I bought my 90 Miata after it was wrapped around a phone pole by a 16 y/o. It's drivetrain now resides in the Locost (Lotus 7 replica) I am building. I went to fire it up today for the first time since I've owned it and I can't get any love from it. I admittedly goofed up a bit routing the fuel lines and it may be the problem, you guys would know more than me.

Here is how it went down. I turned the key and heard the fuel pump whine. Good, looks like FP has power. I turned the key to the next position and it started cranking but wouldn't hit a lick. I started pulling plug wires checking for fire (which was good) etc. and at some point noticed that the fuel pump ceased to whine. I decided since it wasn't getting fuel apparently I would double check my line routing. I quickly noticed I had hooked the fuel suppy up to the end of the fuel rail with the regulator. Oops.

I then decided that I must have blown a fuse or burnt up the pump. I then pulled the plug from the top of the tank and checked for voltage. The sender side read 12V but the other side had nothing. So the pump should be OK, it just isn't getting power. I checked the fuse blocks for blow fuses and don't see any and now I'm stuck. Why is the fuel pump not getting power?

What now? I was hoping you Miata gurus could help get me going.

Thanks in advance.

 

Not completely sure on this checpo but think that your fuel pump relay coil is grounded by a switch in the air flow meter. Do not have any schematics here at home so will check in the morning when get to the shop and wiring diagrams. mazda used this type of setup a lot in the early to mid 90's. Try opening up the air flow meter flap manualy with the key on and see if the pump starts up again.

 

Thanks Huey. I had a big hole in my intake ducting that wasn't allowing the airflow meter to work. I taped it up and it started right up and ran fine.

I appreciate the help.