MS PNP on 1.6 SC miata - no start
 

Hi everyone.. I recently installed installed ms pnp on my car and i'm having a hard time getting it to start. This is my first time to install a programable ECU on my miata so I would definitely say i'm a newbie at this.

So here's what i have:
'97 1.6L "euro spec - non immobilizer" miata with a JR M45 SC, LC1, stock injectors, JR AFPR removed, AFM replaced with GM IAT, vtps from an AT miata installed and calibrated thru megatune 2.25.

I'm using the base map that came with the MS PNP - MSPNP MM90-93 without AFM. Configured for LC1 Default settings, Exhaust gas setting already changed to wide band, EGO switch point - .392v.

All other base map parameters unchanged.. please help me get it to START.

For starting, the areas you want to focus on are the Cranking Settings and After Start Enrichment settings. I've found that what is in the basemap will get you going if it's fairly warm out. If it's pretty cold where you are, you probably need to crank in more fuel. Just take it a little bit at a time to avoid flooding.

I've attached my MSQ. It gives reliable starting but is tuned for 350cc injectors. You'll want to increase the pulse widths in the cranking table by a scale of 1.7 (350/212) to give this a try.

hornetball: I tried opening your msq but it won't open. if you can maybe send it again. Thanks though.

Just want to add also that it's most likely not a problem with the fuel system. When I turn the ignition on, I can hear the fuel pump whine and COR click. And I when i checked, the spark plugs, they're wet with fuel..

I also didn't for get to remove the 10 amp ST SIG fuse before i turned on the MSPNP..

Uh, it most likely is a problem with the fuel system. Your engine is flooded. Reduce the pulse widths in the cranking table.

Tps/ iat sensor calibrated?

Have you set the required fuel? Injector/engine size set correct?

Here are some pics of what i have in mega tune:

Greg this is the VTPS calibration:

https://www.miataturbo.net/attachmen...ine=1330681724

Chacer this are the constants.. haven't changed anything here yet.

https://www.miataturbo.net/attachmen...ine=1330681724

Hornetball you maybe right that i'm flooding the engine.. this is my crank settings.. don't know how to go about adjusting it yet..

https://www.miataturbo.net/attachmen...ine=1330681724

but i did adjust this TPS value for flood clear..

https://www.miataturbo.net/attachmen...ine=1330681724

Some other pics of what i have..

I switched the Exhaus gas settings to wide band.. set the switch point to .39
= 14.7 AFR

https://www.miataturbo.net/attachmen...ine=1330682109

https://www.miataturbo.net/attachmen...ine=1330682109

https://www.miataturbo.net/attachmen...ine=1330682109

https://www.miataturbo.net/attachmen...ine=1330682109

https://www.miataturbo.net/attachmen...ine=1330682109

A few issues:

1. Double check your EGO switch point. Normally, a wideband has a 0-5VDC output and stoich will be around 2-2.5VDC. BTW, this has NOTHING to do with your starting problem -- it doesn't even come into play until after you're started and warmed up.

2. Take a good look at your gauge screen. See what I see? Coolant temp = -40°F (vs. IAT of 93°F)!?! Now go into the cranking pulse width table and correlate the pulse width to -40°F. 8.8msec of injector time. That's a bunch of fuel, my friend. No way your car is going to start on that. You've got to track down the problem with the coolant temp sensor.

3. In spark settings, reduce your cranking advance angle to somewhere between 0 and 10 degrees. When you finally do get a combustible mixture, this will keep the engine from kicking back against the starter.

This thread might help you a bit:

https://www.miataturbo.net/megasquirt-18/wue-cranking-more-62872/#post821778

Agree, looks like clt is way off. And that will dump fuel in.

