Megasquirt TPS for S4
#2
(Terraplane)
I bought three of these just for back-up from here;
https://www.aliexpress.com/store/pro...000355952.html
Hard to be the price.
Also connector & boot.
Connector Kit for Throttle Position Sensor TPS | TPSCONNECTORKIT
Mounted it like this.
Second one works fine, although I did have one fail probably due to poor alignment.
https://www.aliexpress.com/store/pro...000355952.html
Hard to be the price.
Also connector & boot.
Connector Kit for Throttle Position Sensor TPS | TPSCONNECTORKIT
Mounted it like this.
Second one works fine, although I did have one fail probably due to poor alignment.
#4
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#5
Old [Sch|F]ool
I have never found a need for a full range TPS when I was running a stock intake manifold (GSL-SE, S4 N/A, S4 TII). Once the TPS is out of range, you don't really need more acceleration enrichment anyway. At lower RPM you will go to atmospheric in the manifold before the TPS is out, and at higher RPM you don't need acceleration enrichment because the main fueling is sufficient.
There's software in the code to disable accel enrichment over a certain percentage, Mazda just does it in hardware.
I do have a full range TPS on my Holley but that is more of a convenience than anything. It burps a bit rich on throttle opening at high RPM, but only just a bit, at that point the enrichment is a drop in the bucket.
The only advantage to a full range TPS is that the Mazda TPS relies on internal spring tension to follow the throttle plate, and when they get dirty internally, they sometimes stick. Then you get no acceleration enrichment until a second or two after you move the throttle, resulting in a lean hiccup when you move the throttle followed by a bog a few seconds after. Easily diagnosed if you still have functional LEDs on the case and the case is visible while driving.
There's software in the code to disable accel enrichment over a certain percentage, Mazda just does it in hardware.
I do have a full range TPS on my Holley but that is more of a convenience than anything. It burps a bit rich on throttle opening at high RPM, but only just a bit, at that point the enrichment is a drop in the bucket.
The only advantage to a full range TPS is that the Mazda TPS relies on internal spring tension to follow the throttle plate, and when they get dirty internally, they sometimes stick. Then you get no acceleration enrichment until a second or two after you move the throttle, resulting in a lean hiccup when you move the throttle followed by a bog a few seconds after. Easily diagnosed if you still have functional LEDs on the case and the case is visible while driving.
Last edited by peejay; 06-12-17 at 05:55 PM.
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#8
Engine, Not Motor
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As others have mentioned, it's really not necessary. Tuned loads of S4s with the 1/4 range TPS and for a basic setup it works just fine. The only quirks is that if you use TPS to determine open/closed loop you may knock yourself out of closed loop at lower than expected throttles, it's not great for throttle based boost control, data logging shows 100% throttle long before, must keep in mind the 1/4 when tuning accell pump, etc.
#9
Senior Member
Running the stock s4 tps on my setup, realistically I see no issue with it. Sure it shows WOT sooner, but at that point your really looking at your fuel table anyways.