Mazda MX-5 Miata banner
21 - 40 of 70 Posts

·
Registered
Joined
·
109 Posts
You can use the I/O tab in meite. My car wasn't starting as the fuel pump wasn't configured to the correct relay? Probably not helpful in your case as your map was working BUT you can verify things work using a test mode in the drop-down list.

E.g. find relay for the fuel pump or fan and switch to test mode and if configured correctly it should turn on.





Sent from my motorola one using Tapatalk
 

·
Hiding from the Ayatollah or making Full Metal Jac
Joined
·
1,653 Posts
on the NA the fuel pump is activated by the ignition system relay & fuel pump relay, not the ECU.
 

·
Happily expanding the To Do list since 1997
Joined
·
10,590 Posts
on the NA the fuel pump is activated by the ignition system relay & fuel pump relay, not the ECU.
1.6 and 1.8 are different.

On a '94 1.8 the fuel pump relay is driven by a light green wire from ECU pin 2T (which also goes to the Diagnostics port).
 

·
@Markbcars
Eunos Turbo
Joined
·
857 Posts
Discussion Starter · #25 ·
Hi Guys,

Spent some time poking around today..

Spark plug tester showed activity on each cylinder, that was odd as it stinks of fuel so really believed fuel was ok and if spark, should go bang.

anyway, removed plugs, all soaked in fuel. All pretty black, so have them a clean.

Tested coilpacks with meter, seemed in spec..

very confused now.

Put 3 spark plugs back but left one out to arc it off the strut brace, bingo, spark was seriously weak and inconsistent. Also, found that the tester would illuminate when the spark plug wasn’t. So
I’m going to get myself a new coilpack.

just before I do, is it worth going to COP? I don’t plan on upping the cars power at all and I’ve never experienced an issue with my current setup but if COP conversion can add something like more response and works with my gen1 me221, I’ll give it a go.

cheers
 

·
Registered
Joined
·
1,059 Posts
If there is too much fuel it won’t fire either, you may have just flooded the engine. Dry all the plugs, leave them out overnight to let any excess in the cylinders evaporate, then put the plugs back in and try again. Don’t touch the throttle..
 

·
@Markbcars
Eunos Turbo
Joined
·
857 Posts
Discussion Starter · #27 ·
Thanks for all the info here guys..


Update...

Fitted new coilpack, no change, still won't fire up, seems to try and catch a bit more than it did before.

Engine is timed correctly, check TDC on cylinder one and marks on pulley line up. Unplug CAS, it doesn't try and catch at all, so that tells me the CAS is doing something. Getting fuel, smell it from the exhaust and all plugs are wet with fuel after cranking.

Kind of clueless now and worried the ME221 is possibly at fault. A mate said is the vacuum hose connected to it? I haven't checked but if not, would that stop the car firing up?

No idea what else to check now
 

·
Registered
VVT swapped NA & TD04 turbo NB
Joined
·
247 Posts
Kind of clueless now and worried the ME221 is possibly at fault. A mate said is the vacuum hose connected to it? I haven't checked but if not, would that stop the car firing up?
The vacuum hose is just reading absolute pressure which would be atmospheric pressure in both scenarios, I would imagine it would be reading the same as the engine is starting (before it's moving air) as if the hose was broken completely? My two cents anyways.

So just thinking this through:

  • You said spark was weak before changing coil pack, is it weak now?
  • Have you checked your main relay for damage?
  • Have you checked your crank sensor gap - credit card width? Might be worth swapping if you have a spare anywhere?
  • You can do a cranking check using the following procedure from MEITE:
  • Rectangle Slope Font Screenshot Parallel

The last check should show if your crank and cam sensor are working and syncing properly.
 

·
@Markbcars
Eunos Turbo
Joined
·
857 Posts
Discussion Starter · #29 ·
Cheers mate,

Checked the vac pipe, all good, no issues there.

New plugs still weak, my leads are 3 year old original spec, I'm sure they're fine but tempted to just get better new ones. New plugs arrived but not tried anything with these yet.

Relays look good to me, main fuel inj clicks, all others in place and no signs of an issue

Mk1 crank sensor is in the cas so no clearance

Took some screens shots of meite, shows signals from cas...





I really don't know what the issue could be now!

Why would I be getting a weak spark?! it would be weird for plugs/leads to be so fried that the car wouldnt fire, coils are new, what comes before them, ECU or straight from CAS?

Earths are good. ahhhh i dunno
 

·
Registered
Joined
·
1,059 Posts
You haven’t left your ignition turned on whilst not running have you, that will soon fry your coils.
 

·
Happily expanding the To Do list since 1997
Joined
·
10,590 Posts
You haven’t left your ignition turned on whilst not running have you, that will soon fry your coils.
I wasn't aware that was a concern with ECUs except for the stock '94-'95 ECU (which had a bug that caused it to power up with the coils randomly energised or not).
 

