E30 Zone

Just wondering if there is any disadvantage in relation to cold starts when using megasquirt. Also how much roughly to install in a 325i with wasted spark. Cheers

Hi sk712. Firstly I better qualify that I'm not a megasquirt user, or an m20 owner but I am in the process of building megasquirt for my m42.

Are your cold start questions related to what you've heard about MAF conversions? I believe these are inherent to mapping rather than changing the that management system so I'm confident the answer to you cold start question would be. No, not if it's mapped properly.

I think said MAF issues were related to intake air temp and as MS will require either a new sensor or calibrating to whatever sensor you have I doubt it will be a problem. I stand to be correct here but that's my feeling.

Cost would depend on how you went about it. Fully fitted and mapped might be in the order of 500quid? If you build and fit yourself you can give to somebody to tune who know and that might be cheaper and easier than buying RR/wideband sensor to tune yourself.

With mine (2.7 M20 on megasquirt with wasted spark) the only issue or noticeable downside to the MS is cold starts. Basically when I go to start it in the morning the following happens:
- It will fire up and run, then die straight away. (this may happen again but usually once)
- Fire it up again and when it starts I need to give it a bit of throttle for about 2 minutes before it will idle decently.
- Then your ready to go
- After that the next time I need to start, it it will start normally. Even when its sat and got cold again. I only need to do the above when its been sitting over night.

I'm not sure if this is how it should be but I havent had a chance to go back and speak to Ant about it. But I think its normal?

^ but then again I have no ICV

You could probably use a solenoid to open the throttle during cold starts.

surely its just a matter of adjusting of fuel delivery vs temp compensation..........however this is specifically done with MS. Also the ICV can be helpful.

http://www.e30tech.com/forum/showthread.php?t=45774

Hadrian wrote:You could probably use a solenoid to open the throttle during cold starts.

Thats what I was thinking. Would be good to have a set up that when I started it from cold a solenoid could be used to open the throttle for 2mins and warm the car up for me while I have a cuppa

an ICV will cure the cold start idle pullup issue, Oakey doesn't have one fitted as he's moving to ITB in the very near future.

you can use an ICV with MS, set the frequency to 100HZ and warm idle to 0% cold idle to 100% and the PWM will sort the rest out( obv a few boxes to fill in but thats it in a nutshell)

or use a waxstat or LE jet style ICV to sort the cold start out.

@ Dave, you got them TB's yet dude ??

No There coming along though. I'll pm him and see if he's got any updates