Help with new MSPNP2

[Hoffbrohaus]

Just bought a new Mspnp and I'm having trouble getting the car to run correctly. I sent this in to diyautotune.com also but wanted to see if you guys had ideas.

I disconnected my stock narrow band o2 sensor, connected my wideband lc-2 to pin 21. Also removed the AFM and plugged in a GM iat in an intake pipe with filter. Loaded the default m20b25 map. Changed the settings for the GM IAT and for the wide band o2 sensor. The car had trouble starting and once it did it randomly bounced idle up and down and when accelerating would get rich and choke the engine.

So I next tried disconnecting the lc2 wideband and the GM IAT. Put back the stock AFM and plugged the stock narrow band o2 back in. Reloaded the default base map and did not change any other settings, then restarted the car. Same results. I then put the stock DME back in to make sure I didn't break anything in the car, started and ran fine.

Stock injectors, walbro 255lph pump. I could not check timing with the PNP plugged in because it could hold a steady idle. What do you guys think?

[ForcedFirebird]

The ignition trigger offset is probably wrong, I see most of the base tunes with 97°, it should be closer to 84°.

[varg]

Are all of your general and engine settings correct? Injector size, ignition offset, TPS settings, ICV settings, thermistor settings?

[ForcedFirebird]

Also, did you install a 0-5v TPS?

[Hoffbrohaus]

Thanks guys that gives me a lot to double check. I didn't get a TPS, didn't see that on the Plug and Play instructions. Do I need one?

We just decided to run out of town so I won't be able to check for a few days. I was just freaking out because I thought it was truly plug and play, I'd plug it in and hit the road.

[redneckvtek]

You dont need the TPS to make it run correctly. There are some settings you have to zero out IIRC if you arent running the tps.

You dont mention hooking up the MAP, just confirming you have done that?

[Hoffbrohaus]

Confirmed. I ran the vacuum line from the megasquirt through the firewall and connected to the intake manifold.

The interesting thing here was the instructions said to use the tee provided to tap into the fpr vacuum. The tube I have going to the fpr is bigger and won't fit on the tee. So I just connected the megasquirt tube to the other vacuum fitting on the intake. That should be fine right? Looks like maybe I have 2 because it's a late model.

[ForcedFirebird]

Any manifold vacuum works all the same.

It's plug and play in the sense that it saves you nearly all the wiring of a typical stand alone. It's just enough to get the engine started.

Having ~13° too little timing tends to make idle (and run) crappy. At work we have e24 with an m30 in it, and I just did the same thing last week with a DIYPnP. The m30 uses all the same settings as m20, changed everything at my office desk before even going to the car with laptop. Ran like crap, scanned back over all settings and realized I never hit "burn" after changing the ignition trigger offset, boom fired right up.

[Panici]

It's plug and play in the sense that it saves you nearly all the wiring of a typical stand alone. It's just enough to get the engine started.

They really should make this clear when they advertise a plug-and-play ecu.
I see folks all the time thinking they can just plug in a standalone ecu and hit the road.


As to your issue OP, I agree with the folks above saying to check the timing as a first step.

Does your ecu offer an option to "lock" the timing? On my MS3X I was able to lock the timing at a fixed value, work the throttle to where the revs were steady, and then check timing with the gun. Although this was on an engine with COP, it may work differently with a M20 distributor?

[ForcedFirebird]

They really should make this clear when they advertise a plug-and-play ecu.
I see folks all the time thinking they can just plug in a standalone ecu and hit the road.


As to your issue OP, I agree with the folks above saying to check the timing as a first step.

Does your ecu offer an option to "lock" the timing? On my MS3X I was able to lock the timing at a fixed value, work the throttle to where the revs were steady, and then check timing with the gun. Although this was on an engine with COP, it may work differently with a M20 distributor?

Yes, it has the ignition lock, but I will say it again. The timing is retarded ~13° as the unit is shipped. The base map has timing figures from ~18°-20°, so with the offset wrong, the engine is actually seeing 5°-7°.

I just downloaded the base files from DIY to verify, first thing you need to do is change this to 84:

[ForcedFirebird]

They really should make this clear when they advertise a plug-and-play ecu.
I see folks all the time thinking they can just plug in a standalone ecu and hit the road.

From DIY's site:

There are three categories of maps:

• Base maps have been tuned on a stock, or nearly stock, example of the car or truck they are listed for. Some have been tuned on a car with oversized injectors and scaled down, but these are generally very close.
• Startup maps are based on a slightly different engine and not final tuned, but should be enough in the ballpark to start a car. They may be replaced by base maps at a later time.
• Tuner maps are from highly modified cars. These may be closer than the base map for cars with similar mods. These are not canned tunes that you can just load before a race and be certain it's right for your car; they are likely to need fine tuning as many modified cars will not have the exact same combination of mods. Please take appropriate precautions with these tunes - if you encounter a lean AFR or detonation, back off immediately and adjust the cells where the problem is happening.

The important part being "Some have been tuned on a car with oversized injectors and scaled down, but these are generally very close." It's close because it may have been tuned with different injectors and scaled to "work".

Even if two engines have the same size injector, but different brand, the tune still needs brushing up. Rarely have I ever had a tune that worked perfect on another car with similar mods.

[Hoffbrohaus]

Thanks 1st thing I'll do is drop that setting from 97 to 84 once I get back on Wednesday. I have a lot to learn before I go turbo!

[Hoffbrohaus]

Ok got back and changed some settings. The car runs way better but still has some issues. Startup runs the revs high, then it settles too low and is rich 15+ even after warming up. At least the engine stays consistent long enough to check timing. problem is my 20 yr old timing light decided not to work. So I'll have to pick up a new one tomorrow.

Here is a link to my MSQ file and logs. These are the settings I checked/changed:

Basic/Load Settings > Engine & Sequential Settings > Engine Size = 2500 ,injector size =178, calculated fuel is 15.7, even firing, untimed injection
Didn't adjust anything else under basic.

Tools> Calibrated thermistor table for Air temp sensor = GM
Tools > calibrate AFR set EGO to LC1 LC2

Ignition settings > Ignition Options > Set tooth Home angle to 84

I'm guessing you guys will tell me to check my timing, which I will tomorrow. But just in case you saw anything else set wrong I wanted to post this up. One interesting thing I noticed was the TPS gauge in TunerStudio wasn't moving, I couldn't calibrate it either. When clicking "Get Current" with the throttle wide open it says 0. So I kept it at the default, 1023.

[ForcedFirebird]

All that looks good to me.

Next, pin the TB open enough for the car to idle in it's own (if it doesn't already), then go through the warm up tables and adjust.

Make sure the o2 feedback authority is 0

[Panici]

...then it settles too low and is rich 15+ even after warming up. At least the engine stays consistent long enough to check timing.

Just FYI, that would be a lean AFR reading at 15+.

Stoich is 14.7, higher numbers then stoich are lean, lower numbers are rich.