Fuel pressue question

[NM Tom]

I bought a GN that appears to be all stock. Put a gauge on the fuel rail and I have 43# fuel pressure with vacuum line off. It does have a stock regulator and is is safe to assume it has the stock pump? Dont want to pull the tank if I dont have to. Thanks

 

[TWISTER]

Whats the question???

 

[NM Tom]

Just wanting to know if I have the stock pump still installed or not.Dont want to drop tank if someone already upgraded pump.

 

[salvageV6]

No way of knowing with this old of a vehicle without looking.

Just my .02.

You can't infer anything from the data given.

Seems a bit high in pressure to me for a stock regulator.

I'd look to upgrade to a Walbro 340 and you will know for sure that a good pump is in the car.

 

[brn agn]

Hey NM Tom, I asked this same question after I purchased our TTA. I suspected that the car had an aftermarket pump and I had seriously considered not changing the pump. The response I got from fellow board members was, "change it, you don't know what is in there". To make a long story short, I changed the pump last weekend and added a hot wire kit. To my surprise the pump that was in the tank was an AC Delco unit! I am very happy that I swapped in a pump that I can depend on. It's cheap insurance. I recommend changing yours out also.

 

[49-blues]

NM tom-you probably have the stock looking 237 regulator from the tta-the stock gn regulator is 233 which is about 28 psi.

 

[NM Tom]

Double checked regulator and it is a 233 factory unit. Does the fact that I am running that high of pressure with that regulator denote a problem? The gauge is good as I took it off my friends TTA and it read correctly there.

 

[Darklord]

You can always check your fuel pressure at wot to see where it's running. If it looks good then you may already have a good aftermarket pump. I think the general rule for fuel pressure at wot is 1psi for every lb. of boost. With 43 psi at idle you should see 60 psi at 17 lbs. boost. Guys it's been awhile so correct me on this if I'm wrong.

 

[azgn]

the pump does not control fuel pressure...the regulator does....if the pump cannot supply the required volume at a certain pressure, then your pressure will drop off (or not track)

if you have 43 lbs at idle, with the vac line off and a 233 regulator, something is amuck, or somebody squashed the regulator for the increased pressure