Hello, Im looking for opinions, I have a aem electrical FP gauge and it fluxuiates alot, I personally dont thing its very accurate, I used a gauge today off the schrader valve, it was just a small gauge i took off a FP regulator, but the pressure was steady, it wasent fluxuating at all, Which is more accurate, keep in mind im looking for a gauge for inside the car, Would a full sweep analog gauge be more accurate than a digital gauge

 

600hplt1sm:
Check your wiring and connectors. Also, try to install the sensor on the supply line as far from the FP regulator as possible to minimize any pressure effects of the regulator loading and unloading. The isolators for analog pressure gauges are notorioius for unreliable readings and as you apparently are aware, direct connection fuel lines in the cockpit are dangerous. Electric it needs to be.

 

Are you really asking about "analog" (sweep needle gauge face) vs "digital" (LED digital reading gauge face)? Or are you asking about "mechanical" (tube of fuel runs to the gauge and drives the needle on the Bourdon tube) vs. "electronic" (pressure transducer mounts in the fuel line, wires run to an electronic gauge)?

I've never tried a digital, but it would seem that the reading would "appear" to fluctuate more than the analog needle, because its reading out in a whole number that is changing rapidly in 1psi increments. The needle is going to be dampened slightly by the mass of the needle, and its tiny movements (still only 1psi) are not going to be perceptable. Comparing a digital reading to the super-tiny movements you would get in a very small gauge off a regulator would make the difference "appear" even larger.

How much fluctuation are you getting? What is the range of the pressure you are observing under steady-state condition?

 

Sorry I was asking about a needle sweep electric vs. a digital gauge. My fp with the aem gauge fluxuiates from 39 to 50 constantley, when i tried the small regulater gauge off the schrader valve to pressure stayed steady at 45-46.

 

Where is the electronic pressure sensor mounted? Any chance its subject to excessive vibrations from the engine?

I have an AutoMeter analog/electronic gauge with the sensor mounted in a bung welded to the passenger side fuel rail, and don't have any problems with it. Pressure is rock steady. But I suspect some of the cheapie ricer gauge senders might be a bit more prone to problems with vibrations. I don't know anything about the AEM stuff.

 

Ok. The sensor is under the pcm, & now that i think about it before i unhooked it the sensor was just laying aganist the metal, when i put it back in i layed a towel down there and the sensor is laying on a towel now, when i started the car today and drove it around the block the gauge read steady so maybe it was the vibration, Oncew i get my pcm back i will test that theory & i already have a fitting with a gauge port going on my new parallel rails so this sensor will go to that port on the new setup