SUPPORT OUR SPONSOR

Go Back   Club Cobra > Club Cobra Tech Areas > Shop Talk

Welcome to Club Cobra!  The World's largest non biased Shelby Cobra related site!

  •  » Representation from nearly all Cobra/Daytona/GT40 manufacturers
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and nearly 1 million posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

MMG Superformance
Nevada Classics
Main Menu
Nevada Classics
Nevada Classics
MMG Superformance
Keith Craft Racing
Advertise at CC
Banner Ad Rates
MMG Superformance
MMG Superformance
MMG Superformance
January 2021
S M T W T F S
          1 2
3 4 5 6 7 8 9
10 11 12 13 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30
31            
  #1 (permalink)  
Old 01-10-2020, 08:34 PM
ERA 626's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Sep 2001
Location: Danville, CA
Cobra Make, Engine: CSX 6079 482CI CSX cross ram
Posts: 1,201
Not Ranked     
Default electronic smith oil pressure gauge

Here is the issue:
I have a brand new electronic Smith oil pressure gauge I got from nissonger.
I wired it up exactly per instructions, This is a new motor build so there is no oil in the block it is just a mock up at this point.

When I turn on the key the gauge goes to 95 PSI and stays there. I tripple checked the wiring ( hot, ground, sender input) it is all good.

I called nissonger and he told me that it could be a grounding issue to the sender, this makes no sense to me because the gauge has a ground wire running to the sender, so I also grounded the sender to the chassis ground, same issue. Same result if I disconnect the sender, so to me this rules out the sender.

I had him send me a new gauge, same thing. So I turned on the key and applied an air compressor to the gauge to see if I get a reading, when I do this the gauge goes to 100psi then back to 95 PSI... Is this normal? I need advise on this.

Last edited by ERA 626; 01-10-2020 at 08:41 PM..
Reply With Quote
Sponsored Links
Sponsored Links
  #2 (permalink)  
Old 01-10-2020, 10:17 PM
spdbrake's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2015
Location: Lyman, SC
Cobra Make, Engine: BDR #53
Posts: 1,034
Not Ranked     
Default

I assume you are using the the Smiths pressure sender and not the Autometer sender that came with your factory gauges?
https://www.petrolheadheaven.com.au/...ra-gauges.aspx

If so there should be only one wire going to the sender and its not a floating ground type so needs no strapping to ground. The NPT fitting should handle that (unless you have a lot of Teflon tape on it, actually you shouldn't use any).
I'd start by using a meter on the SMITHS sender and reading the OHMs from the spade connector to case. It should read one of the range specs for your particular sender. EX: 33 ohm engine off, 240 ohm full sweep. (Those are VDO numbers I'm throwing out)
Also disconnecting the the sender the gauge should peg at full sweep.

Last edited by spdbrake; 01-10-2020 at 10:19 PM..
Reply With Quote
  #3 (permalink)  
Old 01-11-2020, 10:14 AM
CC Member
Visit my Photo Gallery

 
Join Date: Aug 2007
Location: Carlsbad, Ca
Cobra Make, Engine: SPF 2932 with 438 Lykins Motorsports engine. Previous owner of FFR 5452.
Posts: 2,497
Not Ranked     
Default

My gauge has a ground wire from the gauge that I grounded to a nearby chassis bolt.
__________________
Jim
Reply With Quote
  #4 (permalink)  
Old 01-11-2020, 11:58 AM
ERA 626's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Sep 2001
Location: Danville, CA
Cobra Make, Engine: CSX 6079 482CI CSX cross ram
Posts: 1,201
Not Ranked     
Default

Quote:
Originally Posted by spdbrake View Post
I assume you are using the the Smiths pressure sender and not the Autometer sender that came with your factory gauges?
https://www.petrolheadheaven.com.au/...ra-gauges.aspx

If so there should be only one wire going to the sender and its not a floating ground type so needs no strapping to ground. The NPT fitting should handle that (unless you have a lot of Teflon tape on it, actually you shouldn't use any).
I'd start by using a meter on the SMITHS sender and reading the OHMs from the spade connector to case. It should read one of the range specs for your particular sender. EX: 33 ohm engine off, 240 ohm full sweep. (Those are VDO numbers I'm throwing out)
Also disconnecting the the sender the gauge should peg at full sweep.
I am using the sender nissonger sent me, it is a variohmEPT2100
https://www.variohm.com/contentfiles...sor_1907_O.pdf

