Home 
Home Search search Menu menu Not logged in - Login | Register

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
Electrical  Rate Topic 
AuthorPost
 Posted: 03-22-2018 06:36 pm
  PM Quote Reply
1st Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
Hello JH community,
I have owned my JH (15190) since August 2015 and have been a member of the club about that long. I have never posted anything here but have researched and found answers to many questions over the last 2 1/2 years so thank you all for your help. This is my first British car and it has not (at least for me) been like starting in the shallow end of the pool.

The car had a number of electrical (among other) issues when I got it and they have slowly been gone through to the point where all the major electrical components have either been rebuilt or replaced. Only problem is, it don't run! It has in the past but hasn't since last Nov.

The tach has never worked and last fall I finally got the time to try and install the Spidya RVI to RVC conversion board purchased a year earlier. Very long story short, after speaking with Chris from Spidya many times via email and still not being able to get the thing working he suggested mailing it to him in the UK. I did, he tested it and the movement worked fine. Great, right? Wrong. I tried installing it once again and there was some movement at idle but once the accelerator was applied and as soon as the needle reached 10G it would drop back to zero. Frustrated, perplexed etc. I reached out to Chris again (who at this point is starting to feel the same way) and he suggested that maybe the coil wasn't producing enough current to operate the gauge properly. I ordered a 12V Bosch Blue Coil and waited.

The last time I drove the car was with the Remy Delco coil that came in it. I drove it about 30 miles and came home to install the new Bosch coil. Thinking that my problems would soon be over I turned the key but the car would not start. It sounded like it really wanted to start and actually did run rough for about 2 seconds and that was it. I tried putting the original coil back on thinking it would run but had no luck.

When I first tried the Bosch coil it was in conjunction with the ballast resistor not realizing that the blue coil has (I think) an internal ballast. Once realizing that the external ballast was not needed it was removed along with the white yellow wire to the solenoid. The white slate wire from the tach was placed to the + side of the coil the result being the same, the engine cranks but will not fire. I put an extra spark plug in the # 1 wire and laid it on the side of the motor to see if there was spark. There was. The fuel pump was just rebuilt and I know gas is getting to the carbs which were also just rebuilt. Fuel, air & spark, all three seem to be present.

At this point I’m at a loss along with a lot of other things. I’m hoping the good people of the JH community who have already helped me so much without knowing it can come to my rescue with an official call for Help! Thanks to anyone who read this all the way through. Believe it or not this is the short story, it’s been a long 2 1/2 years.
Best,
John Ross

Back To Top PM Quote Reply  

 Posted: 03-23-2018 09:51 pm
  PM Quote Reply
2nd Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
Hi John,
Welcome to the wonderful world of Lucas electrics. If it is any consolation, I am an electrical engineer, have played with electronics since I was 12 and have owned British roadsters for over 40 years and the electrical problems still drive me nuts.

First off, if you do not have a multimeter, get one. It does not have to be anything fancy as long as it has AC and DC voltage, current and ohm functions. You will also probably need some extension cords with clip leads long enough to reach around from the engine compartment to the cockpit. You will sometimes need to be able to clip the meter to a ground point as well as to the point being tested in order to make a measurement while trying to start the car.

The biggest problem I have run into is bad electrical connections. Even worse is when they are only sometimes bad. It sounds like this is what you have. First thing is to examine all the connectors in the circuit that is not working. Over time, the connectors become loose, corroded or dirty, making the connections unreliable. Also, the wires going into the connectors also become frayed and break as they are removed and replaced.

You will need wire clippers and wire strippers as well as a crimping tool to replace any of the connectors that look bad.

With the ignition turned on, you should get about 9V-12VDC at the +V connection (not the Hi voltage connector) of the coil, depending on whether there is a ballast resistor in the circuit. When you crank the engine this voltage should be 12V if the ballast resistor bypass circuit is working. When you crank the engine you should get close to 12VAC at the connection between the coil and the points (or hopefully an electronic ignition module). If something is not showing up when it should, you can use the ohm function to find where the bad connection is.

Sorry if this is stuff you already know. I was not sure how knowledgeable you were, so I thought it best to start with the basics. I will check back and give more detailed info if needed.

Tom

Back To Top PM Quote Reply

 Posted: 03-23-2018 10:43 pm
  PM Quote Reply
3rd Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
Oops. Looking more carefully, you may have the new tach wired up incorrectly. The old one was current sensing, the new one is voltage sensing. So the +12V should go directly to the +V of the tach and to the +V of the coil. Then an additional wire should go from the other connection on the coil to the sensing input of the tach. Is this what you did? If not, there may be too much resistance in the circuit going to the coil. In that case, you might get a spark, but it would be too weak to get the engine to run.

