 Dwell Angle, Timing, and CHT sensor questions, Timing way off (well above 27 Deg) but runs...??? |
|
|
|
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. |
|
|
| NJ914 |
 Nov 13 2023, 10:57 AM
Post
#1
|
|
Newbie  Group: Members Posts: 37 Joined: 2-November 15 From: Bernardsville, NJ Member No.: 19,324 Region Association: North East States  |
Looking for inputs from those who know...
Situation: Engine runs but timing is way off. 27 degrees is at 1800rpm[b]. 3500rpm is in the mid to upper 30's. When attempting to adjust the distributor to spec, engine dies. Only runs at higher timing angle. Not sure what the cause is. 1: Distributor gap is currently at 0.018" and dwell is 50-51 degrees through speed range. Per the Haynes book, 1 degree of dwell can change the timing by 3 degrees. Spec is 44 to 50 degrees. Is this correct? If I open the gap larger to bring the dwell down to 44 degrees, will this help bring the timing closer to spec? 2: Measured the CHT sensor cold and it was 3100 ohms. I believe it is supposed to be more in the 2000 - 2500 ohm range...? What is the correct range for the CHT sensor cold? It is supposed to drop below 100 ohms when up to temp. Is this correct? Could the higher than spec resistance of the CHT sensor be contributing to the timing issue? |
   |
 
|
  |
Replies
| GregAmy |
Dec 18 2023, 04:12 PM
Post
#2
|
|
Advanced Member Group: Members Posts: 2,490 Joined: 22-February 13 From: Middletown CT Member No.: 15,565 Region Association: North East States 
|
(IMG:style_emoticons/default/agree.gif)
Where I was going with this...you have not yet verified that the timing mark on the fan is in the actual correct position or is the correct one. You could be looking at the wrong mark, or (sorry, I can't resist) the fan hub has spun on the crankshaft. On my 2L - what engine is yours? - I have a notch on the flyhweel at #1 TDC that's visible from an access hole at the top of the transaxle; you might have to push the sheet metal back to see it. Compare that mark to the fan marks, see if they agree. http://www.914world.com/bbs2/index.php?showtopic=339759 http://www.914world.com/bbs2/index.php?showtopic=342133 http://www.914world.com/bbs2/uploads/post-...-1565184944.jpg And rechecking proper valve clearance is easy enough. http://www.914world.com/bbs2/index.php?showtopic=28758 I can't see how the cam was mis-dialed-in and yet "[e]ngine ran without issue until a few years ago when it was removed to correct oil leaks." So I think it's something simplier. - GA |
|
|
|
Posts in this topic
NJ914 Dwell Angle, Timing, and CHT sensor questions Nov 13 2023, 10:57 AM
StarBear 1. Dwell Looks right on. Sure you have light on th... Nov 13 2023, 01:24 PM
NJ914
1. Dwell Looks right on. Sure you have light on t... Nov 13 2023, 01:58 PM 914sgofast2 I suggest taking the dizzy out of the engine and d... Nov 13 2023, 01:43 PM NJ914
I suggest taking the dizzy out of the engine and ... Nov 13 2023, 02:00 PM StarBear Here is one of many threads on the CHT temp curve:... Nov 13 2023, 02:46 PM NJ914 With some help from @Starbear this past weekend,... Dec 5 2023, 12:58 PM Geezer914 Sounds like the cam timing is off. Is this an ori... Dec 5 2023, 02:42 PM NJ914
Sounds like the cam timing is off. Is this an or... Dec 13 2023, 01:22 PM 914_teener It is not necessary to remove the engine to replac... Dec 13 2023, 03:07 PM VaccaRabite I suspect you have a configuration error.
What ar... Dec 14 2023, 11:21 AM NJ914
I suspect you have a configuration error.
What a... Dec 18 2023, 02:43 PM Dave_Darling See if you can compare the marks on the fan to the... Dec 14 2023, 07:41 PM GregAmy
See if you can compare the marks on the fan to th... Dec 14 2023, 09:24 PM Superhawk996
See if you can compare the marks on the fan to t... Dec 14 2023, 09:29 PM NJ914
See if you can compare the marks on the fan to th... Dec 18 2023, 02:44 PM VaccaRabite
See if you can compare the marks on the fan to t... Dec 18 2023, 03:59 PM emerygt350 Yeah, verify tdc first but I don't think you a... Dec 14 2023, 08:04 PM NJ914
:agree:
Where I was going with this...you have ... Dec 20 2023, 01:44 PM Dave_Darling
1: The distributor rotor is pointing toward the #... Dec 20 2023, 03:00 PM NJ914
1: The distributor rotor is pointing toward the ... Jan 2 2024, 03:22 PM NJ914
[quote name='Dave_Darling' post='3119075' date='D... Jan 8 2024, 11:49 AM emerygt350 TPS doesn't even need to be hooked up and the ... Jan 8 2024, 12:02 PM NJ914
TPS doesn't even need to be hooked up and the... Jan 9 2024, 02:21 PM GregAmy Yuuuuup.
And you're using an adjustable timin... Dec 20 2023, 02:44 PM StarBear Aarghhh. Looking for a great ending! Jan 8 2024, 04:48 PM |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
|
Lo-Fi Version | Time is now: 9th May 2025 - 02:37 PM |
Invision Power Board
v9.1.4 © 2025 IPS, Inc.