HELP PLEASE 2003 miata ecu issues
09-22-2023, 05:13 PM
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HELP PLEASE 2003 miata ecu issues
hi sorry if any of my formatting is wrong this is my first ever forum post.
i have a 2003 nb2 and after i did my timing belt i was having issues getting the car to start, timing was set properly but no fuel pump and no spark. during this time we also had the immob light flashing(2 long flashes 4 short flashes, immob is not communicating with the pcm). we decide to replace the ecu with a standalone, because the obd was also not reading so it seemed like a reasonable thing to replace, i went with a MEITE me442 to see if that will get the car to start, it does, however THE KEY DOES NOT TURN THE CAR OFF, and with the immob box plugged in it still flashes we turned it off by disconnecting spark plugs or stalling and then disconnect the battery. car runs for a week essentially long enough for it to be properly street tuned. and then one day im driving and the battery starts turning off and back on i think this is the ecu doing auto tune and ltt tuning, i get to a light and the battery dies again, does not turn back on, car is cranking no spark and no fuel. the miat is currently at mazda who says it needs a new pcm. ANY AT ALL PLACES TO START WOULD HELP SO MUCH car broke down 1000 miles from home 😭😭 if anyone is located near the chicagoland area wants to come give it a look dm me please 👍👍
i have a 2003 nb2 and after i did my timing belt i was having issues getting the car to start, timing was set properly but no fuel pump and no spark. during this time we also had the immob light flashing(2 long flashes 4 short flashes, immob is not communicating with the pcm). we decide to replace the ecu with a standalone, because the obd was also not reading so it seemed like a reasonable thing to replace, i went with a MEITE me442 to see if that will get the car to start, it does, however THE KEY DOES NOT TURN THE CAR OFF, and with the immob box plugged in it still flashes we turned it off by disconnecting spark plugs or stalling and then disconnect the battery. car runs for a week essentially long enough for it to be properly street tuned. and then one day im driving and the battery starts turning off and back on i think this is the ecu doing auto tune and ltt tuning, i get to a light and the battery dies again, does not turn back on, car is cranking no spark and no fuel. the miat is currently at mazda who says it needs a new pcm. ANY AT ALL PLACES TO START WOULD HELP SO MUCH car broke down 1000 miles from home 😭😭 if anyone is located near the chicagoland area wants to come give it a look dm me please 👍👍
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09-22-2023, 06:19 PM
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Of course Mazda will say it needs a new ECU because it doesn't have the stocker. Generally, dealers are not the best place to take a non-standard car, especially cars with engine problems running on a weird (to them) engine management system.
Sounds like a proper fustercluck to me. I can't make heads or tails out of your description. First, you need to get the car back where you can work on it. Then you need to find someone trustworthy/knowledgeable to look at it, someone who is comfortable with modified cars, preferably modified MX5s.
To help us:
How long have you had the car? Other than the ECU and timing belt, what else have you worked on? What do you know of the car's history before you? What mods does the car have? Pictures of the engine bay. You say timing was set correctly, what exactly did you do to the timing?
As a WAG, you might have screwed up the cam timing doing the timing belt, and it is dieseling - check the cam timing CAREFULLY. If that doesn't work, plug the OEM ECU in, check the timing again, and see if that works (you may have screwed up the settings in the ME ECU).
Some basics: on a stock unmolested car, ECU replacement is rare to nonexistent. Don't make a change in the hope 'that might fix it' - make a change when you know or have good grounds to believe what you are changing is (part of) the problem.
This is public board, where posters interact or just learn from others, save the DMs for FB,
Playing with cars is such fun isn't it?!
Sounds like a proper fustercluck to me. I can't make heads or tails out of your description. First, you need to get the car back where you can work on it. Then you need to find someone trustworthy/knowledgeable to look at it, someone who is comfortable with modified cars, preferably modified MX5s.
To help us:
How long have you had the car? Other than the ECU and timing belt, what else have you worked on? What do you know of the car's history before you? What mods does the car have? Pictures of the engine bay. You say timing was set correctly, what exactly did you do to the timing?
