: Fuel pressure regulator

05-12-14, 06:46 AM
How can I tell when my fuel injection pressure regulator is going bad? 2003 cadillac deville

05-12-14, 06:50 AM
Disconnect the vacuum hose from it with the engine idling. Any sign of fuel at the nipple indicates a ruptured diaphragm - failed FPR.

Why? Having an issue?

05-12-14, 07:41 AM
Long story short, I changed my spark plugs and a friend of mine took the clamp off my fuel pressure, I guess he was trying to make room. After everything was done he couldn't remember where he took the clamp off of, I never saw him when he first disconnected it so I had no clue. I drove it around for a few weeks without the clamp and it never drove right. It wouldn't accelerate either, until the other day my car stop on me it wouldn't crank, heavy gas smell and I notice it leaking. I got it towed and she sat for 3 days. I bought the Haynes book, and I notice the clamp holds down that fuel pressure, I put it back on and she crunk right up! She now accelerates too, the next day she wouldn't crank until I kept turning the ignition and I had to keep my foot on the gas. Next day after that she crunk right up with no problem, next day after that....same problem, wouldnt crank!


Thx for the info by the way

05-12-14, 09:30 AM
You're lucky to be alive. Is the "clamp" actually the hairpin clip shown ? It's a wonder you didn't have 45 psi gasoline squirting EVERYWHERE !

05-12-14, 11:00 AM
I am surprised you didn't have a gas geyser followed by a huge fire under the hood. There is at least 40 psi of fuel pressure in that fuel rail. Can't imagine what was keeping that regulator in the rail. You need to get on your knees and thank God for looking over you. You are VERY, VERY lucky. That said, fuel pressure has nothing to do with cranking.

Red circle is the FPR & retaining clip.

Check it like this
https://encrypted-tbn2.gstatic.com/images?q=tbn:ANd9GcQHCfLIHG_zWxIhacsQKXz5QluIDLgGO MMd4EIIFf9fOCbM2QA