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MAP question - old firewall mount vs throttle body mount

lunghd

NAXJA Forum User
In the midst of assembling my stroker & the throttle body I picked up has the MAP mounted to it's lower flange where my 90XJ has the MAP on the firewall behind the head.

Q - Does anyone know if these two MAPS have any different operating characteristics or any reason I can't toss the old firewall MAP & run the one mounted to the throttle body?

While very different physically, the connection plug appears the same minus the vacuum port (which on the throttle body MAP goes directly into the tb flange).

My plan is to just make a jumper harness to connect the throttle body mounted MAP to the OEM connection on the firewall (along w/ an integral MAP adjuster while I'm at it...)

Make sense or am I smoking crack again? :greensmok
 
I prefer the firewall-mounted MAP sensor for two reasons; it's out of harm's way and less likely to get drowned if you're fording through water, and also because the vacuum signal from the intake manifold is stronger than it is from the TB.
Just keep your old MAP sensor and plug the vacuum port in the TB.
 
Hey Dino - appreciate the input.

I dunno, I'm thinking that they designed the MAP to work where it's at.
Actually, that probably makes my initial question moot as any differences in behaviour would (I think...) be designed to compensate for the differences in mounting / vac sensing. Hmmm. That would mean any comparison between the two is 'meaningless' unless they were to be mounted at the same location under same conditions. Unless I'm leading myself off the path again...

Drowning shouldn't be an issue for the MAP - I'll be more worried about ME if the water gets that high!

Edit- Both MAPS have similar designs on other vehicles - maybe that's the better question... is there a 'reference' where one can look up the stats / data on various MAPS using the same design externally.
 
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