Welcome to IsuzuPiazza.com :: Uniting Isuzu/ Holden Piazza Enthusiasts since 2002

i pulled apart the TB & plenum stuffs today and found this sensor just laying about on top of the #1 runner or so, kinda beneath the fuel rail & first 2 injectors:




it was still plugged in but the bracket was not mounted to anything & it was just sitting there in no particular special way.

I am familiar with the gauge sender & ECU sensor just like my 4ZE1. from browsing my JR repair manual in the past I recall seeing 3 temp sensors for the 4ZC1-T? 3rd one as for direct feed to the TCS.. i cannot find it in the book now


is this correct?

where is this thing supposed to be mounted?

Could be the sensor for the injector blower im thinking.

I think it just bolts on the top of the rocker cover to the left of the oil filler.

Bob.

Yeah that's the one Bob

ah, I recently removed the blower assembly and put it in the junk bin along with the cruise control actuator. I guess I'll toss the sensor in as well.

thanks

Probably a good idea to bin it, its as ugly as and sticks out like dogs balls.

Why bin the cruzzzzzzzzzzze?????


Bob.

ugly as and sticks out like dogs balls.

there was vac feed to the blower correct? there's a line that goes to where it was and I think I remember it. i'll have go dig out the parts & check for stub I guess. but this hose connects to a molded plastic pipe that snakes under the plenum and then wraps around to the front of the lower manifold. I was tracing this when I found the sensor sitting there.

but where does that hose pull from? is there a stub underneath the manifold?

there is so much freaking crap under hood, trying to get rid of everything not directly related to making the motor go vroom or for passing emissions.

Why bin the cruzzzzzzzzzzze?????

because I'd have to take my foot off the gas to let it do its job. once this little beast is up & running I plan on having my foot to the floor at every available moment.

turns out what I thought was a vac line really was for recirculation back to the blower.

here's the entire system:



^^that's up against the base of the t-stat/water inlet near front of the fuel rail, was fastened with a small screw. both of the curved ends are open & the hose attaches underneath and goes back to the fan.

it is odd that a fair amount of thought was put into designing something that wasn't really necessary.

Id say if you lived near the southern warmer states you could find out just how nessacary it is for the job it does.

Cheers. Bob.

i'm going to be residing in the hottest region of this country.

and i understand theoretically it can be helpful, but have other EFI motors come factory with something like this? i have never seen one nor any performance motors built utilizing such a system.

i suppose if crawling in rush hour traffic on a regular basis it would be prudent. please keep in mind I'm not trying to be an ignorant ass, just never seen anything like this and naturally must question it's ultimate necessity.

Impulsive Yank wrote:naturally must question it's ultimate necessity.

Im with ya on that. But hey it was there. Im not saying you should keep it, do as you please. Looking at the Piazza design and all the crap under the hood i could understand limited air flow over the inlet manifold.

But then i tought that blower only worked when the key was switched off.


BOb.

Impulsive Yank wrote:have other EFI motors come factory with something like this? i have never seen one nor any performance motors built utilizing such a system.

Mid '80s Nissan Maximas had those fans on their intakes. Not neccisarily a "perfromance application".


Madcat

But then i tought that blower only worked when the key was switched off.

That is my understanding as well, from what i have been told, when you switch off the engine there can be an extreme temperature rise in the area of the inlet manifold and because the injectors and rails are so close to the heat source with very little air circulation you can experience vapour lock essentially affecting fuel pressure and causing hard hot restart. The system as I understand it is thermostatically contolled and the blowerr activates when the engine is switched off and stays on until the temperature drops sufficiently in that region. I have not found out if there is a time limit that over rides this or not. I have never heard of them coming on when the engine is running but then we don't need them here as the ambient is rarely above 30 deg C in Summer.

I think I posted this somewhere else but here are the conditions it operates under