Question for he who bought Cruzingbrumby's EA82T engine .

discopotato03 · Post by **discopotato03** » Thu Jul 03, 2008 6:31 pm

I remember looking at this engine ages ago and noted it was an import one and had a different cold start air bypass valve ie not the weirdo thermostat housing type . I seem to remember it having the type used on the spider inlet manifold and 101 Nissans from that era .

I'm thoroughly fed up with the thermo housing type and want to use the other type only I can't figgure out where it went - towards the back of the inlet manifolds water log - I think . Fingers crossed if I'm right all MPFI engines can have the better (more easily replaced) valve if need be .

Why would I want to do this ?

Firstly thermostat would be a doddle to change (which I do summer and winter) .

Secondly , I HATE engines that idle faster than they need to when warming up because it makes life difficult for the gearboxes syncromesh .
The methods used to make dinosaur engines of the middle 80's era idle when cold continue to feed air into the engine even when the throttle is open meaning a lazy return to an elevated idle speed between gear changes - until the #@^* valve closes up fully .
Short of paying stupid money for a new std one I prefer the alternative type and they are available in different sizes .

Cheers A .

Gannon · Post by **Gannon** » Thu Jul 03, 2008 9:03 pm

I know the XT6 used a different one to the rest of the EA82's that operated like many modern cars, where the ECU can control it infinitely by varying the voltage/duty cycle to it. There was no FICD for aircon as it was all controlled by this device.

As for the JDM spider manifold EA82, i believe it still just used a heater to gradually reduce idle speed over a few minutes. I have a feeling the device was called "rotary vane' something. I have an 88 XT FSM somewhere here, i'll have a look for you.

Gannon · Post by **Gannon** » Thu Jul 03, 2008 9:54 pm

Found em... just have to upload them somehow

Basically, the XT6 uses a 'By-pass Air Control Valve' which with the ECU, operates as a closed loop idle control. As to what controls it, im not sure whether its a 'variable duty cycle' or a 'servo type' control.

The XT4 (im refering to the EA82 with the spider manifold) uses a 'Auxiliary Air Valve' that contains a coiled bi-metal shutter valve, that reduces idle speed as the coil heats up.

The ones on our normal EA82 MPFI/Turbo engines use a coiled heater as well as heat from the thermostat housing to operate the shutter.

steptoe · Post by **steptoe** » Fri Jul 04, 2008 10:14 am

second time in an hour I've written " a pic speaks a thousand words" or to that effect

This is a pic I took just now of the EA82T's thermostat housing of engine I bought from Adam on 27 August 2007. It looks no different to others I have seen.

You want the type seen on Spider manifolds look like Volvo part ?

Dunno how many Adam had, but it wasn't this one with the system you want

Gannon · Post by **Gannon** » Fri Jul 04, 2008 4:58 pm

Wanna start a picture comp ay?

Here are some scans of the XT/XT6 manual showing the air valve for both motors

Adrian.. if you wanted one for your EA82T, id suggest you go the Auxiliary air valve from the XT4 motor, as the By-pass air valve from the XT6 needs a special signal from the ECU to constantly adjust it. Im searching the manual for info on that signal

discopotato03 · Post by **discopotato03** » Fri Jul 04, 2008 8:06 pm

LOL , thanks guys . I have 3 spiders in the cave and the XT4/6 manwell as well .

Must be slipping , I was sure that import EA82T had the other air valve style .

No probs , can make a small ally plate to fit the other type valve and the thermo housing .

Cheers and thanks , A .

steptoe · Post by **steptoe** » Sun Jul 06, 2008 11:06 am

I woulda been upset if it did have that other style...only because it reminds me of old Volvo