·
Registered
Joined
·
2,580 Posts
Have you verified a good 12v on the feed to the coilpack. Ecu fires negative trigger but if the sparks are weak suggesting the 12v is poor lo voltage or when underload voltage drop Possible cable wire burnt out or bad connection.

Sent from my SM-N950F using Tapatalk
 

·
Registered
Joined
·
1,059 Posts
I wasn't aware that was a concern with ECUs except for the stock '94-'95 ECU (which had a bug that caused it to power up with the coils randomly energised or not).
I thought it was a concern with earlier ECU’s as well, and as a result always unplugged my ignition amplifier even after I had installed my MS2, Better safe than sorry
 

·
Registered
VVT swapped NA & TD04 turbo NB
Joined
·
247 Posts
You are getting lost sync on cranking? Correct me if I am wrong but I don't think that is spark related. More like faulty crank sensor etc

From the manual:

If the Lost Sync continues to count up, or the RPM intermittently displays, then goes back to zero, then you potentially have noise in the crank/cam sensor wiring - ensure it is shielded at the ECU end only on the wire-in versions, and that the wiring is in good condition on PnP models of the ME221. You can also try enabling filtering on the inputs (Suitable only for 36-1 or 60-2 triggers) in the Engine Driver to clean up electrical noise.

Another test is to make sure you’re triggering on the right ‘edge’ (the same as swapping the two wires leading to a crank/cam sensor on older ECUs). Change the trigger edges in the Engine Driver as a test. Note again that basemaps have these set correctly if using our PnP ECUs or Wiring Looms.

Once you have a stable RPM when cranking, and the ‘Sync Status’ DRO reads FULL, you are now ready to carry out the next step, timing the ignition.

Remember that changing edges or cam/crankshaft types and settings require a power reset for the changes to take effect.
 

·
@Markbcars
Eunos Turbo
Joined
·
857 Posts
Discussion Starter · #35 ·
Cheers all, thanks for tuning in to try and help..

Ignition not left on, well, nothing out of the normal but certainly not between it's last drive and the failed start... New coils now anyway.

12v feed is spot on..

Lost syncs, that's blowing my mind a bit but during those tests, my battery booster was dying so cranking wasn't the best, if that makes a difference? I'm getting to the point of wanting to buy another CAS, just because but having 2, I imagine 1 is ok.

I have just been out again, tested voltage to coils, plugs and engine earths, all good.

Used a 12v LED on injector plugs, each illuminated it as bright as each other.
Performed test again but connected to the injectors, each clicked on and off fine.
Fuel pump runs and sounds healthy, can hear it flowing through the rail.

Spark, tested with new plug, spark looks weak but I'm now doubting if this is actually normal.

So now, I really am just at a dead end over something that should be bloody simple.

My plugs get wet, after removing and drying them, so I believe the injectors are firing fuel ok.
I am getting a spark
Fuel pump works (assuming it's running while cranking)
CAS shows life on MEITI, unplugging it, stops spark, plugging it back it, spark returns
New coil pack fitted now.
New spark plugs but not fitted.

I haven't pulled injectors to see them actually spraying during crank
I haven't done a compression test

If 1 of the 2 sensors in the CAS sensor was failing, would I still get spark?

I'm just clueless now
 

·
@Markbcars
Eunos Turbo
Joined
·
857 Posts
Discussion Starter · #39 · (Edited)
Hi Zed, May take you up on that.. yet to get around to a compression test but thinking that’s my next step.

taking note of points mentioned, I tried a base map and an earlier map, no change, so returned back to my proper map.
Checked everythinggggg in terms of timing, plugs, leads, coils, CAS plug, all as they should be. Crank timing mark lines up with cylinder 1 TDC.
A friend was squirting easy start fluid into the throttle body and it still wasnt firing but not sure how well that stuff works

so next is compression test, if that checks out (I’m fearing the worst which would be really strange if it is a compression issue) then want to check fuel pressure, maybe injectors spray a bit of fuel and then just flop. Will cross that bridge after the comp test, wish me luck!

off topic, want to get a permanently fitted fuel pressure gauge, anyone done this while keeping the original FPR?

Cheers
 

·
Registered
Joined
·
2,580 Posts
Sytec do a test gauge. Ive used it in past. Inline fuel hose adaptor and tees off with a nylon capilairy hose that comes with about a metre so you can run into cabin and see pressure... its only for test purposes mind. Worked a treat.

You got a good ground on ecu ? Or more importantly the ground pin used for triggering. Just summit else to check. Need the ecu pinout for your model to ensure right pin and good ground.

Sent from my SM-N950F using Tapatalk
 
21 - 40 of 70 Posts
Top