andygoesfast

iTrader: (2)

I am installing an ms on my 90 miata. I have everything figured out besides the wiring of the tps? i know you have a 5v ref and a sig wire but where on the sensor are they?
thanks andy

Joe Perez

iTrader: (8)

Two questions:

1- Is this a standalone or a parallel install?

2- Is this the stock 5-speed TPS (three wires), or did you transplant a four-wire analog TPS onto the car?

andygoesfast

iTrader: (2)

stand alone.
stock tps but i have a 99 tsp sitting in my room.

Joe Perez

iTrader: (8)

OK, then.

First off, the '99 TPS won't fit onto your 1.6 engine without some custom machine work. So we'll look at your stock TPS. Here's the original configuration:


The Black / Light Green wire is ground, and the Red and Light Green / White wires go to the ECU. Specifically, Red goes to the switch which is closed at idle, and Light Green / White goes to the WOT switch. Internally, the stock ECU had a pullup on both of these.

We only care about the idle switch. So, at the MS, take pin 26 (+5Vref) and connect it through a 1k resistor to the factory Red wire at 1N, and also to pin 22 of the MS, which is TPS in. In other words, build this:




When the throttle is open, the +5 pullup from 26 will cause the TPS input to go high. When the throttle closes, the closure to ground at 1N will pull pin 22 down to 0.



That said, you don't actually need the TPS for anything. An analog TPS can be nice, but it's far from a requirement.

andygoesfast

iTrader: (2)

Thanks for the info. Will a auto one give the correct reading? We also have a zex kit we trying to hook up. So the question is will a auto give the correct output for the zex and the ms

magnamx-5

iTrader: (7)

most kits run of a wot switch anyway. The auto tps will work for you though. My nos is boost and switch activated you might look into that.

zarish

iTrader: (2)

So, for a standalone MSPNP you really don't have to do any tps mods if you follow the steps that Joe has listed above? Will this help in the car not stalling with AC on and the car comes to a stop? My car idles and runs fine, the only time I stall is when the AC is running and soon as I start to slow down and come to stop the can sometimes stalls.

Joe Perez

iTrader: (8)

With MSPNP, the tps is already handled for you. And no, it won't have any effect on stalling with the A/C, for that, check out the Great A/C FAQ: https://www.miataturbo.net/forum/sho...d.php?p=256739

zarish

iTrader: (2)

So if I follow what you have posted in this link then the A/C problem should be solved? I didn't really find anyone's post showing that it worked. I will give it a try and see what happens.\

I already tried messing around with the Idle control settings you mentioned in this thread, but still was stalling.

Joe Perez

iTrader: (8)

Yeah, that's because people are lazy ********.

Well, I hope it's the reason. Honestly, I have no idea if it will fix it or not. I don't have A/C so I can't actually test these theories. However I suspect that if you do the solenoid mod and also make sure that your "minimum" idle value is as high as possible without compromising warm idle (with A/C off), then you should see some results.

magnamx-5

iTrader: (7)

heck i have no tps and no idle mods and i can idle with ac fine is easy dude.

zarish

iTrader: (2)

You had have made some changes somewhere? My car will idle fine, even with the A/C. Its just when slowing down to a stop with A/C running the idle tends to drop without even noticing it. With the idle setting increased a bit as Joe suggested the car's idles between 1,000RPM - 1100RPM range I think. I will try it again today see what happens, will also see if the the mod will work. Magna you running an MSPNP? I am running MSPNSP9093.

zarish

iTrader: (2)

OK, not sure if I am supposed to mess around with the wiring with a MSPNP unit, but I did try remove the hose between the purge valve and the canister. I also tried changing spark and fuel settings it seems a little better but I can still get the car to stall. I also messed around with the dash pot settings but not successful yet.

zarish

iTrader: (2)

Ok, the only thing that seems to be working pretty well without stall and idle issues is changing the minimum idle d/c to 22 and advancing the spark and fuel a little. I drove around today with the A/C running. When coming to a stop as soon as you disengage the clutch the idle rmp's drop almost all the way down but seems to come up slowly. It feels like it will stall but on the last drive it didn't stall. Sometimes while coming to a stop the idle will hit about 1100 rpm and hold at this point it feels normal. I think if you mess around a bit with the fuel and spark settings the fix might be there. I will keep testing this.

Joe Perez

iTrader: (8)

Merely removing that hose will accomplish nothing, as the valve is normally closed, and the MSPNP never opens it. You need to make the bridge between the yellow / red wire at 2X and the green / black wire at 1Q. No mods to the MS.

If you wanna do a quick experiment, warm up the engine, remove the hose between the valve and the intake manifold, and try running the A/C. Your idle may be a bit screwy, but it'll simulate the effect of having the electrical connection made to open the solenoid when the A/C is on.

zarish

iTrader: (2)

It fukin started raining outside now, not sure if I will be able to try this right now, but I will try maybe tomorrow after work. Will let you know how it goes.

Joe I'm not good with wiring ****, where are these wires that you have listed above? Are they at the valve connection, or at the harness? Sorry for being so stupid about this.