Exploring 3 plug TPS for Spider TB .

[discopotato03]

Hi all , am looking into a bolt on TPS for the spider TB so it can be run with the MPFI 3 plug (flap AFM) EFI system . I have found a Daihatsu Aplause one that turns the right way and has the right 3 wire EFI plug fitting . Fingers crossed it will bolt up or go close , its ID sticker mentions 12v and 1.5 60 .

I gather this means it runs 12v across its switches and 1.5 and 60 deg are the shaft degrees at which they open/close .

 

If it fits I'll post the part number on the sticker , its an ND part BTW .

Before I go can anyone tell me the shaft degrees that the garden variety 3 plug MPFI TB's TPS shows wide open throttle ?

 

Cheers Adrian .

[discopotato03]

Didn't fit unfortunately but close - in other words not impossible .

 

I did find that the Spider TPS is JECS and that rings the Nissan bell , I'll try to find out if R30 (L series or FJ20) use the same narrow hole centres JECS TPS and turn clockwise to open .

 

I guess if all else fails I can use an external microswitch to do the open throttle switch bit .

Caboobaroo if your listening do you have any suggestions other than the drill through the top and mount it on bushes idea ?

 

Cheers A .

[Gloyale]

The hole for the throttle shaft in the TPS goes all the way through. Pry off the plastic case, drill a hole big enough for the throttle shaft to come through. Drill holes on the mounting tabs a little narrower to match the spider intake TB bolt holes. Make spacer sleeves for the mounting bolts, and mount it "up side down"(plastic towards TB).

 

I haven't actually run a car like this but I mocked up the setup on the bench and it seemed like it would work well.

[discopotato03]

What I want to do is have it like the factory would have had they used the early twin switch type three wire TPS .

 

ATM it looks like either a Nissan CA20E or an L24E uses the JECS TPS that should bolt up and plug straight in . Its possible one off an L28E ie 280ZX may work as well .

 

One other thing thats occured to me is that will the 3 plug MPFI-T computer run the Spider type IAC valve ok , both L and Spider type are single wire so fingers crossed the signals are the same .

 

Cheers A .

[Gloyale]

Early 80s Jaguar XJS(type III) uses a very similar switch type TPS. May even be JECS, I can't recall. But IIRC it rotates the correct direction.

[daeron]

I didn't catch on that you were after a switch type TPS. Nissan used a switch type TPS thru the 83 280ZX, although the later model turbos MIGHT be potentiometer type, so be careful if the valve cover in the JY says TURBO on it. It should be a JECS component.

 

I can't imagine why, but something somewhere in the back of my mind is saying that the Z-car switch (and thus all the L-6's) MIGHT have four wires.... so get a picture if possible, if you need to I can pop the hood on my 280Z sometime and triple check.

[discopotato03]

Sorry late getting back on this . The TPS on Nissan motors were close as in they physically bolt up but the drama is that they turn through a greater number of degrees closed to WOT so their TPS's won't work over the Subaru's narrower range . Also they turn in the opposite direction so the tracks for the switches are the wrong way around .

 

Didn't know about the Jaguar one , do they physically bolt up ?

 

Lastly its possible to buy here through Jaycar a switch kit that switches on an adjustable voltage signal . Can be made to work off a rising or falling voltage and the hysteresis (difference between on/off) is adjustable too . If this was run off the spiders potentiometre it would work I'd think . Spider TPS already has the idle switch just no open throttle switch .

 

Thoughts ? Cheers Adrian .

[Gloyale]

 

Didn't know about the Jaguar one , do they physically bolt up ?

 

It' close sizewise, but the mounting holes are a bit wider, and the plug is similar, but with different notch pattern. Both issues could be solved with a drill and a razor/utility knife.

 

Lastly its possible to buy here through Jaycar a switch kit that switches on an adjustable voltage signal . Can be made to work off a rising or falling voltage and the hysteresis (difference between on/off) is adjustable too . If this was run off the spiders potentiometre it would work I'd think . Spider TPS already has the idle switch just no open throttle switch .

 

Thoughts ? Cheers Adrian .

 

I see what you're getting at.

 

Idle switch would stay as is

 

potentiometer fed to said device.

