I recently installed a walbro pump in my 2000 trans am. When i took it out for a drive it started running terrible. In the low rpms it would spit and sputter...wouldnt clear up until around 3k rpm. I let it idle in the driveway and the fumes were so strong they burned my eyes. Fuel pressure is holding steady at 64psi. I thought that was a little high considering stock is 58. My question is, has anyone else run into this issue? Does the walbro run a tad higher pressure than the factory pump?

 

I am fighting the same issues with my 6.0. Have't quite figures it out. My pressure is high 50s low 60s. Might end up getting an adjustable fuel pressure regulator.

 

That is exactly what mine is doing. I actually searched and read though your thread lol. Didn't want to steal your thread. I'm thinking retuning it will help.

 

computer has to learn out the new fuel you are pushing through it.

also if you happened to unhook the battery while doing the tank, it likely reset the computer and it is trying to learn it all over again anyways.

 

Bump....

 

63 is normal. It shouldn't cause a rich condition at all much less sputtering. Maybe if the PCM had learned to adjust for a very lean condition of a bad fuel pump before the switch. But I don't think even a 10 psi increase in pressure would cause it to run that bad. And it would learn the new AFR in a few minutes and clear up.

 

i am fixing to put a 255 in my car my question and it might be a stupid one but do u have to get ur car tuned if all u have done is a fuel pump as the only upgrade u have done to it ???

 

As long and the fuel pressure stays within 5% or so of 58 psi at the rail no tuning is required.