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MX5 MK1 Eunos 1.6 Non-Starter - Guidance Is Needed!
Big T - 9/6/22 at 06:06 PM

Hello MX5 Nutz,

I am hoping this is in the correct place, i will try and include as much information as possible in an attempt to help locate the problem.

The car is a 1989 import 1.6 model. The car has been off of the road for around 9 years looking at the MOT history. The car is wanted as a donor vehicle and i want to confirm it as running prior to stripping it down.

The Non-Starting details are as follows

There is no fuel and no spark.

The dash lights up as it should and the engine has a strong crank.

The igniter module on the drivers side inner wing is getting a 12v feed coming into it.

There is no spark at all at the plugs.

There is no sound of a priming fuel pump, even if the port in the engine bay is bridged, however i think i can hear the relay clicking.

My Conclusion

I suspect that the fuel supply problem is related to the fuel pump, For now this isn't a huge concern as i can manually prime the engine with fuel. Regarding the spark, i am a bit more stumped. My initial thoughts are that the CAS is at fault. Can anyone tell me is there is a resistance test i can run with the engine cranking to try and narrow down the faulty component? I understand that a replacement part will be the most efficient way to pin point the problem, however i would rather do a bit more research rather than just throwing money at it and hoping for the best.

Is there any tests i can do to help pin point the problem?

Any input, suggestions or help would be hugely appreciated!


gremlin1234 - 9/6/22 at 06:50 PM

for the no fuel issue the first thing I would try would usually be eazystart (basically spray fuel into the air intake) for the spark it could be anything, but as always check the earths on engine, coil, ecu, alternator, and even the battery!


gary gsx - 9/6/22 at 07:06 PM

Have you checked crankshaft sensor I believe that fires fuel pump and coil pack’s. Has it got a diagnostic plug I’m sure you can bridge a wire across to get pump running or it maybe only the mark 2


theconrodkid - 9/6/22 at 08:58 PM

sounds like you have more than one problem, the pump should prime for a couple of seconds, maybe the pump has seized or dodgy fuse / relay ?, give the pump a thump
re no spark, most likley the cam / crank angle sensor, without that sending a signal there will be no sparks and the injection wont know when to fire so so squirt
have you got have an imobiliser ?


Jaymaxi - 10/6/22 at 09:23 AM

Second the imobiliser, a couple over here had aftermarket imobilisers fitted, seemed to run the pump and spark, usually something on the key to plug in,or a hidden switch, might be of no help but maybe worth a look, the Eunos electrics were pretty robust, John


RedAvon - 10/6/22 at 04:07 PM

I had the same issue on my Mk2, traced every wire to ignition, fuel pump, ecu, immobiliser, etc, etc.

Changed the cam sensor.

The crank sensor looked ok. However, when I checked it again, someone had used a threaded bolt rather than shoulder bolt and it had worn slightly loose, so that the rotating flange rubbed into the magnet housing.

The fuel pump relay was clicking as yours is.

It would be worth checking the gap is correct for the crank case sensor and that your getting a signal/pulse as this seems to shut everything down.

No error codes showed up either.

Hope that helps.
Ian


indykid - 10/6/22 at 06:40 PM

The mk1 engine doesn't have a crank sensor, only a cam angle sensor.

Have you checked for voltage at the pump connector under the rear deck carpet when you bridge the diagnostic connector? Easiest test for a dead pump, but if it has power, pull it out of the tank to check the internal connections before you source another one.


RedAvon - 10/6/22 at 07:57 PM

Ahh, I didn't know that, apologies.

Ian


pewe - 11/6/22 at 03:04 PM

Besides all the above suggestions I would look at the in-tank filter below the pump.
If it's been stood for so long not impossible the fuel has evaporated leaving gunge.
Also fuel filter under left side wheel arch worth checking for flow.
No spark can equal failed coil pack.
If you need alternative suggestions look at Mighty5's or MX5 Nutz (public service advice, admins).