# MR2 PS pump



## e_canuck (May 8, 2008)

Hi.

Congrat. I know the feeling. Did yours come with the connectors attached?

I had to make my own, so I could test the darn thing.

















It whirr so smootly and as advertised it then power down one notch. A beauty.

If you are looking for the schematics go to the wiki.
http://www.diyelectriccar.com/forums/showthread.php?t=19505

Thanks again Dimitri.

take care,

DP


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## PatricioIN (Jun 13, 2008)

no, it was removed already when I got there or else I would have asked for the connectors and the pressure line... Plus, the guy was about as friendly as a wet cat, so... I took my $100 pump and was happy to leave! lol


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## e_canuck (May 8, 2008)

Mine looked just about like that when it got here. The fluid leaked out, covered it and soaked the box. The UPS guy must have been happy. It also came covered with Kentucky red soil.

It cleaned really well with engine degreaser and water.

DP


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## PatricioIN (Jun 13, 2008)

hey, this may have been asked/done already.. but couldn't you run a dash switch to the power line for this and turn it on/off when you wanted PS?


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## ISellMiataParts (Sep 24, 2008)

PatricioIN said:


> hey, this may have been asked/done already.. but couldn't you run a dash switch to the power line for this and turn it on/off when you wanted PS?


better yet, hook it into the speedo so it only clicks on when the car's speed is below 10mph...


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## PatricioIN (Jun 13, 2008)

ISellMiataParts said:


> better yet, hook it into the speedo so it only clicks on when the car's speed is below 10mph...


lol.. that'd be great.. but perhaps a bit beyond my know how! Hell, I'm not even sure if the '98 ZX2 I have is a mechanical or electronic speedo.. I have the factory manual out in the garage, so I can check that out..

edit: hmm, apparently (according to teamzx2 forum) it does have a VSS.. and I know from dmitri's schematic of the mr2 ps pump, there is a connector for VSS.. hmmm..

Ok, anyone know how I would determine if/how they work together?


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## dimitri (May 16, 2008)

> Ok, anyone know how I would determine if/how they work together?


I would put the car on jack stands, wire VSS to the pump, put car in gear and "drive" so the wheels spin and tranny produces VSS signal, hook up ammeter in the pump's power circuit and see if it drops to zero when your speed picks up. It should trip the relay at certain speed, then trip it back as you slow down.

NOTE: This is all purely theoretical speculation based on my research, I have not done VSS hookup because Miata has a strange VSS wiring which I haven't figured out yet.


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## ISellMiataParts (Sep 24, 2008)

what is vss.


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## e_canuck (May 8, 2008)

Hi.

VSS means, i think, Vehicule Speed Sensor. Newer cars have data flowing to computers. For things like power steering, ABS, cruise control.

In this case if the VSS data is compatible, the pump would only work at low speeds. As determined desirable by the Toyota engineers.

DP


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## ISellMiataParts (Sep 24, 2008)

interesting, OBDII?


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## e_canuck (May 8, 2008)

Possibly. I am still learning this stuff. If the VSS signal goes bad you can loose speed indication, the car will not shift to a higher gear, the check engine light could come on.

My Sunfire seems to have two. They complement each other. If one goes bad you get different symptoms. I have no idea how to get a signal from them. Yet.

DP


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## e_canuck (May 8, 2008)

One last thing.
If I understand it right, it also feed into the car radio. That way the volume goes up with speed and decrease with speed.

So it might be possible to get the signal from the radio harness.

Comments from smart people are invited.

DP


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## ISellMiataParts (Sep 24, 2008)

Take it off the speedo signal on a miata. After 1994 I think the tach signal was electronic and you can measure the power fed through the speedo. 90-93 miatas use an analog tach where a wire is run from the tranny to the back of the gauge cluster. (i realize now im not sure how exactly the electronic signal gets to the cluster on a later Miata)

I have an aftermarket computer system in my race car for tylemetry (sp?), I have wired a lead to the back of the gauge cluster to pick up the tach signal, it's labeled like "TS" or something, it's a little brass screw. I just have a ring terminal around it. I'd be reasonably certain the same thing exists on the speedo.

