 Runs rough - spark plug doctors? |
|
|
|
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. |
|
|
| torakki |
 Apr 17 2021, 07:31 PM
Post
#1
|
|
Newbie  Group: Members Posts: 43 Joined: 5-October 18 From: Nor Cal Member No.: 22,545 Region Association: Northern California  |
On my '74 2.0, I can't get it to run right. It's gone through a restoration and put aside for 2 years. Now, back on it and it's almost done but[b] number 1 and 4 spark plugs are clean/wet and 2 and 3 are black, (after 10 seconds of running). What I've done so far: Rebuilt MPS, gapped points, static timing, set fuel pressure at around 27 lbs. Compession between 90 and 110. Plugs are sparking. All injectors spray (not sure of pattern). I believe plugs were new 2 years ago. They look new. It runs really rough, white smoke out exhaust and some mild popping. I though, maybe injector triggers but all are working from my, spray in the cup, test. Dizzy backwards? Any ideas to what's going on??
Thanks for any suggestions.  |
   |
 
|
  |
Replies
| torakki |
Apr 21 2021, 05:21 PM
Post
#2
|
|
Newbie Group: Members Posts: 43 Joined: 5-October 18 From: Nor Cal Member No.: 22,545 Region Association: Northern California |
Another Update:
I put in new plugs and still runs rough but "all" plugs black with carbon now. I then, leaned out the fuel pressure regulator all the way, so the adjusting screw is almost falling out. The car runs much better but plugs still black. I set the timing at between 2500 and 3000, on the red line. I was doing it alone so, holding the timing light with crossed arms, holding the throttle open, setting the light down, move dizzy, picking up light so it's "close". I checked the cold start injector for leaking. Bone dry. Did I forget anything? I think it will run perfect if I could just get it leaned out more. Maybe, bad fuel pressure regulator? Wrong fuel pump? Anyway, that's were I'm at. Any thoughts? Thanks for reading.... |
|
|
|
| JamesM |
Apr 22 2021, 02:19 PM
Post
#3
|
|
Senior Member Group: Members Posts: 1,900 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
QUOTE(torakki @ Apr 21 2021, 03:21 PM)  Another Update: I put in new plugs and still runs rough but "all" plugs black with carbon now. I then, leaned out the fuel pressure regulator all the way, so the adjusting screw is almost falling out. The car runs much better but plugs still black. I set the timing at between 2500 and 3000, on the red line. I was doing it alone so, holding the timing light with crossed arms, holding the throttle open, setting the light down, move dizzy, picking up light so it's "close". I checked the cold start injector for leaking. Bone dry. Did I forget anything? I think it will run perfect if I could just get it leaned out more. Maybe, bad fuel pressure regulator? Wrong fuel pump? Anyway, that's were I'm at. Any thoughts? Thanks for reading.... Rather than guess, get a gauge and check your fuel pressure. My bet is that you are leaning it out with the fuel pressure to compensate for another issue and as i said before, as the MPS was opened up that is highly susspect. only two things I can think of that will cause the system to run rich to the point of stalling and that is an issue with the MPS or infinate resistance(broken wire) to the head temp sensor. A failed fule pressure regulator is usually going to cause you to have low pressure, not high. |
|
|
|
Posts in this topic
torakki Runs rough - spark plug doctors? Apr 17 2021, 07:31 PM
bbrock You say you set static timing but not dynamic timi... Apr 17 2021, 08:37 PM VaccaRabite You need to do all the basics. (In this order)
Che... Apr 17 2021, 10:03 PM JamesM
Rebuilt MPS
How did you recalibrate your MPS af... Apr 18 2021, 02:02 AM JamesM I have to ask, does the picture match the position... Apr 18 2021, 02:11 AM Tom_T
On my '74 2.0, I can't get it to run righ... Apr 18 2021, 11:55 AM TheCabinetmaker Cylinders 1&3 injectors open together.
Cylinde... Apr 18 2021, 02:04 PM torakki OK, where to start. Lots of good info coming in. ... Apr 18 2021, 03:15 PM 914sgofast2 Check the trigger points and wiring to them in the... Apr 19 2021, 01:52 PM torakki Update: Today, I started doing some of the things... Apr 20 2021, 03:32 PM
|
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 19th May 2024 - 04:50 PM |
Invision Power Board
v9.1.4 © 2024 IPS, Inc.