I am having lots of problems getting my 1996 chevy 3500 with the 5.7 running correctly.
About 4 months ago the truck started to run rough. I found out I had low fuel pressure, and that the fuel pressure would drop off almost instantly once the key was shut off. I replaced the fuel pump with a Delphi brand pump. And I also replaced the fuel filter.
After the fuel pump change, the truck still ran rough. So I brought it to a mechanic to diagnose. They did a fog test and made sure I had no vacuum leaks. They also said my sensors were working correctly. Then they put a camera down and saw that a few of my injectors were not working correctly. My LTFTs were basically pegged. So I parked the truck for a while and just this last week I replaced the Injectors with standard brand MPFI. While I was in there, I saw that my plastic distributor was cracked, so I also replaced the distributor with an aluminum body, changed out my plugs and wires too.
After changing the spider injectors, FPR, distributor, cap, rotor, and plugs. The truck is still running rough and throttle response is horrible. I did check the CMP with my scan tool and it is set at 0° when the truck was above 1000rpm. At idle my LTFT bank 1 is at 25%, bank 2 is at 20%. At about 1200rpm bank 1 and bank 2 are around 18%. it says my air fuel ratio is 14.7:1. Seems very lean.
I am just not sure where else to look. The truck is not throwing any codes, but i have not driven it more than around the block a couple times. Does anyone have suggestions on where I can start troubleshooting?
About 4 months ago the truck started to run rough. I found out I had low fuel pressure, and that the fuel pressure would drop off almost instantly once the key was shut off. I replaced the fuel pump with a Delphi brand pump. And I also replaced the fuel filter.
After the fuel pump change, the truck still ran rough. So I brought it to a mechanic to diagnose. They did a fog test and made sure I had no vacuum leaks. They also said my sensors were working correctly. Then they put a camera down and saw that a few of my injectors were not working correctly. My LTFTs were basically pegged. So I parked the truck for a while and just this last week I replaced the Injectors with standard brand MPFI. While I was in there, I saw that my plastic distributor was cracked, so I also replaced the distributor with an aluminum body, changed out my plugs and wires too.
After changing the spider injectors, FPR, distributor, cap, rotor, and plugs. The truck is still running rough and throttle response is horrible. I did check the CMP with my scan tool and it is set at 0° when the truck was above 1000rpm. At idle my LTFT bank 1 is at 25%, bank 2 is at 20%. At about 1200rpm bank 1 and bank 2 are around 18%. it says my air fuel ratio is 14.7:1. Seems very lean.
I am just not sure where else to look. The truck is not throwing any codes, but i have not driven it more than around the block a couple times. Does anyone have suggestions on where I can start troubleshooting?
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