How to tell between bad regulator or an INTANK problem??

[UnderPressureGT]

I had a problem with my car a few days ago.. it was only making no more then 30 pounds of pressure.. I couldnt adjust it higher, and when i turn the car off, it loses ptressure right away... I pulled the tank and noticed that the clamp was loose on my high pressure hose for the pump to pickup.. i tighened that up and put it back on... The pressure went to where it was supposed to...

Today i took it to the dyno and they told me that my regulator is actin weird when trying to adjust it... but they set my fp to 40 and ran it.... it pulled a great run at 350 hp and 375 tq..... on my way home, i didnt make it 10 miles before my car acting up on me... it was very sluggish at 4K as if it didnt wanna go nowhere..... i went home to check my fuel pressure and now it wont go no higher then 25 and IMMEDIATELY drops after i turn the car off.... we're talkin a split second here!..... what do you guys think it is?? regulator? or an intank problem.... the pump is a brand new walbro 255 pump and the regulator is a holley that is about a month old....

 

[BlackFox5.0]

I explained how to do this in your other thread. Sound like you popped the line again. If you loose pressure right away after the engine is shut down, there is obviously a leak somewhere. Since your not smelling gasoline (I assume), then it's most likely in the tank again, since it can't leak into the injectors, at least I don't think.

Here is a copy/paste that i posted in your other thread.

Start the engine, and pinch your fuel return line. It would be the smaller of the 2 hoses coming off the fuel rail. When you pinch the return line, your fuel pressure should go up. If it does not, then there is a leak in the system.

 

[87'GTstang]

I explained how to do this in your other thread. Sound like you popped the line again. If you loose pressure right away after the engine is shut down, there is obviously a leak somewhere. Since your not smelling gasoline (I assume), then it's most likely in the tank again, since it can't leak into the injectors, at least I don't think.

Here is a copy/paste that i posted in your other thread.

Start the engine, and pinch your fuel return line. It would be the smaller of the 2 hoses coming off the fuel rail. When you pinch the return line, your fuel pressure should go up. If it does not, then there is a leak in the system.

Yep, I agree. If it is a loss in pressure in an airtight system, then has to be a leak somewhere. Check all lines and make sure everything is tight from regualtor back if that is where your low pressure is from!

 

[UnderPressureGT]

I put a Kirban regulator on and that didnt fix the problem.. it wont go higher then 35.... sooo it has to be something in the tank then?>?

 

[IndyBlk5.0]

well durr

 

[UnderPressureGT]

well durr

well eat a big one!

 

[IndyBlk5.0]