Zero fuel pressure at the rails

[Qwkspool]

Hey guys, I am having problem with fuel pressure. I have. 87 grand national. The car already had a hi flow fuel pump on it and a volt booster. The previous owner tapped into the fuel pump harness with a power wire and runs through the trunk and up to the front. I am not sure why or where this wire ends up. I installed a racetronix hot wire kit, 60 lbs fuel injectors, and a electric fuel pressure gauge. With the the key on, I get 0 fuel pressure. If I take off the gauge fitting at the end of the rail, and turn key on, fuel comes shooting out. But I still get nothing on the gauge. If I start it up, it will run really rough and the die. It also seems to be pulling a lot of vacuum. Anyways, I not sure why I have 0 fuel pressure. I forgot to add,I installed a TT chip for the 60 lbs injectors.

 

[Qwkspool]

I forgot to add, I also installed a accufab fpr

 

[87_we4]

Is the pump priming when you turn the key on? What brand fuel pump? How old is the fuel pump?

Posted from the TurboBuick.Com mobile app

 

[john keskes]

Fuel filter ? gas in the tank ? bad FP gauge ?

 

[Qwkspool]

There's gas in, I changed the fuel filter, and the gauge is brand new. Plus the car runs like crap and then dies so. Now there is no pressure.

 

[john keskes]

The car ran fine before you modded ?

 

[Qwkspool]

Yes

 

[john keskes]

Check the voltage to your pump. i am running an electric FP gauge also. It should be pressurizing to at least 37-43 psi when your ready to start the car and should not go lower when it starts & idles.

 

[Chuck Leeper]

<5psi at the rail will shoot fuel out....But, may not trigger a reading on the ga.
Filter in backwards?

 

[psycho6cyl]

How did fuel pump sock look? Did you replace that also? I think I would just retrace all your steps starting with the easy stuff. As stated above Check fp voltage check fp. Filter... and get a known working guage from a friend just to be 100% sure.

 

[Qwkspool]

I just got fuel pressure by running a wire from the grey test connector below the alternator to the power on the back of the alternator. I can feel it in the fuel pressure regulator when I did this. I got a steady 43 psi. The regulator sounds like it keeps clicking every couple of seconds, is this normal?

 

[john keskes]

it sounds like you have an issue with the H.W. don't know about the clicking sound, i use a -237 .

 

[Shawn N]

You will have to figure out the redneck pump power lead and either use it in the new kit or splice the wire he tapped into back together. Most homemade hot wire for fuel pumps tap into the relay and one wire goes to the alt stud for power. The second wire (most likely starts from the pass side relay bank) will run to the harness below the rear bumper and tie into the pump wiring there (pump side of the harness). The gray wire is the 12v hot on the body side of the harness for a 87. It has to 12v to turn the pump on or the hot wire relay. If you can't figure it out then post pics of where the wire starts and ends.

 

[Qwkspool]

Even if I disconnect the hot wire kit and just put it back to stock I am still having a problem. Im thinking its the relay. The relay looked really crudded up.

 

[Shawn N]

If it has black tar looking crud all over the relay bottom it's just dried up dielectric grease from the factory. If it has made it's way onto the contacts inside it will need to be cleaned or replaced.

 

[Qwkspool]

Yea there's tar all over the place. I could barely see the contacts. I tired scraping them with a small screwdriver but there is still a decent amount of tar. This is the harness the previous owner tapped I to. Not sure why. Another weird thing is if I use the grey connector to get fuel pressure, the car will stay running even if I take the keys out! The engine stops when i disconnect the test wire.

 

[Shawn N]

That test wire is a constant 12v and the other has 12v only when the key is on. That's a pretty amateur hot wire. The better ones actually remove the gray wire from the body connector and insert the hot wire in its place. If done right it increases the voltage to the pump by a volt or two. The stock GM wiring is terrible and the pump only sees 10.5v most of the time. Casper's hot wire kit is one of the best I've used.

 

[Qwkspool]

I have the racetronix hot wire kit. I just pulled it aside and reconnected the factory harness to Take the picture. But I still can't get fuel pressure unless I use the test connector.

 

[Shawn N]

Is the pink wire cut at the relay?

 

[broke]

If the car runs bad it sounds like the pump is priming. You said you install a new regulator, did you screw the adjuster down to raise the pressure. If there is no tension on the spring it will build very little pressure if any.