Fuel problem on 95 Z-71...need help!
STONECOLD
02-14-2005, 01:17 PM
I have a 95 GMC Z-71 with the 5.7 engine and I'm having trouble with it getting fuel. I've changed the filter and it needed it. I even changed the cap & rotor. I've been told before I change the fuel pump to check the fuel pressure regulator. The injectors are spraying fuel at idle, but it does not increase with me revving the engine. I'm not real experienced with the fuel injection system. Has anyone else had this trouble. Can you give me a tip or two? I cannot get it to a shop to have them pressure check the fuel system or to pressure clean the lines. Help!
2000CAYukon
02-14-2005, 01:42 PM
Can you give more details on what happens when you try to rev the engine? Does it backfire, stall, hesitate, etc?
If the pump was bad and the fuel pressure was too low, it might backfire from running too lean.
On the other hand, if the TPS (Throttle Position Sensor) was bad, it might not do anything when you push the gas pedal.
//2000CAYukon
If the pump was bad and the fuel pressure was too low, it might backfire from running too lean.
On the other hand, if the TPS (Throttle Position Sensor) was bad, it might not do anything when you push the gas pedal.
//2000CAYukon
STONECOLD
02-14-2005, 02:01 PM
When you first crank it, it will idle but slowly drop in RPMs until it dies. When I rev the motor it does not backfire, it just cuts out real bad. The first time I felt it, it seemed to just cut out going down the road. Then it started running bad, 20 mph top speed. It cuts out bad, but never back firing. It also does not start as quick on the turnover.
2000CAYukon
02-14-2005, 05:20 PM
Unfortunately, it is touch to test the fuel pressure on the TBI trucks since there is no service port on the fuel rail. Most of the tools I have seen install in place of the fuel filter so that a gauge can be attached.
Pressure should be 9 - 13 PSI at idle. Under a load is should not drop below 9.
//2000CAYukon
Pressure should be 9 - 13 PSI at idle. Under a load is should not drop below 9.
//2000CAYukon
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