z or bust Posted July 22, 2008 Share Posted July 22, 2008 I have a 77 S30 all stock and my fuel pressure will seem to slowly drop after about 30 mins of running. I'll turn the car off for about 10 mins and it will hop back up to where it is supposed to be. but then will start to fall away again after a minute or so. Could the fuel pump be bad? and once it gets hot from running it starts slow down? Has anyone else experienced this problem? Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted July 25, 2008 Share Posted July 25, 2008 Hard to say, to be honest. Fuel pressure is directly linked to manifold pressure (or vacuum). Timing is very commonly higher when a car first starts and then slowly tapered out; even if the car was already warm when it fired up. You really need to see that the ratio of fuel pressure to manifold pressure stays constant. It's usually 3 bar, but the EFI manual will tell you the exact curbe pressure. Quote Link to comment Share on other sites More sharing options...
z or bust Posted July 25, 2008 Author Share Posted July 25, 2008 Figured it out. My tank was loaded full of crap. I had to drop it and clen it all out. That did the trick. Thanks Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.