MPX4250AP MAP Sensor suitable for Fuel Pressure ?

[Spockie-Tech]

I am working on a few extra sensing systems for my Triple Weber Hemi (with Megajolt of course ) and am wondering if anyone has an opinion on the idea of using the MJLJ Map sensor as a low-pressure fuel-pressure sensor.

Webers like running between 3-4 psi fuel pressure, and finding an electronic sensor that will go that low and not cost hundreds of dollars seems to be quite difficult.

Plus, I'd like to run one per Carb, as I have in mind metering the flow to each carb seperately (I have some flow sensors as well).

I'm also thinking of being over-the-top and adding one to each intake runner for individual vaccum readings to make an electronic carb balancer system with a funky LCD pressure wave display..

So, given that this little sensor is presumably rated to handle boost pressure wet (fuel) manifold air, I'm hoping it wont be bothered by a few psi of fuel.. Anyone have any thoughts on that ?

For those that havent seen the Oz Hemi 6 - Heres the 6-Pack 265 Hemi



regards

Brett

[brentp]

At first blush, no; I would say it's primarily designed to measure air. I think Freescale would've designed it differently it the target was measuring fluid pressure.

You may want to browse their website to see if they have something suitable..

Nice carbs by the way! The webers going on my 240z won't be nearly as pretty..

[alexander]

I'm also thinking of being over-the-top and adding one to each intake runner for individual vaccum readings to make an electronic carb balancer system with a funky LCD pressure wave display..

Brett

on this point, i think you will find that the air pressure in an individual runner has a huge pulse in it, down near idle.

alexander.

[Spockie-Tech]

Thanks Brent, I'll have a poke around the freescale site..

Alexander - I'm expecting it will be fairly pulse-like, which is why I am considering a kind of 6-trace overlapping oscilloscope display unit.

It seems that a preferred tool (for the pro tuning shops anyway) for balancing and tuning webers is a big box of dampened vacuum gauges - one for each throat. I was thinking about updating that bit of test gear a bit with this idea.

[DannyP]

Spockie, I have dual Weber 44IDF on a type1 VW. It is no big deal to sync the carbs with one of the modern snail gauges. I mean you only have two more throats than me anyway. It looks like you have a nice big AN line feeding your carbs. The pressure will be the same across all three bowls, use one mechanical gauge if you must, you're right they won't tolerat more than 3.5 psi. Good luck, looks like a really great project.