Non-starting N/A
Discussion
Bought a very, very cheap non-starting NA to mess around with. Bought sight unseen and now it's here I can see it's not in good shape at all so not sure on the long term viability of this car but I would like to get it running and MOT'd and make a decision from there.
It's 91 Eunos 1.6.
It turns over just fine but no spark if I hold plug 1 against the cam cover.
I've replaced the CAS with a good used one.
The timing belt is intact.
I've removed an old immobiliser. I couldn't tell if it was doing anything or not but it had a red light fitted that would never go off so I removed the whole immobiliser and repaired the factory ignition switch cables.
After doing that, I now see the battery and brakes red lights on the dash with the ignition on which I didn't before so I think the immobiliser was bust but unfortunately I still have a non-starting car.
To check the fuel pump works, I used the jumper in the diagnostics port and that fires up just fine. I don't hear it prime upon turning the ignition on but I believe that doesn't happen on 1.6 cars.
On the fuel side again, I noticed that the car didn't smell of petrol after cranking and that plugs seemed dry. I removed the hose from the fuel supply hard line and tried cranking. During cranking, nothing comes out but as I stop cranking, I get a tiny little glug of fuel popping out. Strange?
It's getting trickier now to check things as I'm generally working on my own and difficult to check for voltages while turning the key. But I think I need to come up with a more methodical plan rather than just jumping from one thing to another.
So what's next?
It seems to me that during cranking the car is not trying to supply spark or fuel.
One thing I did notice was that when I turn the ignition key to on (but not start pos), all seems fine but if I turn it the slightest fraction past there, there is a dead spot where the ignition goes off and then you push through that and the starter cranks. It made me wonder if it could be an ignition switch issue where only the starter itself is energised during cranking.
It's 91 Eunos 1.6.
It turns over just fine but no spark if I hold plug 1 against the cam cover.
I've replaced the CAS with a good used one.
The timing belt is intact.
I've removed an old immobiliser. I couldn't tell if it was doing anything or not but it had a red light fitted that would never go off so I removed the whole immobiliser and repaired the factory ignition switch cables.
After doing that, I now see the battery and brakes red lights on the dash with the ignition on which I didn't before so I think the immobiliser was bust but unfortunately I still have a non-starting car.
To check the fuel pump works, I used the jumper in the diagnostics port and that fires up just fine. I don't hear it prime upon turning the ignition on but I believe that doesn't happen on 1.6 cars.
On the fuel side again, I noticed that the car didn't smell of petrol after cranking and that plugs seemed dry. I removed the hose from the fuel supply hard line and tried cranking. During cranking, nothing comes out but as I stop cranking, I get a tiny little glug of fuel popping out. Strange?
It's getting trickier now to check things as I'm generally working on my own and difficult to check for voltages while turning the key. But I think I need to come up with a more methodical plan rather than just jumping from one thing to another.
So what's next?
It seems to me that during cranking the car is not trying to supply spark or fuel.
One thing I did notice was that when I turn the ignition key to on (but not start pos), all seems fine but if I turn it the slightest fraction past there, there is a dead spot where the ignition goes off and then you push through that and the starter cranks. It made me wonder if it could be an ignition switch issue where only the starter itself is energised during cranking.
I would first pull the ecu and see if its covered in water, this is what i did when i originally picked up my non runner.
There is a fuse in the engne fusebox called room fuse, it can be found on these diagrams, i believe it powers the ecu, someone had removed mine.
From memory fuel pump control on these is via a switch in the afm.
https://www.miataforumz.com/how-40/mazda-miata-wir...
There is a fuse in the engne fusebox called room fuse, it can be found on these diagrams, i believe it powers the ecu, someone had removed mine.
From memory fuel pump control on these is via a switch in the afm.
https://www.miataforumz.com/how-40/mazda-miata-wir...
I think I may have isolated the problem. I cleaned all the ECU connectors and checked all fuses again but still no starting no spark or fuel. So i turned my attention to the CAS again even though I'd already replaced it. Since I had a spare CAS of unknown condition I thought I'd just plug that into the CAS plug on the loom and turn it by hand with the ignition on. Guess what, I got a spark! First time on this car. So I initially thought, I'd just taken out a working CAS and fitted a bad one so I swapped them over again and expected the car to erupt into life but no spark when I turn the starter.
So I think there are now only two possibilities here. The least likely one is that I have to bad CAS's and they both give a signal when turning at very low speed by hand but don't when turning at cranking speeds.
What I actually think is wrong is that when I turn the ignition switch past pos 2 to engage the starter, I think the ignition is going to off. So I think I have a bad switch. I'm going to try and work out how I can test that next.
Feels like I'm getting somewhere.
So I think there are now only two possibilities here. The least likely one is that I have to bad CAS's and they both give a signal when turning at very low speed by hand but don't when turning at cranking speeds.
What I actually think is wrong is that when I turn the ignition switch past pos 2 to engage the starter, I think the ignition is going to off. So I think I have a bad switch. I'm going to try and work out how I can test that next.
Feels like I'm getting somewhere.
And we have a runner!
I took the ignition barrel apart and cleaned everything. Initially I thought it had achieved nothing as still no start but I'd forgotten to plug the CAS back in. Once that was plugged in it fired instantly. 4 years since it last ran apparently.
There's a lot to do before I'll even go near an MOT centre but for now, I'm bloody ecstatic.
I took the ignition barrel apart and cleaned everything. Initially I thought it had achieved nothing as still no start but I'd forgotten to plug the CAS back in. Once that was plugged in it fired instantly. 4 years since it last ran apparently.
There's a lot to do before I'll even go near an MOT centre but for now, I'm bloody ecstatic.
Belle427 said:
well done, great result.
Thanks. Really appreciated your input. Helped narrow things down a lot and I'm glad I looked at the ECU as that area was very brown indeed. Look at this pic! Luckily nearly all the rust is on the brackets and cover plate so I'll just wire brush the floor and get some protection on there. I think I might need a new ECU cover plate though!
Amazingly the ECU itself is clean as a whistle.
Edited by Gad-Westy on Friday 27th October 09:01
Belle427 said:
I left the plate out of mine and tucked the ecu up under the dash out of harms way.
A couple of cable ties was all it needed.
Cheers. It might be a good option as the studs that hold the bracket to the floor are quite crusty and I'm not confident that I'm going to get the nuts of the without resorting to the dremel. They're drenched in Plug Gas as we speak. A couple of cable ties was all it needed.
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