88 350 TBI losing power

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RustyNail351

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Location
CT
First Name
Rusty
Truck Year
1988
Truck Model
R2500
Engine Size
350
Got an 88 R2500 with the 350 TBI having power issues. Already been through having to change the coolant temp sensor and then the EGR valve after it got stuck open. Changed fuel filter and cap and rotor last year which seemed to fix it before parking it for the winter. Started acting up again but not as bad as before. After warming up and driving for a bit giving it more than 1/4 throttle it starts falling on its face, any more and it completely dies out like it's not getting enough gas let up on the throttle and it catches again but still can't give it more than 1/4. So I'll push the clutch in shut the key off turn it back on and pop start it and then can put it right to the floor and it'll run great for a while. Check engine light comes on when it happens and then goes out after restarting but I haven't had a chance to scan it yet. Adapter coming for the scanner and plugs and wires coming as well but looking for a direction to look in the meantime.
 

gmbellew

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Kansas city
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glen
Truck Year
1990
Truck Model
suburban 1500
Engine Size
350
you can check stored codes by jumping A and B on the ALDL port and turning key to on. it will flash 12 three times and then flash stored codes (up to like 30 starts ago).

I'd also check the fuel pressure.

the data stream from ALDLDroid or a scanner will help diagnose more.
 

fast 99

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Spokane, Washington
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Brian
Truck Year
81,85
Truck Model
K20
Engine Size
350
Have seen A LOT of aftermarket distributor caps that cross fired. Only buy Delphi, Delco or GM. They are expensive but I have dealt with countless drivability issues caused by other brands. They leak within the cap, it's not visible.
 

Scott551

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Ocean City
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Scott
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90
Truck Model
k1500
Engine Size
350
Got an 88 R2500 with the 350 TBI having power issues. Already been through having to change the coolant temp sensor and then the EGR valve after it got stuck open. Changed fuel filter and cap and rotor last year which seemed to fix it before parking it for the winter. Started acting up again but not as bad as before. After warming up and driving for a bit giving it more than 1/4 throttle it starts falling on its face, any more and it completely dies out like it's not getting enough gas let up on the throttle and it catches again but still can't give it more than 1/4. So I'll push the clutch in shut the key off turn it back on and pop start it and then can put it right to the floor and it'll run great for a while. Check engine light comes on when it happens and then goes out after restarting but I haven't had a chance to scan it yet. Adapter coming for the scanner and plugs and wires coming as well but looking for a direction to look in the meantime.

i can help you , i make custom programmed chips for the 87-95 tbi, can also delete egr entirely
 

fast 99

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Brian
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81,85
Truck Model
K20
Engine Size
350
i can help you , i make custom programmed chips for the 87-95 tbi, can also delete egr entirely

FYI
Although most areas no longer do emissions tests on older vehicles, EPA has been going after reprogammers.
 

Ricko1966

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kansas
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Rick
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1975
Truck Model
c20
Engine Size
350
Working EGR has absolutely no downside and definite positive attributes.
 

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