95 3100 Starting/acceleration problems
Posted: Tue Sep 02, 2014 11:04 pm
My DD 1995 3100 stock motor.
Starting having problem accelerating away from stop lights and signs. It would sputter and then kick in. A few times backing up it would stall out. Well after leaving the hospital last night I went to start her up and she was misfiring and sputtering. I got about 4 feet and she died. I got under the hood and pushed on the fuel pressure port and had gas. I also checked spark. While trying to crank it would sputter and die. I never did smell raw fuel. I checked some connections and such. As I waited for my dad to bring me the scanner and some tools I tried starting it again and it took off and I drove it home no problems.
Today. I went to the gym. No problems. After the gym started acting up again, but she started and sputter and such. When going into gear it really starts missing and choking out sometimes die. Basically when it has a load. After a little it would run decent at a higher idle. So I drove home popping it in N when at a stop. Once at my garage I changed out the spark plugs and wires. Changed oil. After that it still was acting up. I really didn't think that was going to fix it but they looked sad. So I checked the fuel pressure at the rail and prime pump pressure runs 20 Psi. I forgot when it starts what it runs at. I don't think it's much higher. I was being rushed by darkness. I started to troubleshoot low fuel pressure. Fuel filter is about a year old, but I am thinking about replacing it anyways. I pulled the fuel rail off and check for leaking injectors. All good. The GM manual says it should prime to 41 to 47 psi. I did the trouble tree that included blocking off the return line to the tank and putting power to the test port. 20Psi. I ohmed out the wire going to the pump to a ground and got 14.5. I have a used pump that came out of a Z26 and that ohmed out 20K. I also checked Active and history faults and nothing was there. Well some EGR faults.
So I guess is it poss. for a fuel pump to be weak. I have always seen them fail or work. Any ideas. I think 41Psi seems high but that is what the book says.
Starting having problem accelerating away from stop lights and signs. It would sputter and then kick in. A few times backing up it would stall out. Well after leaving the hospital last night I went to start her up and she was misfiring and sputtering. I got about 4 feet and she died. I got under the hood and pushed on the fuel pressure port and had gas. I also checked spark. While trying to crank it would sputter and die. I never did smell raw fuel. I checked some connections and such. As I waited for my dad to bring me the scanner and some tools I tried starting it again and it took off and I drove it home no problems.
Today. I went to the gym. No problems. After the gym started acting up again, but she started and sputter and such. When going into gear it really starts missing and choking out sometimes die. Basically when it has a load. After a little it would run decent at a higher idle. So I drove home popping it in N when at a stop. Once at my garage I changed out the spark plugs and wires. Changed oil. After that it still was acting up. I really didn't think that was going to fix it but they looked sad. So I checked the fuel pressure at the rail and prime pump pressure runs 20 Psi. I forgot when it starts what it runs at. I don't think it's much higher. I was being rushed by darkness. I started to troubleshoot low fuel pressure. Fuel filter is about a year old, but I am thinking about replacing it anyways. I pulled the fuel rail off and check for leaking injectors. All good. The GM manual says it should prime to 41 to 47 psi. I did the trouble tree that included blocking off the return line to the tank and putting power to the test port. 20Psi. I ohmed out the wire going to the pump to a ground and got 14.5. I have a used pump that came out of a Z26 and that ohmed out 20K. I also checked Active and history faults and nothing was there. Well some EGR faults.
So I guess is it poss. for a fuel pump to be weak. I have always seen them fail or work. Any ideas. I think 41Psi seems high but that is what the book says.