As a WAG, you might have screwed up the cam timing doing the timing belt, and it is dieseling - check the cam timing CAREFULLY. If that doesn't work, plug the OEM ECU in, check the timing again, and see if that works (you may have screwed up the settings in the ME ECU).
Some basics: on a stock unmolested car, ECU replacement is rare to nonexistent. Don't make a change in the hope 'that might fix it' - make a change when you know or have good grounds to believe what you are changing is (part of) the problem.
This is public board, where posters interact or just learn from others, save the DMs for FB,
Playing with cars is such fun isn't it?!
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09-22-2023, 07:16 PM
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Of course Mazda will say it needs a new ECU because it doesn't have the stocker. Generally, dealers are not the best place to take a non-standard car, especially cars with engine problems running on a weird (to them) engine management system.
Sounds like a proper fustercluck to me. I can't make heads or tails out of your description. First, you need to get the car back where you can work on it. Then you need to find someone trustworthy/knowledgeable to look at it, someone who is comfortable with modified cars, preferably modified MX5s.
To help us:
How long have you had the car? Other than the ECU and timing belt, what else have you worked on? What do you know of the car's history before you? What mods does the car have? Pictures of the engine bay. You say timing was set correctly, what exactly did you do to the timing?
As a WAG, you might have screwed up the cam timing doing the timing belt, and it is dieseling - check the cam timing CAREFULLY. If that doesn't work, plug the OEM ECU in, check the timing again, and see if that works (you may have screwed up the settings in the ME ECU).
Some basics: on a stock unmolested car, ECU replacement is rare to nonexistent. Don't make a change in the hope 'that might fix it' - make a change when you know or have good grounds to believe what you are changing is (part of) the problem.
This is public board, where posters interact or just learn from others, save the DMs for FB,
Playing with cars is such fun isn't it?!
Sounds like a proper fustercluck to me. I can't make heads or tails out of your description. First, you need to get the car back where you can work on it. Then you need to find someone trustworthy/knowledgeable to look at it, someone who is comfortable with modified cars, preferably modified MX5s.
To help us:
How long have you had the car? Other than the ECU and timing belt, what else have you worked on? What do you know of the car's history before you? What mods does the car have? Pictures of the engine bay. You say timing was set correctly, what exactly did you do to the timing?
As a WAG, you might have screwed up the cam timing doing the timing belt, and it is dieseling - check the cam timing CAREFULLY. If that doesn't work, plug the OEM ECU in, check the timing again, and see if that works (you may have screwed up the settings in the ME ECU).
Some basics: on a stock unmolested car, ECU replacement is rare to nonexistent. Don't make a change in the hope 'that might fix it' - make a change when you know or have good grounds to believe what you are changing is (part of) the problem.
This is public board, where posters interact or just learn from others, save the DMs for FB,
Playing with cars is such fun isn't it?!
playing with cars got me on the verge of a stroke i am a wee lad to be doing all this electrical ****😭
have had the car for 2 years in order IVE done brakes coils sway bars so not very technically adept but i still felt confident to do the timing
the car was 100% bone stock southern kept reasonably maintained nb2 miata
for setting the timing we forgot to disconnect the battery first of all, past that we did in fact **** it up like 4 times but then we got it i set the exhaust cam exactly as carpassionchannel shows in his vid(crank is at tdc i checked more times than i can count) then i had my friend hold a adjustable wrench on the intake cam while i slipped the belt on, from there we did the proper tightening procedure.
my thinking with replacing the stock ecu with a standalone is i believed the immobilizer was stopping my car from starting and a standalone would not care about the immobilizer at all
the other guy said pinched wires and such, 1 i do not know how to check such things, 2 car was running fine(if a little rich which we tuned out) for a week
you said get it out of mazda and to an expert, the only expert in my area is mazda 😭😭 i really fucked up yall i love my car too much be ****** up this bad
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09-22-2023, 07:35 PM
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is there possibly a diag or a picture of the locations i should be checking, and when checking grounds i use a multimeter set to volts and am looking for 0 volts corrext? as i said i have very little experience in the electronics field which is why its at mazda
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09-22-2023, 07:59 PM
#6
A search on google for nb miata grounds will probably find you pics of where to look.
