Fuel Pump and injectors not engaging/ Electrical?

Asked by curious_party Sep 04, 2012 at 05:50 PM about the 1991 Mazda MX-5 Miata

Question type: Maintenance & Repair

I have a 1991 Mazda Miata and I can't get her to start. She'll crank but wont catch (she sounds like she right there but just wont turn over). At first the electric drivin fuel pump wouldn't go so I replaced it, now the new feul pump will run, but only when I run a live wire through the circuit(bypassing the computer). And when I do that, she still won't start. I tested the air intake with another that I know works so I know its not that, and when I spray starter down the air intake she starts to run then sputters out. So I know I'm getting spark and air but the fuel I'm not sure I'm getting, if not from the fuel pump then from the injectors, I neighbor of mine who owns a miata says that if it were a problem with the injectors directly, only one wouldnt be working. I whiched out the relay for the injectors and that wasn't it. I figure something in the cars computer is not letting the fuel pump or the injectors run, but I'm not sure how to test that let alone how to fix it. Does anyone have and idea what my next step should be?

5 Answers

61,265

Cam or crank position sensor tells the injectors when to fire. Could be a stand alone sensor or part of the distributor

4 people found this helpful.
46,455

Under the hood is a fuel pump relay, and also there is a fuse under the dash for the control circuit to the relay. I would take an amp meter and test both since it seems there is no power to pump. Also I had a bad experiance with clogged fuel filter which it located under ther car in front of the rear passenger tire. Here a link to the fuel filter process: http://www.youtube.com/watch?v=bQKUgqB_jaQ

10 people found this helpful.
60

Checked fuel pump relay under the hood, it's getting power. Replaced relay for good measure, didn't make a difference. Which fuse is it under the dash? None of my fuse diagrams are very helpful identifying it. Fuel filter is clean and not clogged. The fuel pump relay clicks when I turn the key, did it with the old relay and the new, can't figure out why.

3 people found this helpful.
40

I'm having same problem on a 1990 1.6. Did a diagnostic flash code, got code 1, ignition pulse. Relating to coils, ignitor and wiring. Coils are six month old, put a brand new ignitor on. Still won't run. Starts and runs for one second, then dies. Will run on easy start spray.

4 people found this helpful.
10

Hi, mine starts and runs fine for the first 15 mins then relay starts clicking and car idles badly. Tried a brand new relay and nothing changed

1 people found this helpful.

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