Fuel pressure - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
Ford Tempo Forum | Mercury Topaz Forum Forum for discussion of the Ford Tempo and Mercury Topaz.

LinkBack Thread Tools Display Modes
post #1 of 2 (permalink) Old 08-04-03, 12:46 PM
Posts: n/a
Fuel pressure

I have a 90 Topaz XR5 that has had a stumbling start since the first day I drove it (4/90). It recently has become worse, so I bought a fuel pressure guage and a vacuum gun to do some trouble shooting. First, I didn't find any vacuum leaks and the fuel pressure regulator test with the engine running works fine (~40psi with vacuum ~50psi without).

Now the problem. After the car sits overnight, the fuel pressure drops significantly down to 0psi - 10psi. The first key on, the pump engages and the pressure rises to about 20psi. I then key off and key on several more times before the pressure goes up to about 50psi and tops out. Sometimes, the fuel pressure actually drops back to 0psi. If I have good pressure and I start the car, it still stumbles until I give it just a little "gas". It then idles fine. I'm thinking that I may have pressure eventually at the fuel rail, but I'm thinking some of that is air and not fuel. Does the drop in pressure mean a bad regulator or fuel pump check valve? Any easy way to tell? If anyone has any suggestions, I sure would appreciate them.

Oh yes, there are no fuel leaks (on the floor, etc) that I can find.


Sponsored Links
post #2 of 2 (permalink) Old 08-08-03, 12:50 PM
***** Idiot....
LunaticSVT's Avatar
Join Date: Feb 2001
Location: The Sticks of Central TX
Posts: 10,560
Re: Fuel pressure

I know on that model there was a TSB for the Fuel pump.

TSB #: 921211
TSB: Fuel Pump/Sender - Obsolete Parts Purge
LunaticSVT is offline  
Sponsored Links

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Ford Cars and PAG Vehicles > Ford Tempo Forum | Mercury Topaz Forum

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fuel pump pressure b-juggles General Tech 4 08-12-02 04:48 PM
Ford Product-Led Transformation: 2003 RPO83 Trans | Driveline 0 07-22-02 06:48 AM
XF I6 EFI fuel psi pressure vs. EB-EL EFI V8 fuel psi pressure MadMax Inline 6 Tech 15 06-13-02 12:46 AM
Ford's goal of boosting SUV fuel economy proves elusive Stacy94PGT Ford Worldwide News 0 04-19-02 07:47 AM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome