- My model of MX-5 is: 97 1.8
- I’m based near: Wolverhamtpon
- I’m looking for technical help or recommendations on: Stalling engine
I have been having this problem for some time now, ever since I tried st start my car again after it sat over winter, it just won’t run. It starts fine idles steady and after a few seconds just cuts out, no sputter and then cutting, just straight cuts out. For context the only part that was changed through winter is a new alternator. I have tried many things to try and get it to start which I will list below:
• Vacuum leak test
• Changed fuel pump
• Checked fuel relay (bridging gnd and fp in diag box)
• Checked for codes (bridging gnd and 10 in diag box)
• Checked for Spark
• Unplugged MAF no change
• Tried different MAF no change
l’ve tried all of these things and still exactly the same as before. I’m pretty lost on what it could be at this point, my only thought is since it just cuts out, the ecu is telling the car to do so? Which means it could be immobilster? (My car has OEM immobiliser) Which I have no idea how to fix if that is the case.
Any help on this would be greatly appreciated.
How does the immobiliser light behave? When does it come on, how long does it stay on for and when does it go off. Does it cut out consistently at the same time once the engine has started?
There us no light on the dash, i just assumed it would be the immobilizer to be honest, and yes every time it cuts out its at the exact same time and revs
Does the immobiliser light not come on when you turn the ignition on or start the engine?
How full was the tank when it was stored? Fuel goes off after about 3 months especially if the tank wasn’t full. This is because the volatile components of the fuel can oxidise with the air in the tank. Also condensation in the tank can cause rust that can block the fuel filter. Fill up with premium fuel and change the filter too. Hope this helps.
was about 1/4 full, when i changed the duel pump i did notice the fuel had a yellowish/orange tinge
No light, i didnt know there was one to be honest
Sorry for long reply, yes its a UK MX-5. Heres a video of what happens. Watch IMG_1514 | Streamable
Immobiliser light is lifeless which is odd. Are you sure that there are no fault codes stored. I’d certainly focus on why that light isn’t working at all first. Easier said than done though, I appreciate that. Have you got another key to try? And check all the fuses. If you post your VIN I’ll try and give you some pointers but it’ll be a long process…
Why was the alternator changed? Did it run immediately before this and immediately after?
Hi, sorry for the late response I’ve been doing much research. I do 100% believe it is the immobiliser now, I didn’t say before but I definitely should have mentioned it, the previous owner did a dashboard cut, and turned the switches such as hazard and fog light switch into flip switches. I saw that this may affect the immobiliser? I will attach photo of said switches. I also did the code read as you said to do, video here Watch unnamed | Streamable . Not sure what any of it means but I hope it helps. Also replaced all the fuses in engine bay fuse box as they were all corroded including main fuse but that changed nothing.
Also to answer alternator question, the previous alternator was seized and it was not running before.
Also VIN is JMZNA18P200310120
From that video I reckon that you’ve got
P0100 - Mass Air Flow Sensor
P0110 - Air intake Temperature Sensor
P0443 - Purge Solenoid Valve
P1402 - EGR Valve Position Sensor
P1602 - immobiliser Unit Communication Error
I’m guessing that the first 4 codes have been induced by your previous diagnosis. Check that all of those things are plugged in, clear the codes (disconnect the negative battery cable and press the brake pedal for 20 seonds) and check that only P1602 remains. I wouldn’t mind a video of that too please. If so, possible causes are:
A fault in immobiliser unit to ECU communication line, check continuity along a blue wire from the ECU to the immobiliser unit and for a short to ground and short to live.
A faulty immobiliser unit.
A faulty ECU.
Those wiring repairs in your photos would fill me with dread though!
Hi again, thanks for the help, I did what you said i removed the negative from the battery and held the brake for 20 seconds. The video is here of the updated codes.
I ensured all plugs were fine which they are and all the wires also fine. I checked the blue wire and there is no damage but I’m yet to check the continuity of it.
Also regarding the wiring I read that if the wiring isn’t correct to the hazard light switch, it will prevent the car from a starting, in the same way as the immobiliser by cutting off the engine. Is this true? Because all the switches are wired differently as you saw.
From the video, you’ve still got:-
P0443
P1402
P1602
I can’t see that the first 2 would stop the engine starting but P1602 is most likely your problem. The fact the other 2 codes remain though does indicate other concerns, if everything is plugged in.
I’ve never heard of hazard switch wiring causing a non start, it is simply an orange wire from the flasher unit to the switch and a black wire to ground. I think that you’re getting confused with an 1993 Vauxhall Nova… oh no, sorry, they used to allow you to start the engine if you plugged the hazard switch in the wrong way up didn’t they?
I think P0433 and the P1402 codes make sense as the car has had a egr delete and a charcoal canister delete so they no longer exist.
How do I go about fixing P1602 then, is my only option to get a aftermarket ecu?
Also regarding the hazard light switch I just saw on some random forum his hazard light was unplugged and as soon as he plugged it back in it started up again haha. I was just clutching at straws
