Jump to content
HybridZ

Finally starting my MegaSquirt project!


S130Z

Recommended Posts

After waiting for some spare cash to buy MegaSquirt, I finally lucked out and sold my old stereo system. I posted it on craigslist for $400 yesterday and I sold it today.

 

So here are my plans -

 

-I will purchase MegaSquirt II 3.0 as soon as the money clears into my bank account which will be tomorrow. My birthday is at the end of the month so I will buy a Wideband O2 once I get the cash for that.

 

-Purchase all the nick knacks for it like IAT sensor, wiring harness, stim, and tuning cable. I also need new injector plugs.

 

-I need to lock out my timing so I can control it via MSII.

 

-Replace my head gasket since I am pulling coolant through at idle from my number 3 cylinder.

 

-Swap out my 240sx TB with one that has a trigger style TPS.

 

Here is my setup -

 

-1983 Datsun 280zx w/ 190k on the motor.

-N42 intake manifold with 60mm TB.

-300zx fuel injectors, I believe they are 220cc.

-MSA 6-2-1 header running open 2.5" exhaust.

 

 

What I want -

 

I want to have the car in driving condition at least 24 hours after MSII install. This is my DD so I want a good drivable tune.

 

 

I am feeling a little stressed about the whole project considering that I have never built an ECU before. Any words to calm me down about this?

 

I will keep all of my updates posted as I go. Any thing missing here?

Link to comment
Share on other sites

You can get the sensors, including TPS, from a junk yard. I used the stock CHTS as the coolant sensor. I chose a GM air sensor. My TPS came from a Quest mini van, and I only had to build a bracket for it.

 

If you can solder, you can build the kit. Just take your time. I did mine in about 12-14 hours IIRC. The stim will help you test as you go. As far as getting a tune in 24 hours - some probably can, but I didn't. Maybe I'm a pessimist, but perhaps wait till a Friday to start so you'll have a weekend to fix any "gotcha"s.

Link to comment
Share on other sites

I have soldered some in the past, it seems pretty straight forward. I do plan on tuning over a weekend just to be safe. How long did the wiring harness take you? I have been told to find a base tune from someone else to work off of so I am hunting one down that is as close to my specs as possible. I have all the sensors besides IAT so I should be good to go with that. In the mean time I am reading my eyes off to get familiar with the system.

Link to comment
Share on other sites

Stock relay board? We don't really have one. You need a main relay and a fuel pump relay. You can harvest those from the junk yard too, from pretty much any car. Grab a handful so you've got spares. I used spade connectors crimped on to the wire, and for the fuel pump I ran new wires under the carpet. I used spade connectors to slip over the prongs for the pump itself. I didn't have to make any cuts.

Link to comment
Share on other sites

I just put MSII V3 on my L28E, a few things I would have done differently:

 

-not use the MS relay board. I would have made my own little fuse/relay board that only connected the wires it needed, and not every single wire that goes to the engine

 

-Used injector resistors and ran them as high-impedence. The PWM circuit cause a ton of really hard to track down noise. Putting in the resistors fixed this.

 

-Sharpie the whole contact on the distributor rotor, after you get the trigger offset right, make sure that the sharpie is worn away towards the middle of the contact, it its not, move the distributor and reset the trigger offset. I was getting a missfire if I went below 20 degress because it was firing off the edge of the contact.

 

Thats all I can think of now, you can PM me if you have any questions

Link to comment
Share on other sites

Flexicoker, those are some great tips. Especially the last one. You should add them to one of the stickies, such as the overview/newbie thread.

 

I've also seen that running a separate power/ground for the PWM circuits helps with the noise.

 

S130Z - I'd recommend fixing the head gasket first and making sure the car runs good on the OEM system. Trying to track down engine issues while installing a new system on your car is crummy.

 

Invest in a really good soldering iron. You don't need a soldering station, but a good 30W iron will make life easier. A magnifying glass, or better yet one of the weighted thingies with alligator clips and a magnifying glass that adjust all sorts of ways helps a huge amount. Get a solder-sucker and solder wick too, makes messes easy to clean up. With the solder sucker it's super-easy to open up holes again when you de-solder and remove something.

 

My #1 most useful tool is a precision side-cut-off tool. It's just a little snipper thing, but with strong jaws small enough to get in between the pins on chips. Excelent for trimming leads in tight quarters.

 

-Eric

Link to comment
Share on other sites

These are all great tips! I will be changing the head gasket about a week in advance of installing MS. I am still feeling uneasy about the whole project as my knowledge is weak in this area. I am continuing to put in several hours a day in reading and home work to get the basics down. Luckily I have a friend with some tuning experience to help me out. I guess I just want to hear someone tell me it's a breeze and nothing to stress about.

 

Thanks for the advice!

Link to comment
Share on other sites

don't worry too much, I didn't know anything about wiring or soldering when I started. Just read a whole bunch, and make sure you've got a decent multi-meter. I recomend radio-shacks desoldering iron, its better than using a separate booger sucker bulb. Their soldering irons aren't that great though. I was really wishing for something stable to hold the board while I worked on it.

 

http://cableorganizer.com/

 

has some really cool stuff. The roundit side-entry stuff is great, and the braided PET is good for small clusters of 1-3 wires, its just hard to get over connectors.

Link to comment
Share on other sites

60/40 lead/tin rosin core solder. It's cheap, works great, has a nice low melting point, the fumes smell great and are good for you too. The silver stuff costs too much and has a higher melting point, making it a little harder to work with. The lead free stuff and the 'clear flux' stuff cost more than is needed. Something nice and thin, such as 0.030 is great. I've used a lot of radio shack part number 64-005 solder and like it. It's a nice sized spool, and under 6$.

 

I agree with flexi when he says the bubble operated solder-suckers are hard to use. I have a spring loaded one I really like, it was only five or six bucks. A good digital multimeter is an absolute must. Expect to spend at least 40$. Fluke makes some great meters, as did Metex. HP meters are good, but expensive and rare. It's not a bad idea to get to know a local electrics store too, not a radio shack, but a real one.

 

Wait, no, the lead fumes are bad, don't breathe them.

Link to comment
Share on other sites

The solder we use is a slightly different blend, 63/37 instead of 60/40, and it's pretty easy to use. I don't recommend the silver or lead free versions; they're often harder to work with. Built my first Megasquirt at home with a Radio Shack iron, but we use 60 watt Wellers at the shop and there's quite a difference.

Link to comment
Share on other sites

-Sharpie the whole contact on the distributor rotor, after you get the trigger offset right, make sure that the sharpie is worn away towards the middle of the contact, it its not, move the distributor and reset the trigger offset. I was getting a missfire if I went below 20 degress because it was firing off the edge of the contact.

 

I have never heard of that method before. That is a great idea on how to check the rotor phasing.

Link to comment
Share on other sites

If you have not soldered before or it has been a long time, take a 10 minute break every hour or so. Then go back a review what you have just done before proceeding. You may find a mistake or two along the way. This will help you down the road once you are trying to get it to work.

Don't hurry. Don't work if you are tired.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...