fuel pressure going from 40psi down to 20psi

Got my car running today. Now some times it runs perfect, then a second later it will not do 5mph. The fuel pressure goes from 40 down to 20psi. I have a complete competition aeromotive fuel system. I was thinking clogged fuel filters or bad regulator. What do you think? Air/fuel gauge still peged at full rich position. please help racing on the 30th!:bonk:

It could be either of the things you described. Do you have the removable element fuel filter? If you do, remove the element and take it on a test drive.

Try disconnecting the vacuum line from the regulator and test driving the car. Watch the fuel prssure and see what happens.

Your pump can also be the problem. It is not uncommon for the Aeromotive pumps to go bad rather quickly.

The last thing could be a sticking/leaking fuel injector. Does it run rough when the fuel pressure drops? If it does. Shut the car off right away and pull the plugs, see if you have a wet plug.
Hope this helps.
Doug

It runs good untill it warms up. I pulled the vacume off of the regulator no change. Removed all the plugs, and none were wet but they all had very heavy black deposits on them. They are only like two weeks old. Cleaned them up and the pressure went back up and seemed to run better. Haven't tried pulling the filter elements yet. I don't have a fuel cut off valve so it would drain the tank. Bought a scan tool today going to try pulling some codes .

I think its the pump now. It seems to sound different. Still need to pull the line off, drain the tank, and look at the pump and filters. It will maimtain 40psi @ idle but when you drive the press goes down to 30-20. I heard a bubble sound in the regulator. I'll keep you guys posted so we can all learn from this. Thanks

Car runs good now. The filters had stuff in them so I cleaned the 100 micron and replaced the 10 micron. The other things that were wrong are the fuel level was to low. You must run atleast half a tank with the Aeromotive fuel system! My alternator was bad too. Thanks for your help!

Great! Glad to see you got it worked out!