Hi.

I'm in the beginning stages of converting my 1971 1.7L D-jet injection system to a Megasquirt system. Today I welded in an oxygen sensor bung into the collector of my Bursch exhaust. I also ran past the junk yard to find a TPS, which I've heard whispered from other members that some Nissan TPS units are a good replacement.

I have two questions:

(1) Is this the right one? I pulled it from a 1990 Sentra.

(2) Do I need to wait before I get all Megasquirty with the rest of the installation, or is it electrically possible to install this now with the existing D-Jet? I ask because my current TPS is shot, despite my attempts to clean it up. These early TPS units don't have any newer replacements.

Thanks for reading.

-marcus

marcus,

from what i understood the stock tps only has a few postions (i.e.: WOT, mid, idle) - i don't know the exact terminology for it.

the nissan tps should have a variable potentiometer installed, which will give the ECU a variable resistance reading.

I don’t think the nissan TPS will with the stock Bosch unit.

dragan
ps: I’m in the process to do the same upgrade. are you going with MS1/MS2 or even MS3?

It will for sure not work. Yes, all modern TPS are just potentiometers. I used a GM one, they work fine and are cheap new. I will tell you if you do the wrecking yard part finds, make sure you get the model and year off the car to make future replacements easy. You can run the megasquirt without a TPS, just set it for MAP for accel. I'm running the MS2 v3. The vote on the MS3 right now is over complicated, and lots of features we won't use on most 914 installs.

I got the idea in my head that I would need such a device based on searching this forum and gleaning what others have done in their Megasquirt installations:

http://www.914world.com/bbs2/index.php?sho...issan++throttle

http://www.914world.com/bbs2/index.php?sho...p;hl=98+hyundai

I'm going for (I think) the MSII v.3 unless I'm able to try one of JamesM's clever MS circuit boards. I plan to take many photos and start a thread.

-marcus

Hey guys,, he's using MegaSquirt FI,,, not a stock type ECU.

As far as the TPS,, I don't think the one you have pictured will work because you don't have a hole for the D shaped throttle shaft. I know it can be found,, but I'm not sure which import TPS to get. You will probably have to make an adapter plate which you mount your TPS,, then mount that to the stock throttle body.

McMark makes a nice sensor mount that will work with a 36-1 wheel for your ignition,, http://www.914world.com/bbs2/index.php?sho...;hl=tooth+wheel

I wish you luck on your project.

-Robert

Sorry, meant to say it will not work on the Djet per his question. Nice thing about MS, you can use pretty much anything if you can get it to fit.

Thank you all for the responses.

While I don't have a Megasquirt system just yet, I've already begun some of the work necessary to begin the conversion. In the next day or so I'll start a thread and begin posting photos to detail my progress.

Of the ten thousand questions I'll have to answer is whether or not to use a TPS. I know that you can get away without having to use it, but I've heard it said (which may or may not be worthless) that its a little easier just to use one. I'll find out and report back.

More soon.

Huh.

It's easier not to use one. On a stockish motor I don't think it makes much difference either way. I think the acceleration is just a little snappier with it, but that may or may not be real. Every TPS i looked at required adapters to be machined to make it fit on the stock TB, I even cut the shaft down on my TB to make it fit properly without a ton of spacers.

I'm of the thinking that to only use a map means you have already opened the throttle for awhile before the engine can take in the air and the motor will be more laggy on aceleration without the tps. I'm lucky I got a two barrel intake for a t4 that I will put the whole throttle body on from a later gm motor. I will probably use a 2.8 tb as I have a few of those on hand.