Alky Pump Pressure Gauge Failing

[hemi8]

I have a alky pump pressure gauge from Razor, it has been working for about 1k miles but now it just radomly jumps to 150psi and lights up while I'm idling at a light or just driving along. Has anyone else with this gauge experienced this problem (are the senders for these gauges NFG)?
Mike

 

[TR Custom Parts]

Sounds like it might be a bad connection? I have had a couple transducers fail over the years. Were you also using a Powerlogger to log alky pressure?

 

[Jerryl]

I have a alky pump pressure gauge from Razor, it has been working for about 1k miles but now it just radomly jumps to 150psi and lights up while I'm idling at a light or just driving along. . . . . .

I do not have the gage . . . but if it "lights up" (Ass-U-Ming you are taling about the alky system action light) . . . the system is running which is why the pressure spikes. Not sure the gage has anything to do with that since it only indicates what it is seeing.
Does the car stumble when this happens and what are the O2's doing when tis happens?

 

[hemi8]

The light I am refering to is the gauge light which comes on when the alky pump is operating. Only thing is the pump is not operating, the gauge just randomly swings to 150 psi and gets stuck for a while. The alky system works perfectly, the gauge is malfunctioning. I have no reason to belive it is a connection problem, it has been working fine for the last 8 months. Is anyone who uses this Marshall gauge since Razor put it out there having similiar problems with it?
Mike

 

[TR Custom Parts]

Do you have the test button installed? When you press that button the gauge will do what you describe.

 

[hemi8]

Yes I do, but I did not push it so it should not swing to 150psi randomly.
Mike

 

[TR Custom Parts]

Bad button? Try pressing it a few times and see what happens.

 

[jmendlik]

Call Julio and get a new transducer-mine went out last week and was showing similar issues....Got a new unit and back to Normal...

 

[hemi8]

Doesn't say much for quality if they are failing this fast.
Mike

 

[Razor]

Doesn't say much for quality if they are failing this fast.
Mike

Well you need to see where the problem lies. Is it the transducer? Is it the gauge? Bad connections on the transducer or where they attach to the regulator.

Need to troubleshoot what the problem is and then go from there. I havent had any bad gauges.. transducers a few have failed. But lets not condemn it until you have data. I havent seen any fail as you describe. Joe's was leaking. Marks didnt change output. I attributed Marks to connections to the PL.

Simple test.. unplug the transducer and gauge should go to zero. And stay there. If so... then troubleshoot sensor and its wiring.

Could be a simple bad ground connection on the black wire whether at the plug on the sensor or its connection to the 5v regulator under the dash. If the sensor loses ground, it will peg the gauge.

Post back... we only learn from failure. And understand transducers are typically used for industrial applications. At the 100 dollar range on sensors.. these are at the bottom of the feeding curve. Most "good" units are in the $1k+ range as they are used for automation process.

 

[TR Custom Parts]

Julio, want to clarify, on mine wasn't a bad connection to the PL just the fact that it was connected to both the gauge AND the PL. I did have a previous one fail when it was only connected to the PL as well.

 

[Razor]

Julio, want to clarify, on mine wasn't a bad connection to the PL just the fact that it was connected to both the gauge AND the PL. I did have a previous one fail when it was only connected to the PL as well.

Understood and thanks for the clarify. Yours appeared to have had an output drive circuit problem. Like too much load posed on the sensors output capabilities.

I'll be making a circuit soon to take the load of the transducers drive circuit for situations that run multiple things of one sensor.

Julio

 

[TR Custom Parts]

Miss being able to log the pressure as well as using the gauge.

 

[hemi8]

Thanks Razor, I'll follow the troublshooting path. I am doing a new exhaust this weekend so I won't be driving it till next week sometime.
Mike

 

[hemi8]

After many new mods this summer I have been driving the car for the past few months on nice weekends and am seeing prblems with the gauge again. Now its not stuck at 150 anymore it just randomly does not work. When I hit the test button on the alky control sometimes the gauge responds, most times it does nothing, I know it is injecting alcohol by watching the A/F dip when I hit the button and the engine wants to stall. What to check first?
Mike

 

[Razor]

After many new mods this summer I have been driving the car for the past few months on nice weekends and am seeing prblems with the gauge again. Now its not stuck at 150 anymore it just randomly does not work. When I hit the test button on the alky control sometimes the gauge responds, most times it does nothing, I know it is injecting alcohol by watching the A/F dip when I hit the button and the engine wants to stall. What to check first?
Mike

You need to get to basics.
You have a transducer that through changing voltage causes a gauge to change. The gauge is basically a fancy DC voltmeter. So what to do..
Simple. Get a DC voltmeter and read the signal on the transducer. The transducer has 3 wires. 5v, ground, and signal. See what the signal does. It should be .5v key on no pressure on sensor. When you hit the test button the voltage should move from .5 up. Every bar(15 psi) is .4 volts. So for example.. 30 psi pressure is 1.3 volts.
So if you push the test button and see the voltage go to 1.3, the meter should go to 30 PSI. At this point you will have your answer whats not working and then a direction to solve the issue. You hadn't posted since August on the issue..
If the transducer moves and meter doesn't.. then we troubleshoot the meter. Or if the transducer doesn't move.. then we troubleshoot power to the sensor or the sensor itself.

Mark.. haven't forgotten about ya,

 

[hemi8]

Thanks Razor, I'll monkey with it over the holidays and let you know what I find.
Mike