friends car with 90 psi of fuel pressure

[the wrath]

i have a friend that has a 87 regal with a gn motor in it fuel pump is unknown but line off is 90 psi line on is 90 psi i tried adjusting the fuel pressure it stayed the same there is no hot wire kit on the pump and it u just turn the key to the on position without starting the car u get 80 psi what could be wrong

 

[blueta]

could be a kink or clog in the return line. I'm not sure how to check the regulator but I'm sure if you do a search it'll come up.

 

[the wrath]

when they swaped the motor in they didnt use they fuel lines from the donor car they used the original 307 lines he said

 

[blueta]

hrmm...maybe the return line is too small. If you could disconnect it and put on a hose of some sort and run it into a bucket and do a fp test that might narrow it down.

 

[y-hate]

I had the same problem, check the fuel line it is bent or has a kink in the line...check both very carefully

 

[Geoff87]

You might have a bad fuel pressure gauge! Hook up another known good gauge before trying anything else. BTDT.

 

[DavzGN]

when they swaped the motor in they didnt use they fuel lines from the donor car they used the original 307 lines he said

Since the 307 is a carbed motor it won't have a return line which probably explains the 90PSI fuel pressure. Also any flexible line in the feed line is probably not rated for Fuel Injection pressure levels. This car sounds like it is a fire bome waiting for a fuel line rupture to start it.

David

 

[the wrath]

the gauge is a good one i checked it on my gn. and yes it was a 307 carbed motor in it at first what do i do to correct the fuel return line problem how do i add on a return line

 

[TurboDave]

the gauge is a good one i checked it on my gn. and yes it was a 307 carbed motor in it at first what do i do to correct the fuel return line problem how do i add on a return line

DavesGN hit the nail on the head. The donor car wont have a return line, being a carbed 307. Your ONLY safe alternative is to get lines from a Turbo Buick.
He's got a rolling fire bomb there now.

 

[blueta]

Well if the 307 didn't have a return line what would the regulator be hooked up to? It would just spew out gas! I don't think they left it open or they woudln't have that kind of problem cause the pressure would be ok and there would be gas spilling everywhere. We need some more info!

 

[litdog83z]

many carbed cars had return lines... a lot of mechanical fuel pumps i see have 3 lines on it, one feed, one return, and one to the carb.

i'd definately try unhooking the return line and running a hose into a gas can and seeing if the pressure reads right after that... if it does your problem is in the return line like they are saying.

 

[blueta]

^^^ You know, now that you mention it I think my 83 camaro had a return line, and it was carbed.

 

[Ormand]

A lot of carbed cars had the vent line, like the turbo cars. The vent line carried vapor from the tank to the vapor canister. But as well as I can read the Buick parts manual, the return line was only used on the turbo engines. The vent line may not be big enough for a return line, and in this case, it seems like whatever is used is blocked off.