Beginner tips to tuning a standalone ecu

[Thrasher13]

I have an 89 hatch with a 5.0 ho with some goodies and I've recently purchased the megasquirt plug and play standalone from diyautotune.com. I've never tuned a ecu before so I'm just now learning about it and was wanting to hear from more experienced members who could answer some questions I have and maybe give me some tips to begin with. I haven't connected the megasquirt system yet but have been reading the Manuel and tuning guide every free moment I have. It's a complex system and knew it would be but I'm ready to learn how to do this. My car is far from stock but still naturally aspirated (for now) with stock internals but basically have every bolt on so I know I definitely need to fine tune the tune sent with the system to start with. I was wondering about setting my timing from the distributor, the Manuel says I need to set it to manufacture setting but I'm not sure what That is, I've been told 10 and I've herd 14. I personally run 24.6 base timing For better gas mileage, but people tend to look at me funny when I explain that to them lol. Ive recently been introduced to total timing told I should start adjusting useing that. However I haven't yet had the time to mess with it but I noticed in the ignition tables that I would be setting the total timing and it seems knowing around where I'm at right now would help. If anyone has any advice or suggestions I would appreciate them a lot, again I am a beginner with all this and don't know abunch of the terms and methods used in ecu tuning so I may need things explained.

 

[FISHTAIL]

I have zero experience with your system, but I can at least answer one of your questions. Base timing is 10degree's. I presume they want you to set it there because that's the value that's used in all the timing calculations.

People bump their timing to 14 regularly, but all that's doing is essentially giving 4 degree's of global spark adder to the timing tables in the stock ECM.

Total timing refers (I believe) to how much total advance you are running. So base timing is set to 10, but your total advance might reach say, 35 degrees, depending on load and RPM.

 

[blownfox]

I think the ms tells you your timing should be set to 12 degrees. Since this is your time using a standalone, I would order the EFI live with the mega log recorder/ viewer. I think it is $80.00. The EFI live will help maintain your fuel to air ratio throughout the rpm's, you will need a wideband for this. Matt at DIY is an awesome guys and will help you with most if your questions. Corral is also a great site for support.

 

[FISHTAIL]

You may want to do some reading over at EECTuning.org too.

 

[Thrasher13]

Thanks for the help, I checked out EEC and it seems to have some good info in it. I'm most Likely going to get efi live to run my tune for daily driving so it can just adjust my cruising speed. I've been playing with my timing some today and have been trying to work the bugs out of my car before installing the megasquirt. Just wondering if any of you guys have some ideas what could be going wrong. I've been running 24.6 base timing which turns out to give me 44.5 total timing. At times my car would randomly skip (more often under a heavier load). Today I set my base to 10 which gave me 32 total. The car seemed to drop off power with about 40% throttle and around 3500 rpms. It's hard to explain what it does, it's not a skip but more of a lag cuz the car still drives a pulls. So I changed to 12 base timing and it seemed to help but still was there at 70% throttle and now I'm at 14 base and it's gotten even better but still seems to lag. I'm sure I could go with more timing and get better but there is obviously a problem present. If anyone has any ideas I would greatly appreciate it. I'm out of ideas, I've changed the distributor out (with a used one) changed the ecu with one that I know is fine, today I tested my icm at my local Oreilly and was hoping that was the issue but it tested good all 10 tests. I'm starting to think its a possible ground issue or possible vacuum leaks. Any ideas? Or ways to trace out my issue? I'm afraid it's till going to do this with the megasquirt and cause tuning to be extremely difficult.

 

[FISHTAIL]

Skip? Sounds like it might be lean. I've been working out the fueling on mine, and skipping is exactly what it does when it goes lean. Check your AFR.

 

[Thrasher13]

Could over advance timing cause a lean mixture? Il have to wait untill I get my wideband installed before I can check the afr

 

[1990fox347]

SPEEDBRAIN computer

hey guys i picked up a speed brain computer i came across ame out of a foxbody that ran high 8's low 9's i was going to use this on my car but decided im not willing to toy with a motor i sank as much money into as i did. just curious if anyone is interested in it and can maybe gimme a ball park figure as to what this is worth. thanks

 

[FISHTAIL]

Could over advance timing cause a lean mixture? Il have to wait untill I get my wideband installed before I can check the afr

Lean? No. Detonation, yes. Lean would only be caused by insufficient fuel for whatever the engine is aspirating.

 

[Thrasher13]

I don't think my car is getting enough fuel which is why it's lagging like I described, I'm still running a stock fuel pump an regulator on a factory tune. I have gt40p heads ported with a bigger tb. Egr delete, cai, ported typhoon intake, with 24lb injectors and a maf to match. I'm sure it's likely that I have a lean afr and I wa planning to change the fp and regulator in due time. This "lag" is feels like all of the spark plugs are fouled (but their fine) and it only happens when the car is at operating temp with a load and partial throttle.