Back To Top PM Quote Reply  

 Posted: 03-23-2018 10:47 pm
  PM Quote Reply
4th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
Hi Tom,
Thanks so much for your reply. I do have a multi meter but I never considered the extension cord attachment you described. I will try to make one of those up over the weekend. Unfortunately the ignition is still points. I did have the distributor rebuilt last summer by Jeff at Advanced so everything there is new as are the plugs,plug wires and alternator.

I believe the Bosch Blue coil I purchased has an internal ballast. I am suspect of the coil because this whole problem started when I tried to switch out the Remy Delco coil that came with the car with the Bosch. I have heard that there are some bootleg Bosch Blue coils out there but I don't know enough about them to be able to tell. I will try and test as many things as possible over the weekend as well as clean and re-clean any connections. I will also check the fuse again just to be sure. I have a friend coming over Sunday Morning who has owned a lot of British cars in the past. Hopefully he will be able to help. I will post any findings. Thanks again for your help and guidance.
Best-John

Back To Top PM Quote Reply

 Posted: 03-23-2018 11:17 pm
  PM Quote Reply
5th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
I made a jumper to connect the white yellow wire from the solenoid to the white slate from the tach and connected that to the +V side of the coil. I also ran a second wire from the tach and connected that to the +V side of the coil as well. I have since read here on the message board that if the coil being used has an internal ballast that the white yellow can be eliminated and the white slate wire can go right to the +V side of the coil. Is that where the second (new) wire from the tach should go as well? I will pull the gauge cluster again to see if the wires are as they should be on that end.

Back To Top PM Quote Reply  

 Posted: 03-24-2018 02:14 am
  PM Quote Reply
6th Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
The additional wire to the tach should go to the coil connection that goes to the points. The voltage at this point should switch between 12V and 0V as the points open and close. The Spidya works by sensing these pulses.

Since you have points, you should also have an engine analyser that checks dwell and condition of the points. It is fairly easy to burn the points if they are left closed too long and too much current flows through continuously. You can also check for burnt points with the DMM. I think the spec is that the voltage across the points should be less than 0.2V when they are closed.

I suggest you make an ohmmeter measurement on your coils. Lots of the newer coils are designed for electronic ignitions and have very low resistance, which can quickly damage your points. The new coil's resistance should be about the same as the resistance of the old coil plus the resistance of the ballast resistor. There is a spec for the minimum total resistance for this, but unfortunately I don't remember it any more.

A quick sanity check could be to try starting the car with a quick-start spray and see if that works.

Tom

Back To Top PM Quote Reply

 Posted: 03-24-2018 09:55 am
  PM Quote Reply
7th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
I have a much better understanding of what you are explaining than I did 21/2 years ago but it’s still kinda Greek for me but not totally. That being said, the additional wire run from the tach was definitely not connected to the side of the coil that goes to the points, so that can be switched easy.

I do have on loan from another friend an old Sears/Penske engine diagnostic machine that I think has the functions you describe for the analyzer. Whether or not I can figure it out remains to be seen. Because I’m a novice I need to ask, does the car need to be running to check the dwell and condition of the points? Before I sent the distributor to advanced to get rebuilt I did purchase the rebuild kit from the club store so I think I have another set of points to install if these ones prove to be damaged.

I did try some quick start the other night with no success. Again, my experience with doing that is limited to lawn mower and snow blower carbs and never with this car. I’m a work in progress.

The reason I did not convert the ignition to electronic at the time was cost as there were a couple of other projects going. Maybe the thing to do is just switch it over now and be done with it. Would it be very difficult to do. I have read a lot of posts here concerning the conversion, mostly to Pertronix. The whole points thing sounds like being involved in a dysfunctional high mantinance relationship. Thanks again for your help.

Back To Top PM Quote Reply  

 Posted: 03-24-2018 11:33 am
  PM Quote Reply
8th Post
Rick in Miami
Member
 

Joined: 02-17-2015
Location:  
Posts: 48
Status: 
Offline
Have you checked that the points are still gapped correctly?

Back To Top PM Quote Reply

 Posted: 03-24-2018 12:50 pm
  PM Quote Reply
9th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
Hi Rick
No I have not. I am not exactly sure how to do that but will figure it out and check that.

