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How many people have put an old fashioned carb on a motor that used to have an EFI throttle body???


I have a 1989 Chevy Crew Cab Dually with a 454. The thing has had a surge in it that will not go away. Tried everything... Cant find what is causing it.. Only thing I can think of is the throttle body is screwed up.. It runs hotter than hell too...


Motor is almost new... And it did it on the old motor too....


What do I need to do to convert the truck over to a regular style carb?




Vanilla
 

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A sparkplug wire dropping a hole will cause a bigtime surge, i had that problem.
 

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Discussion Starter · #3 ·
Those are new.... Everything was new when we put the motor in..... Thing has been pissing me off... about ready to just take it out in the country and burn it to the ground....




Vanilla
 

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1989 it probably has a turbo 400, so just bolt on a intake and carb do away with the distributor and put a HEI, that should solve all your problems.
 

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the engine will run fine with the carb and intake. (personally I swapped cams for this). I got rid of all the sensors as they were not needed. I also bought the old summit special HEI distributor.
 

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Just set it aside incase you ever wanted to put it back. The only wire you will need is the + wire on the coil, and one last detail I forgot is that you will have to drop your gas tank and remove the pump and replace it with a 3/8 steel hose attached with small rubber hose, (2) 3/8 hose clamps. Your fuel pump can just be a holley red or something like that, because the block may have a location to put a fuel pump, but chances of your camshaft having a fuel pump lobe are slim to none.
 

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How many people have put an old fashioned carb on a motor that used to have an EFI throttle body???


I have a 1989 Chevy Crew Cab Dually with a 454. The thing has had a surge in it that will not go away. Tried everything... Cant find what is causing it.. Only thing I can think of is the throttle body is screwed up.. It runs hotter than hell too...


Motor is almost new... And it did it on the old motor too....


What do I need to do to convert the truck over to a regular style carb?




Vanilla
HEY HEY HEY... Vanilla... Calm down... I did drivability for Chevrolet for many, many years. Let me assure you, there's nothing in that throttle body that will make it surge.. You need to hook up a scan tool to it, and see what's goin on with all the other parameters...
Especially the electronic spark timing, and the coolant sensor circuit.
Find an old timer like me that has alot of experience with these systems, and has access to a scan tool.
Converting it over to a carb is more than you might think... It also wont run as good, and you wont be able to afford the fuel required..
Dont run away from it... FIX it.. Call or PM if I can help..
Respectfully...
Denny Savage
 

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Discussion Starter · #10 ·
Denny,


Give me your number or give me a buzz.... 217-202-1246...


Figured since today is my birthday, we would have a nice dually bonfire..... may even throw in a 593 BBC for good measure... but thats another story....




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If they both have fuel pumps in them yes, (which more than likely they do). Your fuel tank selector shouldn't be effected by it. We just did this same conversion on one of my buddy's 87 1/2 with a small block 350. To top it off the fuel mileage isn't too much different.
 

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HEY HEY HEY... Vanilla... Calm down... I did drivability for Chevrolet for many, many years. Let me assure you, there's nothing in that throttle body that will make it surge.. You need to hook up a scan tool to it, and see what's goin on with all the other parameters...
Especially the electronic spark timing, and the coolant sensor circuit.
Find an old timer like me that has alot of experience with these systems, and has access to a scan tool.
Converting it over to a carb is more than you might think... It also wont run as good, and you wont be able to afford the fuel required..
Dont run away from it... FIX it.. Call or PM if I can help..
Respectfully...
Denny Savage
x2. It's more than likely a simple sensor gone bad or a wiring circuit problem. The old TBI system is very reliable once you get it going. ;) I was also a GM dealer tech back in the day.
 

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If injectors are not new, have them cleaned or replace w/ new ones.

What's the fuel pressure?
 

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i just did a 350tbi swap to454carb on a 93 c-1500. i ran the stock elec. fuel pump with over 200k on it.(604 pump gas hp at the wheels with nos on our chassis dyno and the the pump kept up. ) . just put in a regulator to lower fuel pressure. we also used the return line to keep the pump cool. i would use the stock pump. a lot less work.
 

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How many people have put an old fashioned carb on a motor that used to have an EFI throttle body???


I have a 1989 Chevy Crew Cab Dually with a 454. The thing has had a surge in it that will not go away. Tried everything... Cant find what is causing it.. Only thing I can think of is the throttle body is screwed up.. It runs hotter than hell too...


Motor is almost new... And it did it on the old motor too....


What do I need to do to convert the truck over to a regular style carb?




Vanilla
Screw it just buy mine!
 

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Is this a part thottle surge ? Try disconnecting the EGR valve vacum line.


How many people have put an old fashioned carb on a motor that used to have an EFI throttle body???


I have a 1989 Chevy Crew Cab Dually with a 454. The thing has had a surge in it that will not go away. Tried everything... Cant find what is causing it.. Only thing I can think of is the throttle body is screwed up.. It runs hotter than hell too...


Motor is almost new... And it did it on the old motor too....


What do I need to do to convert the truck over to a regular style carb?




Vanilla
 

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I had that problem on an older caddy of mine, There was a small rubber elbow on the TB that fed the MAP sensor, The dammed elbow was rotted on the bottom and leaking like crazy. I changed that hose and it ran fine, That's after 3 shops spend close to a grand on it tryin to fix it by playing parts changers.
 
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