Hesitation When Punching Throttle
 

Hello, been on Megasquirt for the past 6 months and have been looking for a solution to this problem ever since I installed it. It's the same question everyone always asks, but I haven't been able to fix it with the common troubleshoots. Problem is when I step on the throttle (anywhere above 100 tps dot) the car has a severe hesitation (a full half/three quarters of a second) before the revs pick up. I have still been having trouble despite trying multiple "solutions" that I've heard of.

The things I've tried are:
Accel tuning (still has an initial lean spike EVEN THOUGH IT IS ACTIVATED)
TPS averaging lag factor
MAP averaging lag factor
Increasing VE cells above idle cells
Moving MAP nipple sources

Still always get that hesitation, and I know others have had it, but for some reason other "solutions" worked (of course it's not the case for me). Could it be the MAP line is too long? (goes from intake through drivers side firewall to ECU above pedal box) It is definitely an issue related to the ECU not picking up the change in MAP fast enough. And I didn't have this problem on the stock ECU eons ago. Any help would be appreciated.

Please don't say "You need to tune your car" - I have tuned it and everything is great and spot on (even accel values) except for this one thing.

My tune is also attached

Thanks

You need to tune your car. If everything was "spot on" it wouldn't have this lean hesitation when you tip in.
Look at your AE settings in particular.

And, since you've researched this already, you should know to post a tune file and a log as well that shows this lean/hesitation condition.
Otherwise we're all just making shots in the dark.

I'll post it later but I wondered if someone had the same problem and could just share their experience. Car does not really need to be tuned like I said because everything else is perfect. Whatever it is it's a little correction, not the whole tune

It sounds like it needs more fuel during AE. Your tune file and logs will help confirm that suspicion.

Make sure that you've got TPS, kPa, and AFR in the logs, since this will make it easy to see when you open the throttle (TPS) and how quickly the kPa and AFR respond.
Info helpful! Shots in the dark, not so much.

I thought the same because it does have a lean spike but there is no matter what a lean spike for a hair of a second right before.........every time. No matter if I put my AE to the moon or not, it still has the same lean spike and hesitation

I know how to give you guys a log lol. I'm not that newbish:naughty:

Log will come tomorrow :bigtu:

You need to tune your car. Your AE settings are bad.

https://cimg0.ibsrv.net/gimg/www.mia...9c05ab34ed.png

AE is very straight forward. Use a basic map from Rev or DIY and don't touch it ever again.
Miata engines like 14.7 for drivability, any leaner than that and you'll get slight hesitations. You can get away with 15+ at highway cruising.
But otherwise adjust your afr table for 14.7 where you have 15 currently.

Look I've already tried tuning AE. I'm coming here because after trying things like these I still get no improvement. I don't know how else to describe it, but there is always a lean spike that happens EVEN WHEN AE IS ON. I've tried setting AE literally to it's highest setting and everything in between. It's not AE. If it was AE I wouldn't be on here. I don't know what else to say, but if anyone has any other ideas other than AE that would be great. Still going to post a log later today so you guys can see what I've been talking about

What you are describing is AE, you're being stubborn. Or your TPS isn't hooked up.

Then I guess I'm describing it wrong. I've tried AE for 6 months and have had absolutely no improvement. The settings you guys would consider normal aren't even close to fixing it. I'm not trying to waste your guys' time with an AE question, I've read about it a ton already and have already tried it.

MAP hose length has been tested - it really doesn't matter. Unless you've got it pinched somewhere. Again, a log is needed.

Hey Melvin, I just downloaded your tune and have a few comments. Under Engine and Sequential Settings it looks like you are running on "untimed Injection" which seems to be batch injection instead of sequential injection.That might cause some of your tip in issues but not all. The second comment is that you are using TPS based AE with values added that are incredibly low. On my personal setup I am running a 1.6 engine with sequential injection and for value added I am running values added of (0,25,45,60,65) for tps dot values of (0,22,200,475, and 1000). I am not saying that I am doing it the correct way or that I am correct, just that you cantry upping your values of acceleration enrichment to follow some kind of curve. Maybe you can try fiddling with your slider scale to favor more tpsdot as opposed to map dot.
Your current acceleration enrichment values don't actually add any meaningful enrichment.

Edit: Also your trigger Accel Mapdot threshold kPa/s is set to 999 which is an incredibly high number. As in you won't get any accel enrichment until you go above that number. For reference, my number is 25.

Even if you've tried different settings, your current tune will give any miata hesitation when you punch the throttle. Your current AE settings add a maximum of 2% fuel. That is going to do jack shit.

I don't use much basic AE, mostly EAE, so I cannot comment on what are good AE-only settings. But I can assure you that my logs show at least as much as 50% extra fuel added on hard punches. This prevents leaning. So, if you are adding only 2%, I can assure you that is not enough.

Sooooo. Information provided. Let's hear how the recommended changes HERE IN THIS THREAD affect your situation.
Or, you know, you could keep telling us that our suggestions won't work.

Please don't be one of "those" guys. They rarely last long on the site.

Also, post a log file of the condition once you implement the recommended suggestions.

Remember when you punch the throttle, you're changing the map, which moves to a different section of the fuel table. Often cells above idle have a higher VE than the idle cells. So in some cases, I've found a car to respond well with AE as low as 2% where you have it. I could turn AE up and turn the fuel table down, but it's usually easier to turn AE down.

Also, start ignoring the lean spot, like, now. Tune according to how it responds to throttle input, not what the gauge is telling you. That's a delayed reading from a rush of air that entered the engine a few feet from where you're measuring. And with throttle response, every millisecond counts.

Fix your AE settings. Your current settings, you may as well have it turned completely off. It's not doing anything.

Thanks for more info. As far as my low settings, I left them there after trying higher AE values (all the way up to 40 added). The current tune would probably hesitate like you guys are saying, but since the higher values weren't working for me I just lowered it that's all. I will up the AE mainly just to please you guys lol and show that it still hesitates, or there is a possibility I missed something. I'll post a log with all the info in an hour or so and I'll change the AE and do another log. Till then