Back To Top PM Quote Reply  

 Posted: 03-24-2018 09:31 pm
  PM Quote Reply
10th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
I took some ohmmeter readings and came up with the following:
New Bosch coil with internal Ballast - 3.5 ohm

Original Remy Delco coil - 2.0 ohm
Original Ballast resistor - 2.2 ohm
Total - 4.2 ohm
When the new coil was first installed I was not aware of the internal ballast so the external ballast resister was installed as well. If I am understanding this correctly that would have made the total resistance at that time 5.7 ohm.

Back To Top PM Quote Reply

 Posted: 03-25-2018 01:59 pm
  PM Quote Reply
11th Post
Brett Gibson JH5 20497
Member
 

Joined: 03-17-2005
Location: Hilton, New York USA
Posts: 798
Status: 
Offline
You really need to make sure everything is set to spec's, timing, points etc, before you try fixing something that may not be the issue, just saying.

Back To Top PM Quote Reply  

 Posted: 03-25-2018 10:40 pm
  PM Quote Reply
12th Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
Hi John,
Sorry about the slow reply. I have been busy with my own projects this weekend a forgot.

The total resistance for coil+ballast sounds about right for both cases. The exact amount is not that critical, the higher the total resistance, the less chance of burning the points, but lower gives better spark. So i think you should be OK using the new coil w/o the ballast. Just do not leave the ignition on without cranking or running for extended periods.

You should be able to check the points and dwell with the engine analyzer without running the engine. Connect power and ground to the analyzer by connecting to the battery, then connect the sense line to the coil connector that goes to the points. With the ignition on, you should read either 12V or 0.2V depending on whether the points are open or closed. You can get the points to open or close by "jogging" the engine a bit by cranking it for a very short time. If the closed voltage is much over 0.2V you either have a bad electrical connection or the points are bad. If you decide the points are bad, then I would go with swapping in a pertronix ignition. It is actually easier than putting in new points and is not that expensive. On the other hand, if the points look OK, getting everything running as is might be quicker. The pertronix can mess up the spidya tachometer operation, so it is better to do one thing at a time. If the points still look good, then switch the analyser to "dwell" and see what the reading is when you crank the engine. It should be about 60 degrees for this engine.

If all this looks good, the next step would be checking the timing. You need to get a timing strobe light, preferably with an inductive pick up. When cranking and the timing light connected to cyl #1, if the timing mark shows up about 5-15 degrees before top dead center (TDC), the engine should at least run. If you have trouble seeing the timing mark, I suggest painting it with a bit of white paint to make it easier to see.

If this all looks good, we can go on from there.

Tom

Back To Top PM Quote Reply

 Posted: 03-25-2018 11:03 pm
  PM Quote Reply
13th Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 200
Status: 
Offline
If you are going out to buy a timing light, I would also get a remote starter switch. This gets connected between the batter +V and the red/white wire connection on the starter. This lets you crank the engine without going back to the cockpit to turn the key. If the white-yellow wire from the starter is also still connected to the coil, you also do not have to have the ignition on to get power to the coil when cranking. Makes debuggging much easier.

Back To Top PM Quote Reply  

 Posted: 03-25-2018 11:50 pm
  PM Quote Reply
14th Post
johnfalveyross
Member
 

Joined: 08-21-2015
Location:  
Posts: 8
Status: 
Offline
Hi Tom,
Thanks for explaining how to use the analyzer. My friend came over today and after trying a few things we pulled the distributor and the points were cooked, well done cooked. I had purchased the rebuild kit from the club store prior to getting the distributor rebuilt at Advanced so I had an extra set of points and condenser. I believe we gapped them correctly. We reinstalled the distributor and tested to see if we had spark by pulling the #1 plug wire and installing an extra plug. We had no spark. We used the multi meter and tested the to see if we had power at the coil while cranking which we did. My buddy was reading the multi meter and He said it was reading 11.4v. I tested the battery and got a little over 12.

Fortunately I do have a timing strobe light so if I ever get it running again I’ll be able to time it. I am going to get a different coil because all these problems started when I tried switching over to that Bosch coil. The car was running good prior to that. Once the new coil gets here I’ll have a go at the tests you described with the analyzer and hopefully gather some useful data.

I pulled the gage cluster and cleaned all the connections and added some dialectic grease. Not the end of the weekend results I was hoping for but I know more than I did on Friday. Thanks for your help.

Back To Top PM Quote Reply

Current time is 01:20 pm  
> Jensen Healey & Jensen GT Tech > Fuel Stuff > Electrical Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems