Fuel Pump not engaging
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Fuel Pump not engaging
I just swapped out a the original '86 302 for a '91 302. I haven't had the joy of hearing it start yet. When accessory power is ON, The fuel pump doesn't come on. I have a dual tank. The fuel pump on the the frame under the driver door is the one I am referring to. I disconnected the fuel pump and connected it straight to the battery. It worked like a champ. So I put it back down there and hooked it up to another accossory plug with two wires and when I turn the Accessory Power ON, the fuel pump engages, but doesn't shut off. I'm thinking that it might be the relay switch, But I do not know where that is. While it was hooked up to this plug and it was running, I tried to start, but still no Joy. It has only been about 3 1/2 weeks since the last time the engine ran before the swap. All the engine will do, is turn. The firing order is good. New plugs in it. I don't know what in the heck the deal is.
Also, I have about 12V running to the coil from the wires, but when hooked up to the coil, I just have about 10V. I don't think any of this is my problem.
Also, I have about 12V running to the coil from the wires, but when hooked up to the coil, I just have about 10V. I don't think any of this is my problem.
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From: Virginia
In the picture above is the plug that you use to plug in the code reader(the one with the angled corners). On that plug there should be a tan/lightgreen wire. With the key on, if you take and jam a wire into that part of the plug with the tan/lightgreen wire, and then touch the other end of this wire to ground, the pump should run. This will tell you if the fuel pump relay is working or not.
Did you use all the wiring and sensors from the 86? In some ways the 86 was wired a little bit different that the later models. So if you use the 86 cab wiring with the later model engine wiring, there could be conflicts.
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Thanks,
I'll have to give that a try whenever I get back to the garage. I'm working this week and it will be about a week or two before I can get in there. I'm not sure about what you meant about the "body grounds" I've got the battery gets grounded right to the block and to the sylinoid. I'll try the jumper thing next. But I just wired the pump straight to a battery charger to get it kickin, but still no start. The only time that it tried to start was when I put some gas in the intake. So I figured, it's not getting any fuel. I just checked on the side of the filter between the filter and fuel rail, no fuel pumping out, so I checked on the input side. No fuel still, So I'm guessing the fuel pump isn't working properly. And the device inside of it doesn't engage to cut it off because the system doesn't get pressurized.
I'll have to give that a try whenever I get back to the garage. I'm working this week and it will be about a week or two before I can get in there. I'm not sure about what you meant about the "body grounds" I've got the battery gets grounded right to the block and to the sylinoid. I'll try the jumper thing next. But I just wired the pump straight to a battery charger to get it kickin, but still no start. The only time that it tried to start was when I put some gas in the intake. So I figured, it's not getting any fuel. I just checked on the side of the filter between the filter and fuel rail, no fuel pumping out, so I checked on the input side. No fuel still, So I'm guessing the fuel pump isn't working properly. And the device inside of it doesn't engage to cut it off because the system doesn't get pressurized.
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From: Easton,Ks
The body must be grounded for the fuel pumps to work. I just ran into this again this week end, put in new crate engine in an 88 and the fuel pumps would not work until I ran an extra ground from the neg side of the battery to a body screw. Used a heavy wire, never did see a body ground strap while removing the engine but the pumps did not work until I ran the wire and they worked before the change out. There were other things that would not work right also.
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From: Virginia
I think the factory did have a ground from the negative to an important computer ground somewhere on the fender. Several times on here some guys had a no start condition and a little connector in that ground was corroded.
You may also want to see if you have any spark. If there are no pulses from the dist module going to the computer, the computer will not turn the fuel pump on, although the fuel pump should come on for a couple of seconds when you first turn the key.
Try the grounding thing on the plug first though. That will tell you a lot if the fuel pump does or doesn't run.
You may also want to see if you have any spark. If there are no pulses from the dist module going to the computer, the computer will not turn the fuel pump on, although the fuel pump should come on for a couple of seconds when you first turn the key.
Try the grounding thing on the plug first though. That will tell you a lot if the fuel pump does or doesn't run.