 

Set device to only close switch above 4-ish volts for WOT

 

 

I think it might work. Or I could mail you the 3 prong TPS I drilled out and flipped over. It' sitting in a baggy in my parts box.

[Caboobaroo]

Hmmm very interesting...

 

Anyways, I finally saw this and read it through. I still fail to see why people have issues with the spyder intake. I mean, I took one from a natually aspirated XT and made it work on my EA82T without any problems after I fine tuned the engine itself. I used the complete intake including the spyder TPS and wiring harness, added in the knock sensor since the NA MPFI didn't have it, made sure it was pinned correctly to the EA82T main harness and popped it together. Didn't have any issue with it... Maybe I was lucky?

 

The only problem I ever had was I kept smoking engines but thats a given. I was even running an atmospheric blow of valve and it didn't stumble or get any issues with that either.

[Gloyale]

Hmmm very interesting...

 

Anyways, I finally saw this and read it through. I still fail to see why people have issues with the spyder intake. I mean, I took one from a natually aspirated XT and made it work on my EA82T without any problems after I fine tuned the engine itself. I used the complete intake including the spyder TPS and wiring harness, added in the knock sensor since the NA MPFI didn't have it, made sure it was pinned correctly to the EA82T main harness and popped it together. Didn't have any issue with it... Maybe I was lucky?

 

 

 

Let me guess, you were swapping onto an 87+ EA82T, correct?

 

The problem here, is that he is trying to use it on an old style 85/86 ECU set up, flapper maf, seperate ignition module, and importantly for this discussion, idle switch/WOT switch type TPS. The stock spider TPS won't work as it is potentiometer style. No spiders where ever used with the old style so there is no stock solution.

[Caboobaroo]

Let me guess, you were swapping onto an 87+ EA82T, correct?

 

The problem here, is that he is trying to use it on an old style 85/86 ECU set up, flapper maf, seperate ignition module, and importantly for this discussion, idle switch/WOT switch type TPS. The stock spider TPS won't work as it is potentiometer style. No spiders where ever used with the old style so there is no stock solution.

 

Yup thats the motor I was running it on. I must have missed the fact that he was running the flapper door MAF setup instead of the newer hotwire MAF setup. I think I need to go to bed...:-p

[discopotato03]

Hi Caboobaru , no this red kangaroo isn't as mad as you think !

 

While I do have the whole loom/ecu/MAF/ign bits etc from the Spider Turbo Vortex I want to run it on the 3 plug system . Why ? Firstly I hate MAP sensing so aftermarket ECU's are out . Second the 3 plug computer is dummer than the hotwire 4 plug and use basically a stand alone ignition system - that can be interfeared with and made programmable with a late optical CAS and a Haltech Ign only ECU . The fuel side can be altered at will with larger injectors and a programmable interceptor . Actually I wonder it the MAF voltage could be bent to run a 3 plug ECU .

 

All food for thought .

 

Also BTW the 86 FSM shows the number of throttle shaft degrees the open throttle switch is supposed to close at too .

 

Pray to god that one day someone with greater than a PEA sized brain markets aftermarket ECU's that use hotwire sensors . MAP sensing is really THE pits .

 

Cheers A .

[daeron]

This is "thinking outside the box" and it is probably worth absolutely nothing.....

 

BUT.. We Z-car guys, who run the older L-series cars (I6) have found that we can lift the entire engine control system out of a Z31 (84-89 300ZX, VG30) and apparently it can be used (and more importantly, tuned to fit) running an L-series.. There is a program called NisTune that is used to tweak the parameters of the ECU. Not 100% on all the details, but I can research more if you are interested and get you some links. IIRC, the dizzy needs to be modded, and our flapper AFM and throttle position switch need to be replaced with a proper hotwire MAF and pot-style throttle position sensor.

 

What about doing something similar with the subaru? Obviously an EJ setup would be difficult because it uses distributorless ignition.. but might you be able to hack into say, some Nissan or Toyota 4 cylinder control system and figure it out? The basic functions of any engine computer are similar enough that the project, for one properly equipped and motivated, is certainly not impossible..

