And Now The Rest Of The Story (Fuel Pressure Issues Solved!)

Post by **rgrady** » 13 Jan 2009, 07:39

In recent posts (have not figured out how to link to previous post yet) I was working on a low power, no acceleration issue. Thought I had it solved when I replaced the fuel pressure regulator. When I replaced the regulator I was pushing about 39 PSI. I figured the lower pressure was just the cheap pressure gauge I bought. But the plot thickened!!!
On the way home from work yesterday (60 mile drive)the car was running great. Boosting good plenty of power. A few miles from the house I stopped and filled the tank up. I was down to a gallon or 2. When I left the station it started giving the same low power, no acceleration problem. Was real bad this time. Car was surging and barely accelerating. I discovered I can shout very many foul words during a 4 mile drive.
Got home and started trouble shooting. Only had 20 PSI max fuel pressure and would drop to zero within 2 seconds of turning the key on. Car would start, idle and rev great sitting in park. Crappity crap crap....WTF is going on? Did my precious 60.00 auto zone special fuel regulator crap out?
I decided to take off work today, go to Volvo of Richardson ( 80 mile drive) and buy fuel pump assembly, fuel pressure regulator and any other widget I could think of while I was there. Sitting here this morning I decided to go ahead and pull the pump out while waiting for them to open. I pulled up the "how to remove fule pump" thread in the repair data base. Read through it and one of the last entries talked about the hose in the pump assembly shrinking and barely making contact with the discharge tube. HMMMMMM....could it be that simple. I pulled the pump and sure enough the hose was barely making contact. SWEEEEEEEET. But the hose had not shrunk as stated in the repair thread. The pump had slid down in the assembly pulling the hose off of the tube. It is normally only on about 3/8 to 1/2 inch on the tube. I loosened the clamp, slip the pump back up and retightened the clamp. Reassembled everything and took a a pressure reading. WA-LA...had 44 PSI on the gauge and holding steady. Took a test drive and it was a rocket sled once again. YEEEEEEEHAAAAAW as we say in TEXAS.
I ran the events of the last couple of weeks through my mind and everytime I had the more serious problems I had a full tank of gas. Best I can figure is with a full tank the sidewalls of the plastic tank would flex a little changing any up pressure on the bottom of the pump in turn not having as much up pressure on the hose letting fuel spew around the loose connection.
So if your having intermittant fuel pressure problems....check the hose in the pump assembly first. At least we know where to buy a less expensive fuel pressure regulator now.
Once again thanks for everyones input. You guys are great.

Post by **MadeInJapan** » 13 Jan 2009, 16:59

Great post- unfortunately, I don't think Auto Zone will take that regulator back.

Like I did before, if you don't mine, I'm going to add to the title of your post so others will have a clue what it might be about before clicking to read it.
-MIJ

Post by **confused_al** » 13 Jan 2009, 19:25

...The pump had slid down in the assembly pulling the hose off of the tube...

Did you check the plastic housing of the pump? That plastic housing which is suppose to support the pump and alone with the spring holds the pump in place (not by the hose and the clamp). Its hard to imagine the pump could just slide down with housing still in place.

Edit: At the bottom of the housing, there is a rubber base/spacer, which helps to hold the pump. If that one became loose or fells off, it would cause the pump slid down.

Post by **rgrady** » 14 Jan 2009, 17:42

confused_al wrote:

Edit: At the bottom of the housing, there is a rubber base/spacer, which helps to hold the pump. If that one became loose or fells off, it would cause the pump slid down.

That is a good point. It did look like some of the cushion on bottom was hanging out of the bottom hole. The housing was in good shape. I will pull the pump this week end and take a better look at that. Was in a hurry the other morning to get back to work so put it together as quick as I could. Pulling the pump was a lot easier than I anticipated.
Thanks MIJ for editing the title...again (ya didnt know you took me to raise did you?)

Car is running great now.
Tha main lesson I learned is...When Ozark Lee says to check the fuel pressure get off your butt and check the fuel pressure.

Thanks Lee and MIJ