Home 
Home Search search Menu menu Not logged in - Login | Register
> Jensen Healey & Jensen GT Tech > Electrical & Instruments > Piranha ignition and tach reading low

 Moderated by: Greg Fletcher
New Topic Reply Printer Friendly
Piranha ignition and tach reading low  Rate Topic 
AuthorPost
 Posted: 06-19-2021 02:11 pm
  PM Quote Reply
1st Post
tallyhoe
Member
 

Joined: 08-17-2014
Location:  
Posts: 29
Status: 
Offline
This is an older electronic ignition and I can't find any info on how to adjust or diode the beast to read correctly. Has anyone used/kept their Piranha spark box?

Back To Top PM Quote Reply  

 Posted: 06-19-2021 04:15 pm
  PM Quote Reply
2nd Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Stock Smiths tach? Those are current triggered and a source of problems. Get one of the RVI to RVC tach conversion boards and remove a source of annoyance from you car: https://spiyda.com/smiths-rvi-rvc-conversion-board.html

--
Joachim

Back To Top PM Quote Reply

 Posted: 06-19-2021 05:13 pm
  PM Quote Reply
3rd Post
tallyhoe
Member
 

Joined: 08-17-2014
Location:  
Posts: 29
Status: 
Offline
Thanks.
Jay

Back To Top PM Quote Reply  

 Posted: 06-19-2021 06:24 pm
  PM Quote Reply
4th Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
The mechanism could probably do with a cleaning too, if it seems sticky. That could be the reason that tapping on it makes it come down. I didn't clean mine because I couldn't get the needle off, didn't want to risk breaking it.

Back To Top PM Quote Reply

 Posted: 06-19-2021 07:29 pm
  PM Quote Reply
5th Post
tallyhoe
Member
 

Joined: 08-17-2014
Location:  
Posts: 29
Status: 
Offline
I actually have to tap it to make it kinda work, but cleaning sounds like a good start.

Back To Top PM Quote Reply  

 Posted: 06-20-2021 03:51 pm
  PM Quote Reply
6th Post
DonBurns
Member
 

Joined: 09-18-2015
Location: Fullerton, California USA
Posts: 147
Status: 
Offline
I tried doing the spiyda conversion, and failed. You have to remove the needle and mine was very resistant and I think I ended up damaging the mechanism. My speedometer was also not reading right. I replaced both with Speed Hut units, that you can custom order faces and bezels for to pretty closely match the original look. They work perfectly and I am happy I went that way. Speedo is by GPS so you can remove the cable to the transmission, which also simplified the W58 installation. Also way cheaper than estimates I found to rebuild the Smiths. I've kept them just in case I ever feel the need to reinstall the originals. Don't see why I would, though.

Back To Top PM Quote Reply

 Posted: 06-20-2021 06:21 pm
  PM Quote Reply
7th Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
You dont have to remove the needle, I chickened out on that because it felt stuck. Still made the conversion, no problem.

--
Joachim

Back To Top PM Quote Reply  

 Posted: 06-21-2021 10:54 pm
  PM Quote Reply
8th Post
Tom Bradley
Member
 

Joined: 07-15-2013
Location:  
Posts: 203
Status: 
Offline
There is an adjustment screw in the stock tachometer accessible via a hole in the back of the case. These guys tend to age and go out of calibration. Its a pain to adjust, though.

I also did the conversion to Spiyda without removing the needle, but I did not think it was easy at all.

Back To Top PM Quote Reply

 Posted: 06-22-2021 06:32 am
  PM Quote Reply
9th Post
subwoofer
Member
 

Joined: 04-01-2008
Location: Sandefjord, Norway
Posts: 617
Status: 
Offline
Hehe, I should have added a "YMMV" after "no problem". I find soldering surface mount electronics easier that through-hole, particularly when modifying circuits. I guess it's just what I have the most experience with.

As for the stock tach, if I remember correctly there is an electrolytic capacitor in there, that one will have nowhere close to it's original capacity by now. Also, the solder joints and the PCB are all likely to be well flaky by now.

If the needle sits at 0 and jumps into life when you tap the tach, I would say the problem is electronic. If it freezes or seems to stick in any random position and tapping it gets it going again the problem is mechanical - it needs a clean.

Tweaking the calibration screw will be very unlikely to improve matters.

--
Joachim

Back To Top PM Quote Reply  

 Posted: 06-22-2021 12:30 pm
  PM Quote Reply
10th Post
tallyhoe
Member
 

Joined: 08-17-2014
Location:  
Posts: 29
Status: 
Offline
It is dead until I tap it. Hopefully I will get to it this weekend. Thanks

Back To Top PM Quote Reply

Current time is 09:22 am  
> Jensen Healey & Jensen GT Tech > Electrical & Instruments > Piranha ignition and tach reading low Top




UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems