Hey there. Just got a 85 Jimmy. Guy told me it needed a flywheel and then I found two rods in the oil pan . Also had the carb just sitting on the intake. Said it was 327. It’s not. Anyways. The motor has a mechanical fuel pump. But there are wires coming from the fuel talk. Is that right? I thought it was usually one or the other. Also are there any good resources for correctly wiring up the motor? I’m having one built. And there are many wires just laying in the dog house or they are snipped. How to I k ow what’s what! Any and all help would be great. Thank you.
CK5
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Fuel pump confusion.
- Thread starter Bcwkyle
- Start date
Wires to the tank could just be the sending unit.
I'm not sure when they started TBI in the Jimmy's, or if they used an electric pump on the electronic quadrajet carbs.
My 85 big block was electronic carb. But I never changed a fuel pump that I remember. I'd think the carb ones would be mechanical FP.
I'm not sure when they started TBI in the Jimmy's, or if they used an electric pump on the electronic quadrajet carbs.
My 85 big block was electronic carb. But I never changed a fuel pump that I remember. I'd think the carb ones would be mechanical FP.
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- Mar 3, 2000
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Welcome! The wires should just be sending which connects to gas guage. TBI was later like 87 or 88.
Wiring diagrams are in most manuals such as Haynes or you can order them, I am sure someone on here would have one or you can order a factory service manual.
Wiring diagrams are in most manuals such as Haynes or you can order them, I am sure someone on here would have one or you can order a factory service manual.
Welcome to CK5 @Bcwkyle
If there are only 2 wires at tank, then sender, brown wire, for gauge. Black wire is the ground should have a ring terminal bolted to a cross member near tank, axle side. Your brief description of your truck tells me it probably has had much stuff changed and we can't assume anything. Someone may very well have installed a fuel injection tank with an in tank pump. A mechanical pump with a carb is perfectly do able, but we will need to confirm which tank is in the truck.
Your may have originally come with Computer Command Control fuel and emission system. Which had computer controlled carburetor, and electronic controlled spark timing distributor. This system worked ok when new, and knowledgeable tech could maintain, repair, and parts were readily available. If this the case you may want to revert back to standard HEI and Q jet. Many of the under hood wires will no longer be needed.
We can help you sort it out. Will take a few posts and I encourage premium member ship here, this will allow you see any and all photos posted. Much easier to mark up a diagram and post up then type out an understandable description.
If there are only 2 wires at tank, then sender, brown wire, for gauge. Black wire is the ground should have a ring terminal bolted to a cross member near tank, axle side. Your brief description of your truck tells me it probably has had much stuff changed and we can't assume anything. Someone may very well have installed a fuel injection tank with an in tank pump. A mechanical pump with a carb is perfectly do able, but we will need to confirm which tank is in the truck.
Your may have originally come with Computer Command Control fuel and emission system. Which had computer controlled carburetor, and electronic controlled spark timing distributor. This system worked ok when new, and knowledgeable tech could maintain, repair, and parts were readily available. If this the case you may want to revert back to standard HEI and Q jet. Many of the under hood wires will no longer be needed.
We can help you sort it out. Will take a few posts and I encourage premium member ship here, this will allow you see any and all photos posted. Much easier to mark up a diagram and post up then type out an understandable description.
Very helpful thank you! So there is currently an HEI on my motor. But that thing is TOAST. So I’m weighing my options on what to do for a motor. Can anyone tell me what motor years fit in my Jimmy? Will any SBC fit? I will be doing some off roading as well and I told that a smaller cam for more torque is the way to go. I can swap parts all day long. But I’m not a mechanic. I was a body guy and now I’m a woodworker. So any advice would be great. Thanks!
Got it. Thank you!
I’ve seen a lot of things about heads pairing with blocks. I have a set of 882 heads. Is there a block I should be looking for for these? I have trouble understanding why it matter.
don't spend any money those 882's they a crack waiting to happen if not cracked all ready. A 1 piece rear main seal and roller cam block are what you want for your base block. These are 87 up generally, for both the rear main and roller lifters. A nice set of aftermarket heads won't cost much more then machining a set of old factory heads, and they will out perform the factory stuff all day. You will want to shoot for @9.5 to 1 compression ratio. Whether or not you stroke a sbc.
You also need to decide what size tires gears and transmission you wish to use, so we can get an idea of rpm range for various driving situations.
A big block can compensate for taller gears with bigger tires better than a sbc will, both will get about the same mpg in a lifted square.
You also need to decide what size tires gears and transmission you wish to use, so we can get an idea of rpm range for various driving situations.
A big block can compensate for taller gears with bigger tires better than a sbc will, both will get about the same mpg in a lifted square.