It looks as if it puts out a voltage of 0.1-5v

the sender is ouputting 2VDC with 0 oil pressure. This is a concern because I am putting in a BRAND NEW MOTOR and the oil pressure gauge MUST work...

what is driving me nuts is:
when I turn on the key it goes to 95PSI and stays there( it seems to gidder a little like it is sensing 95PSI of pressure) When I disconnect the sender it goes full sweep 100PSI, When I put an air compressor on it it jumps tp 100PSI and then back to 95PSI. Please note that the sender is NOT connected to the motor, but I did make sure the case is grounged to chassis ground. The gauge has 3 wires 1) ground 2) key hot) 3 sender output. why is it sitting at 95psi when key on? is this normal because there is no oil ? no clue

Last edited by ERA 626; 01-11-2020 at 12:30 PM..
Reply With Quote
  #5 (permalink)  
Old 01-11-2020, 01:21 PM
RockBit's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Jun 2014
Location: Dallas, TX
Cobra Make, Engine: ERA #812 427/482 FE
Posts: 437
Not Ranked     
Default Smiths Electronic Gauges

Mike:

Here is a wiring diagram for Smiths electronic gauges. My oil pressure gauge works fine. The sender I have is the one listed by speedbrake above.

There are four wires coming out of the gauge:

Black - to chassis ground
Red - to the instrument light rheostat, for the light
Green - switched power (+12V)
White/Blue Stripe - to the sender

The sender has no ground, as it grounds through the threads. Be sure the sealant is not electrically insulating.

The gauges sweep through their motion when the key is turned on, then sweep back to zero. I don't have my car, so I can't do any tests or measurements for you at the moment.

Good luck.
Attached Images
 
__________________
Chris
Reply With Quote
  #6 (permalink)  
Old 01-11-2020, 02:29 PM
spdbrake's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2015
Location: Lyman, SC
Cobra Make, Engine: BDR #53
Posts: 1,034
Not Ranked     
Default

Wow, The transducer they sold you has a variable voltage output.

The gauge is looking for variable OHMs input.

The Smith Sender PN PTR1000-6-10 shown on all the sites I can find says it works with the Smiths Oil press gauge PN APG1310-02C.

The Smiths sender Ohm range is 300-10 ohms.
https://www.smiths-instruments.co.uk...re-transducers

I'd contact Nissonger and request an explanation on how the gauge is going to covert the voltage to a usable reading. I may be missing something totally here but it doesn't feel like it. Whats also weird is the Nissonger site lists the PTR1000-6-10 sender.

I must admit the transducer is working since you do have a gauge scale reading, its just off quite a bit. So either the transducer is faulty or they sent you the wrong one I'm guessing.

Last edited by spdbrake; 01-11-2020 at 03:17 PM.. Reason: added info
Reply With Quote
  #7 (permalink)  
Old 01-11-2020, 04:04 PM
ERA 626's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Sep 2001
Location: Danville, CA
Cobra Make, Engine: CSX 6079 482CI CSX cross ram
Posts: 1,201
Not Ranked     
Default smith

Quote:
Originally Posted by spdbrake View Post
Wow, The transducer they sold you has a variable voltage output.

The gauge is looking for variable OHMs input.

The Smith Sender PN PTR1000-6-10 shown on all the sites I can find says it works with the Smiths Oil press gauge PN APG1310-02C.

The Smiths sender Ohm range is 300-10 ohms.
https://www.smiths-instruments.co.uk...re-transducers

I'd contact Nissonger and request an explanation on how the gauge is going to covert the voltage to a usable reading. I may be missing something totally here but it doesn't feel like it. Whats also weird is the Nissonger site lists the PTR1000-6-10 sender.

I must admit the transducer is working since you do have a gauge scale reading, its just off quite a bit. So either the transducer is faulty or they sent you the wrong one I'm guessing.
on smiths web site it says this
"We also have an electronic version that is identical PG1310-00CB, that will work with a motorsport sender PTTR2300-10-8NKIT"

this is the gauge I have. PG1310-37CB I am thinking the sender is bad as it is putting out 2vdc with 0 oil pressure.

Last edited by ERA 626; 01-11-2020 at 04:26 PM..
Reply With Quote
  #8 (permalink)  
Old 01-11-2020, 06:57 PM
spdbrake's Avatar
CC Member
Visit my Photo Gallery

 
Join Date: Dec 2015
Location: Lyman, SC
Cobra Make, Engine: BDR #53
Posts: 1,034
Not Ranked     
Default

I think you're correct on sender being T.U. then.
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 10:18 AM.


Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: CC Policy