1989 GMC C2500 Sputtering problems

[gotbat]

my truck just started doing this a couple days ago... the fuel injectors make a loud and random buzzing noise.. i replaced them and no change... i woke up this morning and went out to start it and it starts for about 2-3 minutes... then sounds like it floods or just boggs down, i dont get it... it completely turns off.. now its undrivable, ive had no change at all. so far ive replaced fuel injecters, fuel filter, ive added fuel treatment also. help!!!

[linuxmann]

Are you sure it is bogging/dieing because of too much fuel? I ask because low fuel pressure is very common on these. I would do a pressure check. Check the idle air control motor and the pressure regulator. These are common parts to fail.

[Ford4x4Chik27]

Yeah your fuel pump too

[DodgeChick]

I 2nd the fuel pump check...

[932500]

The fuel pressure check is to check the fuel pump and the pressure regulator. Most of the time when the fuel pump fails it fails completely, but not always.. Should be 9-13 psi. Another thing to check is a check on the temperature sensor. Now I know you think it sounds dumb, but if it isnt working correctly, after a few minutes of running, it senses the motor is running real cold and floods out the fuel air mixture and kills the motor

[Truck_Man]

Originally Posted by 932500

The fuel pressure check is to check the fuel pump and the pressure regulator. Most of the time when the fuel pump fails it fails completely, but not always.. Should be 9-13 psi. Another thing to check is a check on the temperature sensor. Now I know you think it sounds dumb, but if it isnt working correctly, after a few minutes of running, it senses the motor is running real cold and floods out the fuel air mixture and kills the motor

Check the owner manual on fuel pressure, i think it is suposed to be higher than 9-13. I know on my olds 98 they said something like 40 psi thats steping down on it ideling is lower. Find out fromt he repair manual though as all cars and trucks are different.

9-13 sounds like fuel pressure for a vehicle with a carburator, yours would have fuel injection witch requires alot more for the injectors to work right.

[chevyguy]

Look at the year there truck man, If it was 1996 or newer then you are correct, but this is older throttle body technology, As ststed in the chevrolet service manual, Feul pressure check should reveal fuel pressure between 9-13 psi... As for carbeurated fuel pressure, 8 should be the max unless you have alot of carb work done.otherwise your fuel pressure pushes the float valve open.

[Truck_Man]

Originally Posted by chevyguy

Look at the year there truck man, If it was 1996 or newer then you are correct, but this is older throttle body technology, As ststed in the chevrolet service manual, Feul pressure check should reveal fuel pressure between 9-13 psi... As for carbeurated fuel pressure, 8 should be the max unless you have alot of carb work done.otherwise your fuel pressure pushes the float valve open.

Yeah, thats why i told him to check the manual, I had an escort with the throttle body injection, a mechanic i took that too at one time said that was normal at 18 for idle and would go up to around 40 as you rev it. It just depends on the setup and what the manufacture recomends. Some of these mechanic i dont know if i trust though.

[chevyguy]

Originally Posted by 932500

The fuel pressure check is to check the fuel pump and the pressure regulator. Most of the time when the fuel pump fails it fails completely, but not always.. Should be 9-13 psi. Another thing to check is a check on the temperature sensor. Now I know you think it sounds dumb, but if it isnt working correctly, after a few minutes of running, it senses the motor is running real cold and floods out the fuel air mixture and kills the motor

This is good info. Believe this fuel pressure .9-13 is correct for your year. If anyone tells you different I can scan the G.M. tech service manual and post it here if needed. Hope this helps, I am just trying to point you in the right direction.

[Truck_Man]

Originally Posted by chevyguy

This is good info. Believe this fuel pressure .9-13 is correct for your year. If anyone tells you different I can scan the G.M. tech service manual and post it here if needed. Hope this helps, I am just trying to point you in the right direction.

Very correct, for anybody reading this always go by what the manufacture recomends as things change between different makes of vehicles and different setups.