Map Sensor Relocation to passenger side? And removal of FPR control solenoid?

Hi im waiting to do a intake manifold swap to a b18b intake manifold and the throttle body has the map sensor.
I would really like to use that one since I read they do get a better reading, and itll look cleaner if I can remove that bracket from the firewall.
What would be the best way of doing so?
Would the dash need to be removed or do they make harness’ that will allow me to just plug in and run without having to mess with all the wiring?
I would much rather get an obd1 aftermarket harness where all the plugs would already be set up.
Problem is, i dont know if anyone makes them.

ALSO, is the FPR control valve (next to the EVAP purge valve) required to run? I know honda put it there for a reason, but im not too sure if its really needed. Thank you.

For the MAP sensor all you gotta do is cap off the vacuum line from the manifold. The plug should be the same for both the firewall and TB mounted sensors, so no need to alter the wiring (depending on placement you may need to cut back the loom a little to reroute the wires, but you shouldn’t need to add any length).

Here’s what mine looks like:

Project 896_112110_0039 by C o l i n, on Flickr

Thank you for the replay and picture sir, i appreciate it.
The problem Im having is that its too short to reach all the way to the throttle body.
So thats why I was wondering If i have to go under the dash and pull the wiring and run it from a different location.
Also, that soenoid in the picture, is that the evap? If so, is it ok to not use the fuel pressure regulator solenoid?
Thank youagain.

Did you open up the loom like I said in my previous post. I don’t remember for sure, but I don’t think I cut the MAP sensor wires, I simply opened up the loom and changed where it exited the harness to give it more room to reach the TB. You’d be spending a lot of unnecessary time if you pulled the wiring from the dash. If you can’t get it to reach the TB by opening up the loom like I mentioned, then you should just cut and splice in a few extra inches of wire, then wrap it all up again. That will be MUCH easier than ripping the harness open all the way thru the firewall and under the dash.

Yes, the solenoid in the picture is for the EVAP canister. I’m not sure about getting rid of the FPR solenoid, I’ve never tried removing it. My car is a GSR so it doesn’t have a FPR solenoid like the b18a equipped DA’s do. Read thru your Helms and see exactly what the solenoid does and if it will throw a CEL if it’s removed. That should give you some insight as to whether or not you can just remove it or if you need to do some other mods first in order to get rid of it.

Colin your bay is so nice. Off topic I know but so nice!


Yes sir i started pulling the wires out of the loom and it started to get hard to get to so i stopped because I was running out of time.
But so far it didnt reach.
Do you happen to know if the wires go inside the the cabin or not?
Thats pretty much all I need to know to see if my only choice is to cut and solder extra wire. I hate to but I see what u mean bout it being a waste of time.

And this is what i got about the FPR valve:
“Fuel Pressure Regulator Control Solenoid Valve (B18A1 Engine)
When the engine coolant temperature is above 196 degrees F (91C) and the intake air temperature is above 165 degrees F (74C), the fuel pressure regulator control solenoid valve is energized, cutting manifold vacuum to the fuel pressure regulator for about 60 seconds after starting engine.”

Thanks guys. I’d be lying if I said I didn’t put a lot of work into it. It’s not flashy or trendy, but it’s tidy and doesn’t look very modified which is what I was going for.

da9cris909: Yes, it does go into the cabin. Off the top of my head I’m not sure the routing of all 3 wires, but I know at least one leads to the ECU. I just looked thru my pics but I can’t find any indication of whether I added length to mine. I know that I changed the connector from the cream color to a grey one from a DC2 engine harness but I can’t remember if I added length as well.

One thing I had forgotten about until now is that the MAP sensor wiring goes thru the engine wiring harness, it isn’t just part of the main harness. This means that the wires run from the MAP sensor into the engine wiring harness, then to a connector on the end of the engine harness. That connector connects to a connector on the main harness, from the the wires run to the ecu and anywhere else they may go (again, I’d have to look at the Helms to confirm exactly where). So, what does that mean? It means that making any changes on the main harness side of the MAP wiring will NOT help get you length to connect your sensor. If you need to add length, you need to do it within the engine harness for it to help your problem.

I never looked into what the FPR solenoid actual did and why but judging by what you wrote, it changes fuel pressure when ECT’s and IAT’s are high and you’re starting the car. I’m not 100% sure why but it’s a fairly special case scenario seeing as those temps are pretty high. I’d expect it isn’t very important but I’d look into it a little more closely before changing anything. And now that I see you’re in CA I wouldn’t remove it at all, it’s illegal. I’d relocate it if you must get it out of the way. I’d look to see if there’s an easy place to mount it under the intake manifold and then whenever you have to do your smog checks I’d move it back to the firewall.

Nice, so pretty much im able to move the map sensor around because its in the engine main harness?
Not easily of course, but if I were to have a spare harness to re-do or even mod an mpfi 88-91 civic harness?

And as for the fpr solenoid, by the writing i posted it seems to me also it may be useless.
Ive seen lots of people with swaps and tucks that removed the solenoid so I didnt think it was too bad, but never hurts to be too sure.
Smog visual isnt too bad for me as I have a person I always take it to.
I know that sooner or later I wont as its getting more strict, but I still do make strides to pass emissions at least.

And I do agree with everyone else. Very clean bay

[QUOTE=da9cris909;2239791]Nice, so pretty much im able to move the map sensor around because its in the engine main harness?
Not easily of course, but if I were to have a spare harness to re-do or even mod an mpfi 88-91 civic harness?
Not sure exactly what you mean by “move around” or how using a spare harness or an EF harness would help you. As I see things, there are only 2 options, which I mentioned before; 1) strip back the loom and see if you can get some more slack in your MAP wires by having it exit the harness at a different point, or 2) strip back the loom and actually extend the wires by soldering in some extra wire. If you have a spare harness then you could use the correct wire colors (I did this a few times in my harness).

Thank you. I’ll take that as a reason to whore it out a little with a better pic.

Project 896_051610_0005 by C o l i n, on Flickr

I could look at it all day.

i agree with everyone. CLEAN shit man

LOVE the bay, Colin… first time I’ve seen it. I need to search for a possible build thread of yours heh.

As far as the OP… if its THAT hard to de-loom the harness, just add 6" of length to the three wires and be done with it. Pulling wires through the firewall, or using a separate harness, etc etc sounds like a complete pain in the ass.

Either do what Colin said and de-loom the harness and re-route the MAP wiring, or solder in some new wire. Simple enough.

Alright colin now I fully understand. Sorry I got a little confused with 2 of the sentences. But thank you for all your help, I really appreciate it.

And man is that mint. Just seeing and overflow that clean amazes me lol.

Haha, thanks guys. Just remember, pics hide SO MANY flaws, lol. There’s no build thread on any public sites, I wasn’t really looking for internet attention while building this car, just trying to put together something fun for the race track. I do have a ton of pics online, but they’re mostly just documenting stuff that I need to be able to reference and want handy. You’re more than welcome to peruse, but there’s probably not that much of interest.