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NA mpfi EA82 just 2 wire TPS !

Posted: Tue Mar 11, 2014 5:16 pm
by steptoe
Yep, found I have an EA82 mpfi throttle body with just two wires in the loom. Suspect it was from my NA mpfi Touring Wagon. Were they this basic ? Two wires? That is all that was in the loom !!

Posted: Tue Mar 11, 2014 8:37 pm
by Gannon
Photos?

I had an 88 MPFI tourer and it had 2 plugs to the tps, one was for the throttle switch, the other for the potentiometer throttle position sensor

Posted: Tue Mar 11, 2014 11:16 pm
by RSR 555
Sounds like a throttle switch.. not a TPS

Posted: Thu Mar 13, 2014 12:19 am
by El_Freddo
I'm 99% sure all of my "series II (hotwire AFM)" MPFI systems have three wires.

Cheers

Bennie

Posted: Fri Mar 28, 2014 1:17 pm
by wagonist
I've seen 3, 4, & 5 wires, but never 2.

Series 1 TPS didn't have a potentiometer, just an idle & full throttle switch. So that's 2 wires, but there still should be a power wire to go with that.

The spider manifold engine I've got has a 4 pin plug, but is missing the TPS as it was wired up in an earlier Vortex. Now I'm trying to adapt my 5 pin TPS into that loom...

Posted: Fri Mar 28, 2014 9:58 pm
by steptoe
No pictures now, imageshack want to share my income. I'll have to find that two wire and report on wire colours

Posted: Thu Apr 24, 2014 10:41 am
by RSR 555
Don't you have a photobucket account now?

Posted: Thu Apr 24, 2014 8:10 pm
by steptoe
Yes, but that needle is now somewhere in the haystack. Hatstack just became an L Sedan worse this week. Body and all other L crap gone, jammed inside the 2 cubic meter garbage bin the body turned into :)

Not going anywhere are you ?

Have you been attending touch typing classses out there in no mans land ? Bloody lot o freplies by you tonight, so far!

Posted: Thu Apr 24, 2014 8:36 pm
by RSR 555
I've spent a whole day replying to posts due to not having access to AUSubaru for the last 29 days.. do you know how hard that is for me :evil:

Posted: Sat May 10, 2014 6:07 pm
by steptoe
While Paul is still in the house

Image

grey ringed injectors - has to be from the 89 mpfi NA Tourer. Only two wires out of the sleeve, only two connectors in the plug - room for a third though

Posted: Sun May 11, 2014 11:45 am
by RSR 555
Ok. I'd say it's a throttle switch as apposed to a throttle position switch. Grab a multimeter and test the switch first for resistance then for conductivity.

Posted: Sun Jun 01, 2014 9:10 am
by steptoe
found this discussion between Disco and another USMB member

The Spider TPS can be made to work with the Hotwire MAF system easily. Basically, both are potentiometer types with a Power, a signal, a ground and an idle switch that gets grounded at closed throttle. on the 3+3 type, if you look carefully, the plug that goes right onto the TPS only has 2 wires in it(so really it's 2 +3). It is the idle switch portion. One wire is ground, the other carrys the grounded signal back to the ECU to tell it that the throttle is closed. The 3 seperate wires are a gound, a power, and a signal form the potentiometer portion. To make this style work with a Spider TPS you just need to combine the 2 ground wires(or just cut ff one of them, since they are already combined further up the harness) and match the remaining 3 to their respective pins(power, signal, Idle) on the Spider TPS.

As far as using a Spider TPS with the older type, I can't see how it would work. The old style is not a potentiometer. It has an idle switch and a wide open throttle switch. the standard(non-spider) TPS from the newer type (3+3)has the same idle switch and may even have the WOT switch inside it as well(the unused pin) They seem to be a hybrid, almost as if they added the 3 wire pigtail as a retrofit. So it's possible that it would plug and play onto the old system.

But the spider ones are totally different and have no WOT switch. It may run the older style to an extent, but you will never get WOT signal so may run lean under full throttle. On the old style when the idle switch is off, but the WOT switch hasn't been activated, the computer uses the MAF and the O2 sensor to determine fuel mixture.

I also have one of those alleged 3+3 TPS somewhere, must look next time I get a cave in - study items more closely as I dig self out :p

Posted: Sun Jun 01, 2014 6:25 pm
by Gannon
Spider TPS is quite like the EJ TPS

Adrian I believe adapted the older type throttle body on the spider manifold and mounted it upside down so the throttle cable pulled the right way.

Posted: Sun Jun 01, 2014 10:40 pm
by steptoe
He did indeed - had a plate welded on manifold to bolt 3 plug ECU throttle body to, smae size throttle plate

Posted: Mon Jun 02, 2014 5:21 am
by RSR 555
I would say this 2 wire is off a 1986 Vortex because these used the early EFI system and from memory anything after 1987 was completely different. Easiest way to spot the difference was the Air Flow Meter. Unfortunately I no longer have my EA82 EFI from my 89 L.Series to check the wiring for you but I suspect mine would have had 3 wires.

The grey injectors I'm not sure about Jonno. This is only on the EJ series. I'm 99% sure all the EA injectors were the same.

Can I ask what you are trying to achieve? this might be better to help you with an answer ;)

Posted: Mon Jun 02, 2014 8:33 am
by steptoe
achieve ?? Probably a bit more head space not thinking about why I thoughtit'd have three wires, then spied just two wires - al about trivia sharing :)

1% room for error. If I take a pic of red and grey injectors from EA NA and T, side by side - we might all remember a little better :p :D - waste a little more head space for anyone who looks !

Think you might be right about early Vortex. Have seen one, mpfi and it had a dizzy with, sure it was the twin ports on its vacuum canister ??
And yer wrong about it bing off a Vortex of any kind - came off 89 mpfi NA TW when I pulled it

Posted: Mon Jun 02, 2014 8:58 am
by Subydoug
My 86 MFPI has three wires. One common, One is closed at idle and the other is closed at about half throttle. Maybe subaru Got creative and used the single switch for both positions. Opens just off throttle and closes again at half stick.

Doug

Posted: Mon Jun 02, 2014 8:03 pm
by RSR 555
Ok, so maybe it's the other way round. I don't have mine to check against anymore. I have my Tex but she's probably in 3 foot of grass right now :(