Miata radios did not adjust for speed until the later 2005+ models (NC)

Those of you with NB Miatas (99-04), did you have to do anyything special to get a speedo signal?


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## PatricioIN (Jun 13, 2008)

e_canuck said:


> One last thing.
> 
> Comments from smart people are invited.
> 
> DP


lol... I'll just laugh since I'm not sure if I fall into that category..


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## dimitri (May 16, 2008)

My Miata is NB ( 2001 ) and I have complete set of electrical schematics. VSS signal comes from hall effect sensor in the tranny, Tach signal comes from the engine which now Rests In Peace. Tach is irrelevant for PS Pump, it needs VSS. The problem is that VSS sensor has 2 wires going directly into microcomputer inside of gauge cluster which drives speedometer and odometer, it does not ground one of these wires. VSS on PS pump assumes a ground connection to complete the circuit. This means I would have to ground one of VSS wires on Miata, which could kill my gauge cluster, and I am not even sure if pulse signal has correct voltage to drive PS pump input. Because of this I have not yet tried to connect VSS to the PS pump on Miata. 

On other cars if VSS signal is a single wire going to ECU and radio etc. its more likely to be standardized pulse and should be compatible with the PS pump, since its compatible with most radios I assume there is sort of a standard on pulse voltage, etc.


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## ISellMiataParts (Sep 24, 2008)

is it possible to adapt the MR2 feed to a miata tranny?


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## TelnetManta (Jun 5, 2008)

WOW, I just got my pump today and this thing is HUGE!!!! The yard I got mine from cut the high pressure line but left the fitting in the pump so at least I can have a hose made locally.

By the way, got mine for $65 shipped.....


Ben


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## PatricioIN (Jun 13, 2008)

ok.... so I've mounted and plumbed my pump.. attached the relay and made all the wires. All I have left to do is hook up the power wires and see if the wire to the VSS works.. 

One question. I still don't fully understand the difference in the wiring diagram from the wiki.. it shows 12v power from the ignition switch going in to the relay and to the pump.. AND it shows 12v 50amp power going in to the relay on a different tab.. 

What is the difference between the two?? If the ignition switch wire is from the "on" position, then were does the other 12v source come from?


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## elevatorguy (Jul 26, 2007)

PatricioIN said:


> ok.... so I've mounted and plumbed my pump.. attached the relay and made all the wires. All I have left to do is hook up the power wires and see if the wire to the VSS works..
> 
> One question. I still don't fully understand the difference in the wiring diagram from the wiki.. it shows 12v power from the ignition switch going in to the relay and to the pump.. AND it shows 12v 50amp power going in to the relay on a different tab..
> 
> What is the difference between the two?? If the ignition switch wire is from the "on" position, then were does the other 12v source come from?


I would source the other 12 volts from the battery through a suitable fuse.
If you ran that high current through the ignition switch it would make it fail quickly or just melt 
The relay is your high current contactor for your pump triggered by the ignition switch.


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## PatricioIN (Jun 13, 2008)

update: I hooked the 12v power to the relay from the battery pos as suggested and gave it a whirl... works great! No leaks. I don't know if my vss signal will work it properly or not, but it revs up when I turn the wheel and back down when I stop - just as it should. Plus, I put an on/off switch on the dash from the ignition run line so I can turn it off if/should I want to. I don't think I'll really need the PS except for parallel parking; I can turn the wheels easily enough with it off even now that it is fully loaded.


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## PatricioIN (Jun 13, 2008)

update:

have driven a few miles and would say using the PS is a definate. Much harder to turn wheels while turned off.. I leave it on now. Only seems to pull a few amps while "idling".


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