Ok had a Megasquirt system installed on the 3.0. Much better throttle response and looks oh so sexy. Tuning was something else but it runs pretty well. Two issues:
1. After a cold start, the car is not drivable for at least two minutes, until it warms up. If you try to drive it cold it just stalls. Is this normal behavior?
2. The throttle is a tad touchy. Unless you slowly squeeze the throttle accelerating is like an on/off switch, with a millisecond of hesitation and then off we go. Is that normal or can that be tuned out?

My old 3.0 with megasquirt ran well even cold.. Did you enrich the cold start cycle.

So I'm hardly and expert (been running it on a 2.3 for about 4 weeks now), but I do grapple with the cold start idling issues. I've got no issues with throttle response, however.

So I wouldn't think it's a Megasquirt issue, because that's got so much flexibility in tuning. Your issue is either the tune and/or the components used in the build aren't sized or configured properly. Ben's right - you have a lot of capability to enrichen during start and warm up as needed. You probably knew that, but it takes a fair amount of time to fiddle with it as you only get one "real" cold start per day to test changes.

In my cold idling issue I'm thinking the IAC may just not be big enough to let in the air this engine wants when cold even when fully open. I believe it's a Kia IAC, and at some point I may look for something bigger if I can't get figure it out through tuning.

http://thedubshop.com/contact-us/

For the on/off issue, another thing to look at is the mechanical opening of the throttle plates. You want less movement at low throttle and more movement at higher throttle. Generally, at full throttle plate opening, you want the actuating mechanism at 90 degrees.

Short answer, yes. This isnt a deficiency of Megasquirt, this would be related to details the build or the tune, but cant really say without more information. What sort of induction are you running? Is an idle control valve being used? Has the warmup curve been tuned? What does the mixture look like while its warming up?




Again, need more information, its either the build or the tune. What induction is being used? Has the fuel map been dialed in, have accel enrichment been properly tuned? What does the timing look like? what does the cam look like?

Seeing datalogs would help as well.

The thing with megasquirt is you get out of it what you put into it. Just slapping parts on a motor doesn't guarantee it will work well, there is a quite a lot of proper planning and follow up tuning involved to maximize results.

Cold starts are fine but it has to warmup for two minutes before being drive able. Drive ability is great if I mash the throttle, no hesitation. But in normal around time driving, when I grab a new gear, I get that slight hesitation. I do have an intake air control for good cold starts, it’s just my impatience to get going after starting by not waiting 2 minutes gets me to stall it unless I keep the revs way up.

Great advice, I will look into your suggestions. Thanks

For a third, 4th or maybe the 5th time what do you have?

I don't want to waste my time writing about ITB's with hot cams, if you have a stock engine with a stock intake. It's why your post isn't getting much traction.

Stock 3.0 from an 82 SC. No mods.

In your backyard..
http://thedubshop.com/contact-us/

Mario is the man when it comes to getting the tune right. At the end of my build we to the car to a dyno and had him log in remotely and do the final tune. Give him a few bucks and take lots of time off of figuring it out. It is still good to learn it all but I would rather do it while I'm enjoying the car. Hope that helps.

What are you using for the TB? stock? You would be better off using a 3.2 intake.
Try picking up the MAP vacuum signal from a different port on the plenum.

Check the fuel cut parameter, if you are using fuel cut you will always have the sharp decel anytime you let the gas fully off. You can fine tune the fuel cut so it has less of an effect, but you will still have to feather the throttle so you don't hit the fuel cut value.
With a stock intake you should be able to run with no fuel cut.

I had on on my 2056 and had similar issues. Make sure all your grounds are good.

Sounds like you could needs som fiddling with acceleration enrichment for the hesitation. Do you know your AFR values right after startup, are you lean or rich?

I did not setup or program the system so am useless with technical questions. The system uses PMOS. Sounds like the dubshop will be the next stop.

Thanks all

Mario @thedubshop is super supportive, I know he is very busy at the moment but hopefully he can squeese you in.

1) This is a tuning issue. Do you have a modern AAR on the car? If so this is fairly easy to work out. You just tell the ECU to adjust the AAR for the "coolant" temp of the car (which is probably your head temp - that's usually how air cooled cars are wired for MS.) The AAR is a fairly crucial part, and is sometimes skipped. You can tune without one, but it gets harder. The AAR in a modern system is constantly adjusting to keep the car running at idle no matter what the engine temp is or load on the car is (lights and windsheild wipers and radio, etc. will drop your idle)

2) Issue 2 - do you have a wide band AFR? Do you have data logs? My MS2 car was doing the exact same thing, and the issue was unless the car was at WOT, it was lean. Lean enough that going from idle to part throttle the car would hesitate and sometimes try to stall. You want to be sure your engine is getting the same values that you have in your fuel table and your AFR table.

In my case I put too much faith in the fuel and AFR table and not enough faith in my actual LOGS that were telling me I was going too lean. Learn to trust your logs and use them to adjust your tables. Post up your log files (with AFR).

Also, you can save your MSQ file to your post. Do that too so we can see what you are doing.

Zach

you may want to indicate what AAR is for the people that dont know.

Aux Air Regulator, AKA Idle Air Control (IAC) valve.

I don't know about the /6 engines, but the /4 had a VERY rudimentary AAR (the valve just closed about a minute after the car started.

A modern IAC/AAR works worlds better. You can find them in 2 wire, 3 wire and 4 wire versions. The IAC that I am using is the 3 wire unit from a Hyundia and cost about $12 on amazon. How you wire them differs depending on which kind of valve you have.

Zach