2nd Gen Non-Engine/Transmission SPA gauge problems

[Nickaru]

My SPA Fuel pressure gauge reads with a minus in front of the number at times. Also, my EGT red light comes on and no EGT reading is present. I checked the senors and they're all tight. Do I have bad gauges/ sensors? One more question, how do you reset the high limits? When I get into the truck and check them, they are the same highest readings when I first put the gauges in last year sometime. I read somewhere that they reset every time the ignition is turned off. I have them wired to ignition only. Any ideas, Thanks... ...

 

[LSMITH]

To reset the peaks hold the button in and turn on the ignition, you will see something like bl/on ( the / is top and bottom), push the button until you get something like rt/pe, when you get that hold the button in until it automatically scrolls to the next menu item. Turn off the ingnition and back on normally, the peaks should be reset. The peaks are stored until they are reset manually, and will only change if you reset them or set a higher peak. A feature my wife hates, prompts me to ask just exactly why she needs 34 PSI on the eay to the store and back!!! If all else fails read the book, the instructions are not too clear but should get you through it.



As far as the FP going negative, are you sure it isn't actually going negative? It is pretty common with clogged filters and failed lift pumps.



Not sure what you mean on the EGT warning coming on with no reading, is it below your set point or is it when the gauge is off or what?

 

[Bigsaint]

I get the - next to the FP reading once in awhile when I key on ( wait to start). If that's what you are seeing, you just need to re-zero the gauge. Another thought is your grid heaters. When I key on and wait to start in the extreme cold ( below 10f), the grid heaters draw so many amps. that the SPA gauge reads low voltage . Perhaps that is what your are seeing.



If you don't have your SPA manual handy, send me a PM and I'll walk you through the resets.



Scott W.

 

[JCyrbok]

Negative

Occasionally my SPA boost gauage will read huge (-20) negative boost numbers. I checked everything and found that the wires that they used for the gauages is somewhat weak and that the connections get kinda loose over time. Occasionally mine does it if I hit a big bump in the road. I "fixed" it by reinforceing the connections with electical tape and no longer have the problem.



J-

 

[TomGolden]

Ever since I had my SPA Series 2 gauges installed 9 months ago,

I ocassionally get really bs readings on several of them. My

engine oil temp and fuel pressure are the worst. I see -71*F on

engine oil temp and ocassionally negative fuel pressure values.

My solution was to shoot all the connections full of dielectric

grease. Ocassionally I still have to reseat the connections, and

then all works normally.



Tom

 

[Bigsaint]

Another thought, following up on Tom's reply... it's a good idea to check the connections at the wiring harness elbow for the psi sender. I pulled mine apart at Brandons direction when I snaked the wires through the firewall. You will see that the connections are very scant and could easily lose contact.



Scott W.

 

[Little Bill]

I ended up soldering the leads directly to the male tabs on the fuel pressure and boost pressure senders. Did that 1. 5 years ago and haven't touched them since. Prior to soldering I had to tweak the connectors in female side every 3-4 months. Not what you would call a robust connection. Last week the EGT started acting up. Tweaked connections in the female T/C connector, shot it full of dielectric grease and it went back to work.

 

[JohnMcIntyre]

Negative readings on SPA gauges

Nickaru,

I just read this thread and don't think anyone has responded with this specific information, which I personally came across from the SPA manufacturers themselves in England back in the summer of 2001. I have the original SPA Mk. 1 units with fixed level backlighting (but this information relates equally to the Mk. 2 units as well).



If you follow the set/reset instructions detailed by {ScottW} and {LSmith} earlier in this thread, you should carefully check the value currently set for your "sampling time". In other words, the time delay between subsequent "snap-shot" measurements of the current fuel pressure value being taken by the fuel pressure sensor and then recorded by the SPA gauge itself.



I reckon there's a good chance you've probably still got the original SPA factory default setting, which is measured in terms of fractions of a second and you should consider increasing the elapsed time between these "snap-shot" measurements, because the SPA gauge is rendering these same "snap-shot" values into an averaged readout on your gauge. A bit of experimentation may be neccessary but a good starting point for the sampling interval is around <1 sec>.



A second factor to consider is the physical location of the fuel pressure sensor and it's relative proximity to the fuel pump housing itself. The SPA gauges (Mk. 1) are VERY sensitive to fuel "surging" and this can reflect in some spurious negative (as well as positive) readings. The nearer the sensor is located to the Fuel Pump housing, the more noticeable the surge effect on the SPA gauge readout will likely be.



Now if you combine some (or all) of these factors together. you'll understand why you're getting some yoyo readings occasionally. Understanding the WHY and HOW is the first step to resolve this issue.



Hope this helps!!