:14 PM
  #5  
CF Beginner
 
Join Date: Mar 2019
Posts: 2
Default

There should be 4 wires to the sending unit. I'm not versed on the colors, but the 2 thicker wires go to the pump, the 2 thinner wires go to the gauge. If only 3 then the pump and level sender use a common ground.

Either way if you are using an external pump you should remove the internal pump and replace it with a hose to reduce wear on the external pump. The internal pump also could lock up over time causing no fuel flow. overall better to be rid of it sooner rather than later.
efilnikufecin is offline  
Old March 23rd, 2019, 8:47 PM
  #6  
I'm here for the party
 
Irish_alley's Avatar
 
Join Date: Feb 2019
Location: Maryland
Posts: 386
Default

you might be able to find the wire harness http://www.73-87chevytrucks.com/tech...ing_Manual.pdf its for a 91 v series truck but it should be about the same
Irish_alley is offline  
Old March 24th, 2019, 10:25 AM
  #7  
CF Junior Member
Thread Starter
 
Join Date: Mar 2019
Posts: 31
Default

the pink wire was the guage, i reconnected it and it works fine, and there is no voltage to either wire, there are only two wires, one of the plugs that was unpluged under the hood must have cut the power to the pump,
charlie2sods is offline  
Old March 24th, 2019, 1:49 PM
  #8  
CF Junior Member
Thread Starter
 
Join Date: Mar 2019
Posts: 31
Default

i think im getting closer to figuring this stuff out, im not familiar with this 2100 ford carb, there are three vacuum stubs on it, one small one in front of the choke, which i assume goes to the vacuum advance on the distributor, and then there is one about a 1/4 in coming out from under the round plate on top of the carb that accesses where the air filter is, and one 3/8 in one on the bottom right hand back of the carb, can someone steer me right on what these are and where they go to, would appreciate it , thanks

Last edited by charlie2sods; March 24th, 2019 at 2:59 PM.
charlie2sods is offline  
Old March 24th, 2019, 3:20 PM
  #9  
CF Veteran
 
oilcanhenry's Avatar
 
Join Date: Oct 2017
Location: USA
Posts: 1,316
Default

Originally Posted by charlie2sods View Post
i think im getting closer to figuring this stuff out, im not familiar with this 2100 ford carb, there are three vacuum stubs on it, one small one in front of the choke, which i assume goes to the vacuum advance on the distributor, and then there is one about a 1/4 in coming out from under the round plate on top of the carb that accesses where the air filter is, and one 3/8 in one on the bottom right hand back of the carb, can someone steer me right on what these are and where they go to, would appreciate it , thanks
Curious why you want to change out a TBI for a carburetor. I am GLAD carbs are almost gone, even in motorcycles..
oilcanhenry is offline  
Old March 24th, 2019, 5:16 PM
  #10  
CF Junior Member
Thread Starter
 
Join Date: Mar 2019
Posts: 31
Default

i will soon be 74, i want an old school truck that I understand and can work on, thats the shortest best answer i can give
charlie2sods is offline  

Thread Tools
Search this Thread
Sponsors

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: