 Popping on decel, fuel pressure regulator? |
|
|
|
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. |
|
|
| PDXMike |
 Sep 26 2015, 06:40 PM
Post
#1
|
|
Slowly Learning  Group: Members Posts: 111 Joined: 20-December 10 From: Portland, OR Member No.: 12,501 Region Association: Pacific Northwest  |
Hey all,
My 75 1.8 L-jet has always popped on decel. I've looked for exhaust leaks, including dropping and reinstalling the entire exhaust and getting it smoke tested. My decel valve is working correctly. This thing makes a LOT of noise, even when just letting the engine spin down with the clutch in. It sounds like some crazy-tuned dirt track stock car or something. This is fun for the first 5 minutes or so, then anybody within 100 yards of me wants to run me off the road. While testing my decel valve, I noticed that the same vacuum line that controls the decel valve also runs to the fuel pressure regulator. Is it supposed to cut the fuel supply off when vacuum pressure goes up? Could this have anything to do with my popping? If the injectors are still firing I'd be pumping gas right through into the exhaust, right? I have a Monza muffler, which probably isn't helping. Is this a crazy theory? What else can I try? Thanks, Mike |
   |
 
|
  |
Replies
| catsltd |
Sep 28 2015, 07:46 AM
Post
#2
|
|
Member Group: Members Posts: 181 Joined: 7-June 15 From: Calgary Alberta Member No.: 18,814 Region Association: None |
My 74 1.8L Monza exhaust popped a lot on decel,(no decel valve.)
I had a hole where it joins the muffler,fixing the whole did not stop the popping. My timing was the problem. Even though the mufflers leak is back,there is no more popping. My timing is set to 7.5 BTDC from the red mark on my pulley. I downloaded the PDF and printed the template and went with that. Not sure what a 75 is tuned to,just trying to help. Grant. |
|
|
|
| PDXMike |
Sep 28 2015, 03:32 PM
Post
#3
|
|
Slowly Learning Group: Members Posts: 111 Joined: 20-December 10 From: Portland, OR Member No.: 12,501 Region Association: Pacific Northwest |
Grant,
7.5 BTDC sounds familiar. That's pretty easy to check so I'll move that to the top of my list. Mike QUOTE(catsltd @ Sep 28 2015, 06:46 AM)  My 74 1.8L Monza exhaust popped a lot on decel,(no decel valve.) I had a hole where it joins the muffler,fixing the whole did not stop the popping. My timing was the problem. Even though the mufflers leak is back,there is no more popping. My timing is set to 7.5 BTDC from the red mark on my pulley. I downloaded the PDF and printed the template and went with that. Not sure what a 75 is tuned to,just trying to help. Grant. |
|
|
|
Posts in this topic
PDXMike Popping on decel, fuel pressure regulator? Sep 26 2015, 06:40 PM
The Cabinetmaker FP regulator only has two nipples. One is fuel in,... Sep 26 2015, 08:06 PM Grump My 75 1.8 also has this vacuum hose connection. It... Sep 27 2015, 01:21 PM
Mikey914 If not A&P isn't too far away. Sep 28 2015, 04:27 PM
porschetub [quote name='PDXMike' date='Sep 27 201... Sep 29 2015, 12:48 AM |
2 User(s) are reading this topic (2 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 6th January 2025 - 05:44 PM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.