Dear Awesome Miata community,

I own a 1991 miata and I'm in the end phase of vvt swapping it. The engine is in and it cranks over. The engine used is from a 2003 NBFL donor car. It ran before I took it out.
I use the MSPNP pro ecu.

Currently I have a few problems:
- The TPS ('03 TPS) is not reacting in tunerstudio.
- The car cranks but doesn't start => Checked and changed sparkplugs. Spark plugs are dry to wich is not normal => Injectors work when triggering them with the testmode in tunerstudio, as does the ignition ( testing coil A triggers 1 and 4 and coil B triggers 2 and 3 as it should) => when holding sparkplug against the block, the spark is clearly visible and strong. In the attachment you can find how I did the ignitor bypass.
- The fuel pressure is only at 3.6 kPa according to the tunerstudio guage wich is strange. I use the 91 FPR mounted upside down as stated in the megathread. There is a kink in the return pipe when I tried to bend it straigh to clear the intake manifold. But fuel is going through.
- the box "not RPM synced" is red, what does this mean ? how can I resolve this ?
A screenshot of my current view in TS is in the attachments

I used the VVT megathread from the awesome Savington as a guide to do everything. However the thing I skipped for now is the wiring change needed for sequential injection. I changed this in the 01-05 basemap on the megasquirt (from sequential to off).

How can I resolve these issues ?

Very Kind Regards,
Cedric Van Roeyen

 

What fuel rail & fuel pressure regulator are you using? I just did the swap, and I got the fuel feed and return lines backwards. The forward most hard fuel line is the return, and goes to the fpr.

 

Thank you for you response.
I'm using a 1999 fuel rail and a 91 FPR.

It's always hard to check wich is forward :P
Is more towards the bumper forward ? or is to the windshield more foreward ?

Kind Regards,
Cedric

 

The fuel pressure guage in TS does not work correctly unless you have wired in an aftermarket fuel pressure sensor.

 

Thank you for the clearification. There is pressure in the hose because I can feel more resistance when squeezing one then the other. But it is possible I connected the wrong hardline to the return pipe on the FPR.

 

Forward=closer to the bumper
aft=closer to the windshield

If it's too tough to tell which line is which, you can always just swap the hoses and see if that fixes it. Don't forget to open the gas cap to relieve pressure before pulling the fuel lines.

 

It seems that I had wired the Fuel lines correclty.

What did you do to get your swap running on your pnppro ? Which ignition type did you use 4G63 or the miata 99-05 ? Any other things that might need to be changed ?

 

I would start with diagnosing your known problems... TPS, for example.

Do you have good crank and cam signals? Timing set?

 

Regarding your TPS: do you see some signal in the calibration tool, but it's not changing when you press the pedal? If so, you might need to shuffle the wires around. It's only three wires, so trial & error should make short work of it.

*EDIT* what Roda said.

Regarding fuel: have you looked at your composite logger to confirm that you're getting cam and crank signals? I think fuel will only inject if the ECU is getting both signals.

 

Thank you for your reply,
How do I check this ?

 

I don't get any thing when cranking. There is some sort of blue wavy animation but as soon as I crank it stops.
What do I have to configure in TS to see the signals ? I used the CAS spicing method on the VVT megathread.

EDIT: In the calibration menu I get zero twice, so no input at all.

 

I'm pretty new to using the tool too, but you have to save the log. Then load it in the same high speed logger tool tool there in TS. In the bottom right, there will be several pages listed. My log was on like page 5 of 6

 

There is absolutely nothing recorded :( when trying to open the file it sais its empty

 

I think that is an indication that it isn't getting signal from one​ or the other sensor. Share your wiring, and we can try to diagnose. I found it very hard to find the correct pinout for the cam sensor. Gnd is closest to the driver's side, signal in the middle, +B is closest to the passenger side.

 

how did you wire the TPS? How did you wire the cam and crank sensor? You need to do a composite logger while cranking. that will tell you if you are getting any signals or not. NOT the normal datalogging but the composite logger.

Edit- Also, what are your ignition settings?

 

OK... sounds like you are trying to get step 10 to work, when 1-9 haven't been completed yet.

First... read the manual, and follow the steps. Start with the crank signal. If you're not getting a crank signal, nothing else is going to work.

You should have three wires to the crank sensor: 12v+, signal and ground. These are normally the shielded wire set out of the MS (I don't have a Pro, so yours may be different). The ground has to go back to the MS. Check continuity and voltage on these wires, and make sure you're wired into the correct factory wires on the sensor. You should be able to find a wiring diagram online.

Take this one step at a time, and don't go on to the next until you're sure you have the previous one completed properly. It's tedious, but if you take your time, you'll get there.

 

Screenshots and photos of everyhing will follow soon. I wired the cam and crank following the wiring on the "definitive VVT swap megathread" made by savington on this forum. Which is going from the cas to the cam and crank sensor.

The tps is wired using the mspnp pro 90-93 manual. I will check the wiring again when I'm home.

Thank you for all the help so far you all are awesome

 

Hello,

The Cam and crank sensor wiring:
12v (extend 90-97 wire to both 99-05 sensors):
90-97: White/Red
99-05: White/Red

Cam (extend to Cam sensor only):
90-97: yellow/blue
99-00: grey/blue
01-05: grey/blue

Crank (extend to Crank sensor only)
90-97: white
99-00 grey/red
01-05 violet/white

Ground (extend to both 99-05 sensors)
90-97: black/light green
99-05: black/blue

I double checked it and it is correct. all wires do measure through and the 12v is present.
A screenshot of my ignition settings will be in the attachments

The tps is wired as seen in the attachment. These wires measure through aswell but there is no 5v at the connector.

 

get a composite logger done so we can see cam and crank sensor signals. Did you make sure the crank sensor was adjusted correctly? Most people gap it with a CC or razor blade.

 

OK, this covers what you did at the engine end. How did you wire things up at the ECU end? I did my swap with a non-PnP MS3/MS3X, so I may be wrong, but I don't think you can just plug in the PnP 90-93 MSPro and have it work with a VVT engine, even with the above changes. I think you also have to route the crank and cam signals to the proper pinouts for that ECU. Same with the TPS, which could explain why you don't have 5V at the TPS...

Did you follow the pinouts here? : MegaSquirtPNP by DIYAutoTune.com

Worry about your basic wiring before you get concerned about settings in TunerStudio.