Fuel pressure problem

[kenhaw]

Ok guys, help is needed.

I have a 69 camaro with a chevy 385 Fastburn engine with the hot cam kit.
A couple of months ago I had my engine stall on me and just before that I noticed my fuelpressure was droping sometimes. I have a holley mechanical fuelpump and stainless steel lines. I have since upgraded everything with a RobbMc sending unit in the tank, 8 AN lines all the way to the RobbMc pressure regulator getting feed from a Carter mechanical fuelpump, 2 new RobbMc filters, 100 and 40 micron. All lines are new 8 and 6 AN. My pump should be able to provide 7 - 8.5 psi but I am not seing that much. I have a pressure gauge inside the car and also in the engine compartment. I am seing maybe 6 psi and sometimes 4. What is going on. I have had the car for 3 or 4 years and never had this problem before. Before the pressure would be around 8 all the time. Is this a cam lobe problem? Have read that it is important to use the right fuel pump pushrod and called a dealer who told me to use the standard non bronze tipped type. My engine has about 20.000 miles on it. When I changed the fuelpump I noticed that the pump pushrod was the normal one so I just installed that again. I have no return fuellnes since RobbMc told me that it isnt needed. I live in the south of france and it gets hot here but have never had this problem before so I dont think vapour lock is the problem either. If I change my pump to an electric which one should I get? My car is blown and carburated and if possible I would prefer not to run a return line.

Please help.

Thx

Kenneth

[Adam68]

Hi Kenneth,
I had a similar issue with my fuel system with a completely different set up. it turned out to be fuel heat and then vapour lock then the pump destroyed itself because it was tring to run on air. I ended up putting a new A1000 areomotive fuel pump and a fuel pump controler new fuel filters and aviation heat sleve over my braided lines where they were near the extractors and rear mufflers and have not had an issue since. I know you have a different system with no return line but i would say it is fuel heat. Other thing to check out is the pick up in the tank.
regards
Adam

[kenhaw]

As I wrote everything is new, pickup, filters, pump, regulator, hoses and fittings.
Didnt have any problems with the old system until recently. I drive my car every day all year around and it gets hot down here in the summer and never any problems with vapour lock. So I dont believe that is the problem now either.


Kenneth