bp4w swap using CAS in 90 car with mspnp. Help me (re)start it,
 

So if you've seen my build thread you know my setup, if not its basically a 99 motor in my 90 miata with mspnp and dw800 injectors.

I went for my first start today, i flashed the 99 base map on the car, setup the cranking pw for the new injectors (new injectors are approximately 45% larger than my old 550's, cut the old working cranking settings by the same amount) and finally got it started by moving the CAS around.

Now i shut it down after about 30 seconds to check over everything and it wont start back up. It actually won't "catch" when cranking which leads me to believe its my cranking PW settings. They were at 3.8 @ 80 degs and 2.4 @ 100degs. They are now at 1.9@80 and 1.3@100. Cant get it started now that its warmer after the initial start .

I think the timing may be way off too though, because i just slapped the CAS in the motor. What is the best way to go about this, is there a way to mechanically sync the CAS with top dead center to know my timing is close and not 180 off? Or should this be done within the MS software itself.

Bleh, help if you can. I'm gonna keep playing. THanks guys.

Do you have a timing light?

Curious as to the answers as in a couple months i'll be in the same position as you

yeah, have a timing light. Until i can actually get the thing restarted there is no accurate way to check the timing though.

I've flooded and dried out the cylinders 4 times now. Looks like timing is wayyy off, because i actually took the cranking PW down to 0 and slowly increased them. No start.

THen I put the cranking PW where they "should" be and played with the timing in the MS spark settings, going from 0 to 140 degrees of trigger angle with no luck. Must be a combination of the two..

Got it started again. Idling at 2,000 rpm but i let it warm up some. Gonna set the timing on it and go from there. I ended up finding TDC on the front piston and put the CAS back in with the notch up. I also followed the MSPNP guidlines exactly to find my cranking PW.

Not sure if there is a vac leak somewhere? Why else would it be idling at 2k. Gonna check for vac leaks now as well as play with the idle adjust settings.

Got the idle down to a reasonable level by adjusting the frequency of the idle valve.

Super weird issue I have now. The fan(output 2) is ALWAYS on. It wasn't doing this until I had my miata hooked up to another car charging it in the garage and forgot, then switched the key (thus the ECM) on. Immediately I heard the fans which wasnt right, switched off they key and realized what I had done.

Did i fuck something up? Anything I should check for.. I even tried turning output 2 (fan) off entirely in tunerstudio, but it stays lit up at the bottom. Dumbass me.

Edit:starting to lean towards a stuck fan relay, the MS settings never changed from when the fan wasnt turning on, the ecu works great otherwise. Unless you can fry just the fan output circuit or something. Both AC and the other fan are coming on.

curious, but why such big injectors on a relatively stock motor? you going e85 or something?


I have a 99 in my 90, with I/H/E and a BP5A cam with MSD switch, red top injectors, no tune at this moment but that will be changing soon.


im not too familiar with the subject, but iirc i thought i read theres something about having to modify the ignitor?

Yeah, I have plans for e85 and a slightly larger turbo down the road. These idle great so far (and i've barely tuned it at all).

Sorry for such a useless thread, but updating. Think I may have fried the relay somehow, ECU works in every other aspect perfectly.

Found this thread too: https://www.miataturbo.net/megasquirt-18/my-fan-56942/

Looks like I'll try disconnecting the ecm and make sure the fan still comes on with the key to test the relay.