Spark Plug Diagnostics for a Subaru six conversion |
|
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. |
|
Spark Plug Diagnostics for a Subaru six conversion |
nsyr |
Mar 27 2016, 03:54 PM
Post
#1
|
Because I Can Group: Members Posts: 314 Joined: 16-May 04 From: Tampa, FL Member No.: 2,073 |
I pulled the plugs on my eg33 conversion and cannot for the life of me decipher what is wrong. As you can see the 3 plugs on the left look fine. These were from one side of the engine. The 2 from the other side look to be carbon fouled with whitish tips? I was thinking weak ignition coils so I switched them around but nothing changed. I then swapped the o2 sensors with no change. Could oil cause dry carbon build up? The oil on the threads of the bad two plugs is from external leakage.
I did put new plugs in and only after 5 miles the plugs from the same two cylinders already had carbon build up while the other plugs are clean. The engine does have hesitation and surging but still feels pretty strong. I am thinking valve guide seals but would like another opinion. Attached thumbnail(s) |
r_towle |
Mar 27 2016, 04:12 PM
Post
#2
|
Custom Member Group: Members Posts: 24,591 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
You may need to tap into the ECU to see if it locked into limp mode.
If you cannot, remove both battery cables and zip tie them together for an hour, this will drain the memory of the ECU and take it out of that mode....then try again. |
Chris H. |
Mar 28 2016, 06:43 AM
Post
#3
|
Senior Member Group: Members Posts: 4,032 Joined: 2-January 03 From: Chicago 'burbs Member No.: 73 Region Association: Upper MidWest |
You may need to tap into the ECU to see if it locked into limp mode. If you cannot, remove both battery cables and zip tie them together for an hour, this will drain the memory of the ECU and take it out of that mode....then try again. I don't think these ECUs have limp mode. The OBD2's might but definitely not OBD1. The transmission controller does. Andrew, what you are describing sounds a lot like what I had....any backfiring/popping? Maybe you want to check your crank and cam sensors. If any of those are bad your timing will be totally jacked up. Just use a multimeter and measure the ohms...should have 2400 minimum when you touch the terminals with the + and - probes. Could also be something as easy as frayed or cut wires or a bad ground. |
Lo-Fi Version | Time is now: 11th June 2024 - 03:42 AM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |