Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> No spark?, not sure what to check
biosurfer1
post Apr 27 2009, 10:49 PM
Post #1


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
I tried to get my new engine going for a couple hours tonight and it just cranks, no fire.

Got fuel to the carbs, but no spark at the plugs (IMG:style_emoticons/default/sad.gif)

Checked the coil and I get 12V off each side to ground, is this correct?

What is next in the diagnosis...what else can I check?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
yeahmag
post Apr 27 2009, 11:09 PM
Post #2


Advanced Member
****

Group: Members
Posts: 2,421
Joined: 18-April 05
From: Pasadena, CA
Member No.: 3,946
Region Association: Southern California
That isn't right... Are you running points?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dr. Roger
post Apr 27 2009, 11:50 PM
Post #3


A bat out of hell.
****

Group: Members
Posts: 3,944
Joined: 31-January 05
From: Hercules, California
Member No.: 3,533
Region Association: Northern California
pos + on the coil should read about 12V. the neg - on the coil should go to the points and to a condensor.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Apr 28 2009, 12:17 AM
Post #4


914 Idiot
**********

Group: Members
Posts: 14,984
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California
Unplug the black/purple (thinner) wire from the coil. (It should have been on the - terminal, BTW.) Now make sure that the green wire from the points/condensor gets shorted to ground and then disconnected as the distributor rotor turns.

How's the ground braid inside the distributor? The points ground through that.

--DD
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Katmanken
post Apr 28 2009, 07:49 AM
Post #5


You haven't seen me if anybody asks...
****

Group: Members
Posts: 4,738
Joined: 14-June 03
From: USA
Member No.: 819
Region Association: Upper MidWest
If you have the stock system, remove the distributor cap.

Connect one end of a test lamp on the negative (point side) of the coil and the other to ground. Crank the engine and if you get a pulsing light, the points and coil are working.

If the light stays ON or stays OFF during cranking, then the problem is not the coil and you need to look elsewhere- such as the points and condenser.

Put the test lamp across the positive and the negative terminals of the coil. Have somebody crank the engine over, If it pulses, then this means there is 12 v to the + and - terminals, and the points and condenser are working.

Look at the points, if they spark when opening and closing, you probably have a bad condenser.

Put the cap back on. If you still have no spark, then either the coil is bad or one or more of the coil wire and/or spark plug wires are shot.

Hope this helps.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
computers4kids
post Apr 28 2009, 08:03 AM
Post #6


Love these little cars!
****

Group: Members
Posts: 2,443
Joined: 11-June 05
From: Port Townsend, WA
Member No.: 4,253
Region Association: None
Brett,
besides the comments about wiring...have some one crank the engine and go back and verify the rotor is really turning inside the dizzy and check if the points are opening and closing. While your at it, pull the coil wire and see if your getting spark out of the coil. I know the above is probably a no brainer and you've probably already done this, but a good place to start.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post Apr 28 2009, 08:59 AM
Post #7


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
Thanks for the replies...I'll start the process of going through everything tonight, ran out of time last night.

We pulled the cap and the rotor and points looked fine, but I'll double check for spark. We switched out the coil for one I had laying around and still no go.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post Apr 28 2009, 08:38 PM
Post #8


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
I'm still waiting for some help to arrive to help with cranking, but in the meantime, I'm still a little confused why I'm getting 12V off both the + AND - side of the coil when the key is in the ON position, shouldn't I only get 12V off the + side?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
ArtechnikA
post Apr 28 2009, 08:41 PM
Post #9


rich herzog
*****

Group: Members
Posts: 7,390
Joined: 4-April 03
From: Salted Roads, PA
Member No.: 513
Region Association: None
QUOTE(biosurfer1 @ Apr 28 2009, 10:38 PM) *

...shouldn't I only get 12V off the + side?

The short version is you'll only see ground on the - side when the points are closed.

If you turn the engine by hand and you -never- see ground at the 12V side, find out why your points are not closing. You get spark -only- when the points open.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post Apr 29 2009, 10:28 PM
Post #10


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
Still coming up with nothing...

I don't have a test lamp, so I just used a multimeter expecting to see a voltage drop. When cranking, I get the same thing off both sides of the coil...the voltage drops from ~12V to ~10.5V and holds there. I pulled the coil wire off the distributor and couldn't see a spark while cranking, but I'm not sure if I should "see" it for sure.

Points are opening and closing and the ground braid looks fine..both the distributor and coil look new, but who knows...

Any ideas?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Apr 30 2009, 08:49 AM
Post #11


914 Idiot
**********

Group: Members
Posts: 14,984
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California
Unplug the points wire at the distributor. Now check to see if it goes to ground and then gets disconnected when you rotate the engine. It's easier if you rotate it slowly, possibly with the turn-one-wheel-in-5th-gear trick.

Does it get grounded and then disconnected? If not, then the points or the points plate or the ground braid are the problem.

--DD
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post Apr 30 2009, 08:54 AM
Post #12


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
Thanks Dave...I'll try that tonight
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post May 2 2009, 10:01 PM
Post #13


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
well I got it figured out...thanks to Justin looking closer, he saw there was come corrosion on the points. A little sandpaper and it fired right up!

First time hearing the the engine and my car running in 10 months (IMG:style_emoticons/default/smilie_pokal.gif)

I'll update more later:)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
computers4kids
post May 3 2009, 08:53 AM
Post #14


Love these little cars!
****

Group: Members
Posts: 2,443
Joined: 11-June 05
From: Port Townsend, WA
Member No.: 4,253
Region Association: None
QUOTE(biosurfer1 @ May 2 2009, 09:01 PM) *

well I got it figured out...thanks to Justin looking closer, he saw there was come corrosion on the points. A little sandpaper and it fired right up!

First time hearing the the engine and my car running in 10 months (IMG:style_emoticons/default/smilie_pokal.gif)

I'll update more later:)

That's fantastic...updates please, with pictures. (IMG:style_emoticons/default/popcorn[1].gif)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
r_towle
post May 3 2009, 10:39 AM
Post #15


Custom Member
***************

Group: Members
Posts: 24,574
Joined: 9-January 03
From: Taxachusetts
Member No.: 124
Region Association: North East States
Hi,
Replace the points. They are plated and once they have pitting, they are pretty much done and will never stay clean.

New points cost $4.00
Go get some....get two sets so you always have a new set on hand.

Rich
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
biosurfer1
post May 3 2009, 07:27 PM
Post #16


Teener fo Life!
****

Group: Members
Posts: 3,020
Joined: 3-August 03
From: Roseville, CA
Member No.: 977
Region Association: Northern California
Already one step ahead of you Rich... already ordered new cap, rotor, points, etc.

Just excited I have a running car until they show up:)
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 12th May 2024 - 09:08 PM
Invision Power Board v9.1.4 © 2024  IPS, Inc.
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 ...