Very first DIYPNP install - won't idle
 

Hi guys. I attempted to put in the DIYPNP this weekend and it didn't go well. I couldn't get my stock '95 to idle. Here's what I did after plugging it in place of the factory ECU.

• Ran MAP hose to ECU. (Incidentally, I ran it on the outside of the car because I never could get it through the firewall.)
• Deleted the MAF and put the IAT sensor in its place
• Connected Megasquirt preloaded with this basemap
• Calibrated TPS
• Calibrated IAT
• Selected Narrowband from Calibrate AFR menu (I have an LC-2, but I wanted to see if I could get the car running first before any tuning)
• Set the timing advance to 10, started the car, and began the Trigger Wizard

The car wouldn't idle, and the only way I could keep it running was by giving it a little gas. I tried setting the ignition offset from -5 to +15, but that didn't seem to make a difference. After half a dozen attempts, the car wouldn't turn over. I plugged the factory ECU back to see if that would make a difference. Still wouldn't turn. :noes: I about had a heart attack. I thought I ruined my engine for good.

Battery just needed a charge.:doh:

Attempted the megasquirt again with the fresh battery and I never could get it to idle, so I gave up and put the factory ECU back in. I'm sure I'm missing something obvious, but I'm new to tuning so I don't know what to look for specifically.

I logged the results of the car running with me (not-so-consistently) feeding it gas. File here. I appreciate any feedback.

Edit: I should also mention I tried adjusting the timing manually by loosening that 12mm nut behind the driver side valve cover, both with the factory ECU as well as the Megasquirt. The slightest adjustments were noticeable on factory ECU, but seemed to make little difference on the MS.

<p>fuel.</p>

Can you elaborate?

<p>add some.</p>

I don't know what I was expecting.

:laugh:

Seriously tho, tune the car.

That's the goal.

I'm just feeling a little lost. And frustrated. I've never tuned a car before and I wanted to learn on my N/A. I moved the required fuel from 11.6 to 14, but that didn't seem to do much. It's not as simple as turning a screw on a carb, that's for sure! I've spent a few hundred bucks on parts, several hours soldering, reading manuals, other forum posts, the famous ONE BIG POST, etc. I just want to get this thing running, so I have a starting point.

It must be amusing to watch a new guy struggle; to not know how to do something as simple as deliver sufficient fuel to his engine. I get it. I was really just hoping someone could nudge me in the right direction. We all have to start somewhere.

From the original thread you have 550cc injector? Are they on the car or stock injectors?

I feel your pain.

No really, I do.

What is the wideband showing? is it lean? Bump up the VE table cells in the 10-45kpa and 0-1500rpm region

Why did you bump up req_fuel? do you have smaller injectors than stock?

Thanks, even a little empathy is helpful. :) I didn't have the WB connected for the initial trial. It's an LC-2. Obviously, I'm planning on putting it in, but I wanted to see if I could get things going first before I committed to installing it. (I wasn't sure if it would be compatible with the stock ECU if I needed a failsafe.)

I have the stock injectors on there now (265cc, IIRC). I do have 550s on the bench ready to go. Again, I wanted to try first with as few variables as possible. I bumped up the fuel because it felt like it needed more and that was the desperate move of someone who didn't know what he was doing.:x:

What do you think, should I install the LC-2 and give it another go with the settings you suggested? Or see if I can get it to idle with the stock O2?

it's gonna be 10x harder without a wideband if it doesn't fire up on the base map as is.
and it makes literally zero sense not to install one because it takes all of 10 minutes and you'll still rely heavily on it when using megasquirt. so yeah, I'd install it.

Also re-load the original unaltered base map, don't touch req fuel unless you changed injectors, don't touch anything else besides the tps calib, the ait calib, and the wideband calib/setup to get the ms to communicate with the wb. put whatever screws you touched on the mani/tb back to how they were initially.

the key here is keeping as little variables as possible so you know what does what and what causes what and what to undo if you suddenly mess something up

Alright, I'll give that a try and report back.

To be clear, I didn't mess with any of the settings (Req_fuel, timing, etc.) initially. I only did that after the 10th time trying to get it going.

i had did issue before.. this forums advice.. read the damn manual.. lol ..which i did and guess what it feels great figuring it out by yourself lol before you do those stuffs.. u have to fix every single settings.. PS MS needs a Wideband and use the GM IAT sensor connected.

<p>If&nbsp;you can start the car, but it wont idle on its own, it typically means you don't have enough fuel--It's pretty simple.&nbsp;That or your idle valve settings are completely botched, which they shouldn't be since youre using my basemap.</p><p>You shouldn't be locking the timing and trying to run trigger wizard if you can't maintain an idle.</p><p>You really need to hook up the WBo2 and see where the AFRs are.</p><p>Logging was a good idea, but hosting it on an online storage drive&nbsp;where most worksites block due to security concerns was not--upload it here.</p><p>&nbsp;</p>

Thanks for the words of encouragement

I will install the WB and work on getting the idle going steady before messing with the timing. I tried uploading the file first, but it failed. I tried making it a zip, removing dashes in the name, etc. It's not a big file, either: 115kb.

Attachment 233318

<p>odd. MSL has a&nbsp;5,048,576b&nbsp;limit.</p><p>the log will help to see if it's an&nbsp;idle valve issue, fueling issue, parameter issue, calibartion issue, etc.</p>

I installed the wideband and got it to idle thanks to your tip. I bumped up each number in the highlighted cells by one. At first I was making broader tweaks (more cells, bigger incremental changes). I didn't realize these adjustments were within a gnat's whisker. The pros are probably saying DUH, but I didn't know better.

So there's a tip for all you other n00bs who may come across this: make small changes in a small range.


https://www.miataturbo.net/attachmen...ine=1434500229


I still need to run my cables, into the cabin since I just ran them on the outside of the car to verify they were working. I also still need to set the timing, but at least I have hope that I'm progressing. Thanks for the help.