No, don't go to the trouble of tracing your harness. I can figure it out. I mean hell, it's a 50/50 right? :-)

I have been conservative on the megasquirt because the directions warn that it's very easy to overestimate the cranking values and flood the engine. I don't want to fall into that trap where you start tuning in the wrong direction because you started out on the wrong side of the line to begin with but you don't know it (if that makes sense...lol). There is a newer version of the firmware that allows you set the cranking pulses for individual temperatures instead of interpolating between two endpoints. I'm trying to get that new firmware because that would give me a lot more control than I have now.

I realize that you are worried about flooding the engine during cranking, but think you've unnecessary scared your self a bit. There are lots of people on MS forums that have done this swap and can provide you with base maps for Normally Aspirated L28's cammed L28's, Strokers  and Turbo . They also have a ton of support on their forums.

Really, if you have Megasquirt, why would you even consider using the Thermotime switch and Cold Start injector? They are an archaic design with no tunabilty. And they really only come into play at fairly cool temperatures. A lot of guys in Southern state physically remove the complete CSI and Thermotime switch with Stock ECU's, as it's troublesome and not really needed in warm climates

With the MS you can provide full start enrichment very accurately through the main injectors. You just start off with low values and work your way up.  I'm going to be installing a Haltech system on my 1976 280Z this spring, and I can't wait to get rid of the archaic systems that Datsun uses, such as the CSV,TTS and AAR. They worked " OK " in there day, for what they were. But full digital and programmable control is the only way to go IMHO.

 

BTW, and excellant book for installing and tuning DIY Fuel Injection systems is " Performance Fuel Injection Systems " by HP Books. ISBN 978-1-55788-557-9 . Authors Matt Cramer  and Jerry Hoffman, both from Megasquirt

This book walks you step by step on how to set up stand alone EFI systems. It's purpose is to take some of  the " anxiety factor " many DIY's have when entering the world of Electronic Fuel Injection. And it does that in plain English with easy to understand explanations and step by step instructions that the layman can understand. It is a Gold Mine of information. 

 

 

 

 

Edited January 12, 20169 yr by Chickenman

Yeah, you're probably right about me being too careful. And I am only thinking about this as a last resort. I need to load this newer firmware because I know it will make setting the cranking pw a lot easier.

11 hours ago, Adam78 said:

I mean hell, it's a 50/50 right?

Haha! Yes, it's 50/50, but don't go simply guessing to see if it works or not. If you get it wrong, you will short your "hot in start" signal straight to ground through the thermotime switch and burn something up. At least put a meter on it first and see what the resistance readings are to the case.

I built a small relay contraption for my water temp sensor that would fool my stock ECU into thinking the engine was way cold when my key was in START. Provided the extra fuel boost to start the engine. I took it off this past summer when it was hot though.

Oh, I know. I was just joking. Hopefully I can just figure this MS out and not have to mess with it at all. We'll see.