1987 TBI fuel pump issue

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Jiblackledge

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Butte, Montana
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James
Truck Year
1987
Truck Model
R20
Engine Size
350
I have a 1987 chevy R20 with the 350 TBI and dual tanks, the right tank fuel pump was bad, I ordered a new one and installed, drove the truck and during hard acceleration it seams as though it is not getting enough fuel, when I swap to the left tank it does not do that and I can get in it and it will accelerate with no issues, I'm wondering if the new fuel pump can not keep up and should I replace it with another. Aslo the truck is completly stock.
 

Ricko1966

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1975
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c20
Engine Size
350
I have a 1987 chevy R20 with the 350 TBI and dual tanks, the right tank fuel pump was bad, I ordered a new one and installed, drove the truck and during hard acceleration it seams as though it is not getting enough fuel, when I swap to the left tank it does not do that and I can get in it and it will accelerate with no issues, I'm wondering if the new fuel pump can not keep up and should I replace it with another. Aslo the truck is completly stock.
Make sure none of the hoses got kinked or crimped,try running it with no gas cap. Post back.
 

Jiblackledge

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1987
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R20
Engine Size
350
I did purchase a delphi pump and I was very careful to make sure the hoses were not kinked or crimped because the tank has to be dropped and I also lifted the bed off so that I could check the hoses after I put the tank back in. So this is why I'm a little confused. The left side no issue but the right side with new pump it has issues.
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Redfish

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1987
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V1500
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350/5.7
Is the switching valve working properly? They do go bad eventually.
 

Jiblackledge

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1987
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I think it is, it does switch back and forth between the tanks, and the truck does cruise when the right tank is chosen, its when I try to accelerate to pass or just want to get on it, it acts as if it is not getting enough fuel. How would I check the switch.
 

Ricko1966

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I think it is, it does switch back and forth between the tanks, and the truck does cruise when the right tank is chosen, its when I try to accelerate to pass or just want to get on it, it acts as if it is not getting enough fuel. How would I check the switch.
I hate to tell you this there is no easy diagnoses for this. You could have poor contacts in the switching,you could have a switching valve that leaks internally,you could have a bad connection at the tank or at the pump. First I think I'd wiggle my tank connections,then bypass the valve. Then I'd bypass electric switch to tank then I'd drop the tank and inspect for a bad connection,trash in the tank,a broken baffle.
 

gmbellew

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also check the fuel pressure on that pump....
 

Ricko1966

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I did purchase a delphi pump and I was very careful to make sure the hoses were not kinked or crimped because the tank has to be dropped and I also lifted the bed off so that I could check the hoses after I put the tank back in. So this is why I'm a little confused. The left side no issue but the right side with new pump it has issues.
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also check the fuel pressure on that pump....
Check pump pressure at the tank. A switching valve that's bypassing will show low pressure,but not the pumps fault
 

Jiblackledge

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Thanks for the advice, I'll give that a try and see what I get for pressure.
 

Rusty Nail

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350sbc
Yeah.Whack on it with a hammer.A little bit.

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Jiblackledge

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James
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1987
Truck Model
R20
Engine Size
350
Just a little update, I removed the shield from the selector switch, and it was leaking, so I have one coming and going to give that a shot before dropping the tank and changing the pump.
 

Jiblackledge

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1987
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R20
Engine Size
350
I changed the fuel tank selector valve and the problem is fixed, took the truck out for a test ride and no hesitation or stumbling, just press the accelerator pedal and it will get up and go. Thanks for the advice and I hope that this can help someone in the future.
 

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