Quick MSPnP Question
 

Hey guys, was trying to start my car for a little while today, changed the fuel req and worked out the cranking pw and enrichment tables as directed by the manual. Just as I was finishing for the day I noticed I was not getting any readings from the manifold air temp gauge on megatune. Is this a good indication of the IAT being improperly wired? Also is there any way to change the AFR parameters to work with the NGK AFX wideband, its output is 0 to 5v linear, 9.0 to 1 through 16.0 to 1. Any help appreciated. Thanks!

yes the AIT is most likely setup wrong. I dunno why you are messing around with the maps etc since the pnp comes prelaoded with a map, but oh well. Setting MS up for the AFX should be no problem go to the configurator and pick the .6-1.1 lamda WBoption or just reference the AFR vs voltage and od al you tunning in voltage. https://www.miataturbo.net/megasquirt-18/setup-afr-target-table-ve-8888/ Also ask Jerry at DIY he should be of more help

I'm guessing you did an AFM/MAF delete at the same time? If the IAT sensor isn't wired into the connector properly you'll get -10 degrees in MegaTune and the car won't start in most cases...

I'd reload the base map and check that wiring for the IAT sensor as per the manual. Shoot us an email if you have any trouble...

OP only entions altering the REQ_Fuel, ASE and warmup settings, to me that means he has non-standard injectors. Hence the altering of the .msq

Yeah I'm running 550's and an AFM delete, guess that information might have been helpful. The car is also a '91. Thanks for the replys, I'm going to check continuity to the IAT connector when I get home. Thinking thats most likely the issue.

You're on the right track-- get the IAT hooked up (check for a valid reading in MT), scale the three items above for your 550's, and try to start it. Then if it still doesn't start you may find you need to increase the cranking PW just a bit to get it to pop off as they may end up a bit small after scaling them down. Better too small than too big though, if they're too big you'll flood the engine and then you'll be fighting with that, it's better to slowly increase the cranking PW in small amounts until it starts.

Unfortunately the IAT is wired correctly, still no reading on MT. Going to check continuity to main harness now.

Check it with the AFM plugged in-- see if you get an IAT signal then. Not worried about running the car, just plug the AFM in to see if you get an IAT signal....

Ok, turns out I'm just a dumbass, a past 02 clamp install left a certain wire unattached. Still didn't get it started but I'm getting IAT readings now. Probably just need to make slight adjustments to the cranking PW's. Thanks for all the replies and thanks to diyautotune for the proactive customer support. :bigtu:

^ hearing of their good support is one reason why I'll be getting a PNP in a couple months.

No problem man-- I'm sure you're right that it's just cranking PW with the 550's, the manual and my comments above should get you going, key being to start small and add a bit at a time so you don't flood it. If you need us just drop us a line....