 Another fuel pressure question, Diagnosis help please |
|
|
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
|
| boiledcabbage |
 Sep 4 2012, 03:17 PM
Post
#1
|
|
Member  Group: Members Posts: 50 Joined: 23-May 05 From: Ottawa, Canada Member No.: 4,131  |
Tracking a performance problem on my stock 74 1.8 FI and would appreciate any thoughts:
Sluggish in 3rd and above and wondering if fuel is the issue. starts and idles well,good compression, recent tuneup and valve adjustment although I did it myself... 32psi at idle, 29psi at 3000rpm measured at the CSV, volume only 1.0 liter perminute, no visible kinks or bundle in the tank. Any thoughts? I will be double checking the vacuum advance and timing just in case... |
   |
 
|
  |
Replies
| pilothyer |
Sep 4 2012, 09:39 PM
Post
#2
|
|
Member Group: Members Posts: 838 Joined: 21-May 08 From: N. Alabama Member No.: 9,080 Region Association: South East States |
Although your fuel pressure regulator seems to be in spec, you may want to test it several times to be sure it doesn't have a diaphragm leak....warm up the engine with the fuel pressure gauge connected.........at idle (high vacuum) the FPR should maintain about 28 psi.....pull the vacuum connection (simulating under load condition) and the pressure should rise to about 35 psi.... reconnect the vacuum to FPR and the pressure should again fall to about 28 psi............when you remove the vacuum source from the FPR plug it with your thumb because any vacuum leaks will cause problems.
|
|
|
|
| boiledcabbage |
Sep 6 2012, 05:51 PM
Post
#3
|
|
Member Group: Members Posts: 50 Joined: 23-May 05 From: Ottawa, Canada Member No.: 4,131 |
QUOTE(pilothyer @ Sep 4 2012, 07:39 PM)  Although your fuel pressure regulator seems to be in spec, you may want to test it several times to be sure it doesn't have a diaphragm leak....warm up the engine with the fuel pressure gauge connected.........at idle (high vacuum) the FPR should maintain about 28 psi.....pull the vacuum connection (simulating under load condition) and the pressure should rise to about 35 psi.... reconnect the vacuum to FPR and the pressure should again fall to about 28 psi............when you remove the vacuum source from the FPR plug it with your thumb because any vacuum leaks will cause problems. Thanks pilothyer (and others for your help) I had not thought to check the pressure with and without vacuum on the FPR -I'll see what happens..... |
|
|
|
Posts in this topic
boiledcabbage Another fuel pressure question Sep 4 2012, 03:17 PM
underthetire And check the mechanical advance as well. Sep 4 2012, 03:25 PM Dave_Darling One liter per MINUTE? That sounds like a seriousl... Sep 4 2012, 04:26 PM boiledcabbage Thanks Dave -no I really did mean 0.5l in 30 secon... Sep 4 2012, 04:30 PM SLITS Spec is 50 - 62 L/hr .... 0.83 - 1.03 L/min .... b... Sep 4 2012, 04:53 PM
boiledcabbage
Spec is 50 - 62 L/hr .... 0.83 - 1.03 L/min .... ... Sep 4 2012, 05:08 PM Dave_Darling Crap, I had the units wrong! Thanks for check... Sep 4 2012, 08:24 PM kg6dxn I once had a fuel filter with a blockage that woul... Sep 4 2012, 09:04 PM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 3rd July 2025 - 12:12 PM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.