 

 

Like I said, its a crazy idea.. BUT you seemed motivated, and you seem like you *might* be knowledgable enough to pull something along those lines off. In the end, there's only one way to find out. IF you could figure some junkyard stock system that would run the EA82T more capably than the stock engine management, something tells me you would make ALOT of friends here

 

I'll stop wasting bandwidth with my crazy ideas now.. but I had to suggest it. I am all for pushing the envelope.. a friend of mine put it best once. "There's something attractive about being a trailblazer..."

[discopotato03]

I'd not heard of that on an old L series , over here people usually flick the L6 for an RB20/25DET or RB30E/ET . In fact since the L has EFI available as you know its half way there , it just needs programmable ignition timing like the early 3 plug EA82T .

 

Perhaps I should explain the whole scheme .

Firstly my Subie L RX turbo has the early system and I think its a fair bit of work to change it . Secondly the 3 plug system is pretty dumb and easy to fool with an interceptor to alter the flap AFMs output signal . Thirdly you can't use an interceptor to alter fueling without affecting ignition timing with the 4 plug MAF system .

The thing that makes the 3 plug system crude is the stand alone mechanical/manifold pressure system of varying ignition timing . The computer itself is pretty dumb because all it requires from the distributor is an RPM signal and its happy . Since it doesn't care what the actual ignition timing is the system is open to alterations without complications . Its not a difficult thing to lock the dizzy and fit a programmable count back style computer to it and set whatever timing is best suited for performance . So its possible to have adjustable fueling and ignition timing .

I don't quite know how smart the 4 plug OBD system is but its entirely possible that it may sense its input signals not being factory and start all the self protect (basically rich/retard) crap .

 

As for an alternative to the Subaru 4 plug system , possibly a Nissan

CA18DET one ? They probably use similar optical CAS and the early ones I think even a distributor rather than direct fire (coil on plug) . The trouble is you have to find similar sized injectors and a plug in programmable ECU such as maybe an Apexi Power FC .

I personally think its a lot of expense for people playing with budget cars .

 

Anyway for me ATM its just a TPS solution and it will start and run with the std electricals .

 

Cheers Adrian .

[daeron]

Thanks for that response.. You've taught me a little more about the older subaru system.

 

Well, whatever you get into, feel free to PM me for ideas/questions/discussion. Hybridizing and making things work together is something I rather enjoy myself.. I wish I could say I do it a lot and am great with it, but unfortunately it is more of an un-exercised "knack" right now.

 

 

sigh.. I wish it was so simple to "flick the L6 for an RB20/25DET or RB30E/ET" over here.... people here tell me I need to put a smallblock chevy in it, and my reflex to that is to punch them in the face... I CONTROL that reflex very well, but that sums it up best.

[discopotato03]

Don't be offended by the V8 prime mover brigade , its a cultural thing bred into superficial people who don't question anything .

 

We went through this back in 1991-2 when the Grp A R32 GTR's destroyed the RWD 5 litre V8 competition in the Australian Touring Car Championship and the yearly Bathurst race at Mount Panorama .

All the beer swilling bison brained knuckle dragers could do was boo and chant bull************ bull************ .

 

Theres no smaller prison than an unopen mind .

 

Cheers A .

[cobcob]

Don't be offended by the V8 prime mover brigade , its a cultural thing bred into superficial people who don't question anything .

 

We went through this back in 1991-2 when the Grp A R32 GTR's destroyed the RWD 5 litre V8 competition in the Australian Touring Car Championship and the yearly Bathurst race at Mount Panorama .

All the beer swilling bison brained knuckle dragers could do was boo and chant bull************ bull************ .

 

Theres no smaller prison than an unopen mind .

 

Cheers A .

Bathurst! Now we're talking racing!!

Ain't nothin like watching those Holden/Ford fanboys getting destroyed by something that "has no place on a race track" remember the Mini's back in the day? Those guys TORE THE PLACE UP!!

My Dad still lives in OZ and is driving my old VK Commodore for lack of a better vehicle budget and he's posted a LOT of questions on Commodore forums when he needs some advice. It's always the same "Wider tires, cut the springs, 3" exhaust and it'll be Fully sick maaate!!" Thank goodness for a forum like this!

[daeron]

 

Theres no smaller prison than an unopen mind .

 

 

If ever was spoken a truer word, I haven't heard it.

 

 

You guys like the same parts about raceday that I do... we should form a club or something