Fuel regulator solenoid issues...

[JEBB4]

I've been driving my H22A swapped bb2 around for a while with the fuel pressure regulator vuccum pipe going straight to the port on the inlet, it wasn't till I went home and had a look under the bonnet of my bb4 that I realised I didn't have the electric vaccum solenoid in line..

So recently I managed to find it at home but every time I plug it in the cooling fan comes on when I switch the ignition off, unplug it and it goes off ... and it doesn't make any difference to how it drives..

Anyone else had this or know what's going on?

[Scott560]

I'm not a 4th gen expert, but the fuel pressure regulator shouldn't have any interference, just a pure vacuum feed from the manifold (so that the FPR can maintain a constant pressure differential to the inlet pressure).

any unused vacuum solenoids are almost certainly for something else (evap canister purge, resonator, dual length runner flaps etc).

If plugging in a spare connector makes the fans come on, then its likely the connector is probably for a temp sensor of some description. a lot of honda 2 pin sensors all have the same connector, and given there are so many on the loom, its not that difficult to get them misplaced (i had the fortune of rebuilding a b16a2 recently and putting the loom back on was a a bit of a guessing game in this respect).

[wurlycorner]

So recently I managed to find it at home but every time I plug it in the cooling fan comes on when I switch the ignition off, unplug it and it goes off ... and it doesn't make any difference to how it drives..

Anyone else had this or know what's going on?

No idea why the fuel pressure regulator should make any difference on that at all but... Are you sure that's not how it's meant to work?
Not sure, but there may be a timer on AUDM ludes that is meant to turn the cooling fan on for a while after the engine is switched off?
Have you tried leaving it running for a while and seeing if it does then cut out? (maybe 5-10 mins?)

[JEBB4]

I'm not a 4th gen expert, but the fuel pressure regulator shouldn't have any interference, just a pure vacuum feed from the manifold (so that the FPR can maintain a constant pressure differential to the inlet pressure).

any unused vacuum solenoids are almost certainly for something else (evap canister purge, resonator, dual length runner flaps etc).

If plugging in a spare connector makes the fans come on, then its likely the connector is probably for a temp sensor of some description. a lot of honda 2 pin sensors all have the same connector, and given there are so many on the loom, its not that difficult to get them misplaced (i had the fortune of rebuilding a b16a2 recently and putting the loom back on was a a bit of a guessing game in this respect).

Cheers for the response, the solenoid is 100% supposed to be there, it even has its own little bracket that bolts to the rail that the loom clips into, my bb4 had it and ran spot on and never had this issue, the plug for it is in the same section of loom that the injector plugs and egr plug is so it has no chance of reaching any coolant sensors..

I'm thinking you could be onto something with it being audm specific thing with the interior loom wurleycorner
Or maybe I've made a connection I shouldn't have when wiring in vtec... it doesn't cut the fan in when running from what I can tell but comes on when ignition is switched off but then stays on until battery is flat..

[Scott560]

the only other connector in that area could be intake runner 1 inlet air temperature sensor (white plug usually)?

If the loom is expecting an air temperature sensor - and you plug it into a solenoid (dead short), it will think the inlet is roasting hot so perhaps that explains the fan (to reduce engine heatsoak after shutdown?)

If you've done an engine swap all bets are off as to anything lining up properly unless you have the old engine side by side to compare with.

The solenoid / vacuum feed - do you have a picture to show how its plumbed in?