Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)
dsulu

Fuel Pump Relay

Recommended Posts

Hi, folks,

I am looking some instruction to troubleshoot Fuel Pump Relay, I was wondering if anyone can point me in a right direction. ( I did search the forum for a while )

Also, How do you “jump” 87 and 30 fuse?

Would a defective relay throw a code?

Any help is greatly appreciated.

1998 2.5 litre, 5-speed.

Problem: still troubleshooting engine stalling (fuel cut-off?) problem when the engine warms up ~180 degree.

Code: no code displayed using Durametric

Share this post


Link to post
Share on other sites

If you suspect a relay why not just change it. Often relays are generic items and similar relays (just a switch that allows high power transmission) can be sourced from Hella or Bosch. Printed on the relay housing is a rating value and a line diagram of its function.

Jumping fuses can be dangerous stuff and can cause fires. The fuse has a function. When power consumption in that track is too high it blows to prevent overheating and damage. It's much better to check continuity of circuits with a meter before you start jumping fuses.

Take care

H

Share this post


Link to post
Share on other sites

Hi, folks,

I am looking some instruction to troubleshoot Fuel Pump Relay, I was wondering if anyone can point me in a right direction. ( I did search the forum for a while )

Also, How do you “jump” 87 and 30 fuse?

Would a defective relay throw a code?

Any help is greatly appreciated.

1998 2.5 litre, 5-speed.

Problem: still troubleshooting engine stalling (fuel cut-off?) problem when the engine warms up ~180 degree.

Code: no code displayed using Durametric

This is how the jumper works:

Pic2.jpg

But before we even go there, have you connected a fuel pressure test gauge to the test port on the injector fuel rail to test the car for both pressure and fuel delivery rate? If the fuel system is shutting down, you would see the sudden loss of pressure when this occurs. Another item to consider is the crank position sensor, which turns off the fuel pump when it fails to see the engine turning, and which also has a tendency to only do this when the engine is warm.

Share this post


Link to post
Share on other sites

Folks, thank you for the quick replies and helpful information.

Also, thank you for the clarification on “jump” 87 and 30, they are not fuse numbers but rather the connector number on a board. Is this is located right under the steering wheel?

I will also need to perform a fuel pressure test, is there any write up with photos in the forum, I did look for it for a while.

JFP, you mentioned in one of your replies that there is a Schrader valve on the fuel rail, is it on both fuel rail or just one side? (any photo avail?)

I just replace CPS this weekend. Initially hard to find, once found, the installation is straight forward. I did check the Ohm (resistance) on the old CPS and it is within the spec. therefore that is not the problem.

I have replaced and cleaned a number of things in the past 2 years, TB, idle control valve, fuel filter, fuel pump, AOS, J-tube, breather tube and I even bought Durametric tool for troubleshooting and I am still living with this problem. I am now starting to wonder if the fuel pump is defective even though I replaced it about 2 years ago and I noticed that is when this engine stalling problems started occurring a few months after that.

I also noticed during test drive, on the 3rd and 4th gear, the car feels weak like not enough fuel is getting to engine. Is there a way to test fuel pump ( voltage, resistance etc ) in addition to fuel pressure test?

As always, thank you all for your help.

Share this post


Link to post
Share on other sites

Folks, thank you for the quick replies and helpful information.

Also, thank you for the clarification on “jump” 87 and 30, they are not fuse numbers but rather the connector number on a board. Is this is located right under the steering wheel?

I will also need to perform a fuel pressure test, is there any write up with photos in the forum, I did look for it for a while.

JFP, you mentioned in one of your replies that there is a Schrader valve on the fuel rail, is it on both fuel rail or just one side? (any photo avail?)

I just replace CPS this weekend. Initially hard to find, once found, the installation is straight forward. I did check the Ohm (resistance) on the old CPS and it is within the spec. therefore that is not the problem.

I have replaced and cleaned a number of things in the past 2 years, TB, idle control valve, fuel filter, fuel pump, AOS, J-tube, breather tube and I even bought Durametric tool for troubleshooting and I am still living with this problem. I am now starting to wonder if the fuel pump is defective even though I replaced it about 2 years ago and I noticed that is when this engine stalling problems started occurring a few months after that.

I also noticed during test drive, on the 3rd and 4th gear, the car feels weak like not enough fuel is getting to engine. Is there a way to test fuel pump ( voltage, resistance etc ) in addition to fuel pressure test?

As always, thank you all for your help.

Passenger's side fuel rail (item #7):

fuel+rail1336794992.jpg

Pressures:

Engine off 3.8 +/- 0.2 bar

Engine idling 3.3 +/- 0.2 bar

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.