Heres a few of my basic settings. Hornetball is right though, something is wrong with the clt. Are you using the OEM sensor or aftermarket?
https://www.miataturbo.net/attachmen...ine=1330800932
This is for 460cc injectors & temps are in deg c not f. You can calculate your pulsewidths from this table by using the pulse width calculator elsewhere on this site (do a search).
cheers
Rob

ok.. double check my harness today and everything checks out right. (my car is wire tucked) I thought the CLT wiring wasn't right but it was: CLT blue/white wire to 2Q, black/lt green wire to common ground JC-02. BTW my CLT sensor is stock.

I noticed on my Cranking Settings that cranking pulse width temps says "CLT only. I'm thinking of changing it CLT, MAT average. Is that ok? I have a GM IAT sensor.

Hornetball thanks for the link. What i got there was the 4 stages of engine operation:
1. Cranking setting/pulsewidths
2. ASE
3. Warm up mode
4. Normal mode

and some warm up enrichment tips as brainy said.. just have to go through stage 1 and 2 first...

Coolant temp is used all over the place. You really need to get it figured out. How many ohms between blue/white and black/lt green?

subscribed.

Measured the resistance of my coolant thermosensor - CLT today. I got 1.7 kilo ohms. Temperature here was at around 30C or 86F. The CLT gauge on MT seems to get a reading though I can't see the exact value. This is when I tried to crank the engine..

I have some datalogs but i can't seem to figure out how to post them or attach it to e mail to DIY autotune.. :noob:

i've been reading MS1 Extra basic manual and came across this:

Original Equipment Temperature Sensors:
If you are using temperature sensors that are NOT MS SENSORS (e.g. your original equipment sensors) then you will need to generate 3 inc files so that Megatune displays them correctly. (2 inc files are generated for the Air Temperature Sensor and 1 for the Coolant Sensor)

Download a desription on how to set up your ECU and MegaTune with your sensors here: WORD FILE - TEXT FILE

The MS recommended sensors are from a GM motor, part numbers:

The links "WORD FILE - TEXT FILE above aren't working. Anybody here know what those links are saying?

You use a program called easy therm to generate a firmware file with the proper resistance values programmed into the MS.

then you the three .inc files must reside in a specific folder for tunerstudio (or megatune) so that the laptop displays the correct temp values based on your inc files (the same the MS is using).

the 90-93 MSPNP without AFM basemap has these values in the firmware, and the inc files should be withing the package the firmware came with. It would work with your 97 since the CLT sensor is the same, and I'm assuming you have the GM AIT, if not and youre still using the MAF, the air temps will not read correctly.

Braineack thanks for the info. I looked in the the MS PNP msq files and under the MS PNP MM90-93 without AFM default files is the default deg F. Is that it? If I add that to my current msq then it would read the CLT? MY current file name at the bottom of MT screen now says:

C:\Program Files\MegaSquirt\MSPNP MM9093 without AFM\default_files\default-degF.msq

BTW I have a GM IAT and I think it reads correctly..

Hi guys. It's been a while since i've updated this thread. Anyway, my miata is already running with the MS PNP 90-93 ECU. As it turns out the wires on the coil pack socket were mismatched after we pulled the pins out of it during a wire tuck. After that has been resolved the car fired up right away with the base map.

My problem now is with the AC. A few months back when my car first fired up with the MS PNP, the AC worked but after some time the AC just didn't work anymore. I then put back the stock ECU and the AC is working fine with it. So I'm now thinking there's something wrong with the MS PNP... that I may have fried something in there just like Holy driver on this thread:

https://www.miataturbo.net/showthrea...t=20954&page=4

Also when I connect Pin 1Q ( AC switch ) to pin 1J ( AC relay ) the AC works!
This is with the MS PNP. From what i've read on the thread i've posted above, MS PNPs have a circuit on the daughter board for the AC so i'm thinking that's where there's a fault on my MS PNP...

What do the you guys think??? Is my MS PNP Ac circuit fried?

BTW, I haven't done any tuning yet as the car runs fine with the base map. I'd like to sort out the AC problem first before all that..