Quote:
Originally posted by WA2FAST
In reply to your last attempts..
Disconnecting the fmu vacume line takes out the possibility that the line could have been hooked up wrong in any way.
Adjusting the regulator would be the next step... you said you adjusted it all of the way out... did you try the other way?
Rotating the MAF has nothing to do with fuel pressure... fuel pressure is strictly mechanical.
Again, fuel pressure is mechanical. Resetting the computer would do nothing.
You having the FMU hooked up to the vacume tree is just fine.
Kinks in the vacume line wouldn't make it sit at 100psi. all of the time, but always good to check that anyway.
I'm still trying to figure out why you would "hammer it" when it is working as odd as it is, but whatever... either way, it sounds to me that something is hooked up backwards or simply malfunctioning.
The way that the regulator works is it lets a certain amount of fuel through the return line back into the tank and that is what creates the pressure. The more you press the accellerator, the less vacume there is in the intake no matter weather it is forced or naturally aspirated. The less vacume present in the intake, the more "pinched" the return line to the tank becomes... causing the fp to go up. Fuel pressure regulators only work off of vacume (except for special "boost sensative" regulators)... and that is where FMU's come in. They aren't effected by vacume at all... only by boost (they work exactly the same, just opposite eachother). So when pressure is present, it respectively "pinches" the fuel line even more. That is why FMU hooks up to the return line for the fuel. It restricts fuel flow back into the tank even more under boost to up the fuel pressure above what the regulator can do.
I don't think it is possible to accidentaly hook the FMU to the send line from the tank, or if that would even effect it how it is, but that is something to look at. I beleive the send and return use different size connectors anyway to eliminate that possibility, but it's worth looking at.
I don't think it is possible to install a regulator wrong either, I am pretty sure they only install one way, but that is something else to look at.
My first guess would be that something with either the fmu or especially the regulator is screwed up. It sounds to me like the regulator for some reason is working backwards from what it should be.
To troubleshoot which one is the problem... removing the FMU from the fuel line will tell you right away which one it is. That would be my first mode of troubleshooting.
Please keep us updated as to what you find out.
Just like I said before... do these things to troubleshoot. Also, if you KNOW that there is something not right and your car isn't running right (missing O-Ring)... fix it. I don't think that would cause anything like this, but you never know. If there are known missing parts or things that are not right and you are having problems... first things first, fix what you KNOW is wrong (1st rule of troubleshooting anything) then go from there to further troubleshoot as neccessary. Do what I said above and you will have troubleshot everything.