But the ones that come to mind, there's on on the driver side by the exhaust manifold, that goes from the body to the flex plate. And one just above the throttle body on the intake manifold with a 10mm bolt, that's an ecu ground so if it's loose it probably wouldn't run or could be very bad. There are grounds under the headlights on both sides. Probably one on the back of the head, don't remember.
Multimeter on ohms. If you touch the leads to each other, it should show 0 ohms or something very low like 0.8 ohms. Some have a beep mode and it will beep when you touch them together which makes it each to check continuity between points. All grounds should beep when touched to engine head/block or chassis.
But the ones that come to mind, there's on on the driver side by the exhaust manifold, that goes from the body to the flex plate. And one just above the throttle body on the intake manifold with a 10mm bolt, that's an ecu ground so if it's loose it probably wouldn't run or could be very bad. There are grounds under the headlights on both sides. Probably one on the back of the head, don't remember.
Multimeter on ohms. If you touch the leads to each other, it should show 0 ohms or something very low like 0.8 ohms. Some have a beep mode and it will beep when you touch them together which makes it each to check continuity between points. All grounds should beep when touched to engine head/block or chassis.
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09-22-2023, 08:03 PM
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Heads up mate, learn how to search. This cost me 20 miniutes of my life that I am never going to get back. Go to post 59, where you will find that an esteemed poster whose memory is now fading had helped another with similar problem.
Lets try to avoid repeating here the avoidable drama of that thread - do this and report back. If it works, I want my dollar.
Lets try to avoid repeating here the avoidable drama of that thread - do this and report back. If it works, I want my dollar.
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09-22-2023, 08:17 PM
#8
Heads up mate, learn how to search. This cost me 20 miniutes of my life that I am never going to get back. Go to post 59, where you will find that an esteemed poster whose memory is now fading had helped another with similar problem.
Lets try to avoid repeating here the avoidable drama of that thread - do this and report back. If it works, I want my dollar.
Lets try to avoid repeating here the avoidable drama of that thread - do this and report back. If it works, I want my dollar.
I didn't know what you meant or that it was directed at me, but I read that old thread, then saw my post and that it fixed his car, then it all came together....
Good stuff! That was 8 years ago, I had totally forgotten about that.
Yeah, to OP, try doing what I mentioend in that thread, it's worked for someone in the past!
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09-22-2023, 11:58 PM
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HAHAHAHAHAHAHAHAHAHAHA
I didn't know what you meant or that it was directed at me, but I read that old thread, then saw my post and that it fixed his car, then it all came together....
Good stuff! That was 8 years ago, I had totally forgotten about that.
Yeah, to OP, try doing what I mentioend in that thread, it's worked for someone in the past!
I didn't know what you meant or that it was directed at me, but I read that old thread, then saw my post and that it fixed his car, then it all came together....
Good stuff! That was 8 years ago, I had totally forgotten about that.
Yeah, to OP, try doing what I mentioend in that thread, it's worked for someone in the past!
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09-23-2023, 01:17 AM
#10
I doubt the VVT actuator is bad. If in doubt, unplug it and it will go to full retarded position. THe car will run fine with it unplugged, so easy to rule that out. My post in the other thread was about CAM TIMING, not the vvt actuator itself.
In fact, you only need a few sensors for it to run decently. MAF, CRANK, CAM for sure, maybe TPS, the rest it will run without.
I hope you can fix it quick. Miata's are simple cars.
If it were me, I'd put the stock ECU back in, charge battery, get a camera going and film what's happening and upload the high res, clear audio video here to help with diagnostics.
In fact, you only need a few sensors for it to run decently. MAF, CRANK, CAM for sure, maybe TPS, the rest it will run without.
I hope you can fix it quick. Miata's are simple cars.
If it were me, I'd put the stock ECU back in, charge battery, get a camera going and film what's happening and upload the high res, clear audio video here to help with diagnostics.
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09-23-2023, 12:06 PM
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I doubt the VVT actuator is bad. If in doubt, unplug it and it will go to full retarded position. THe car will run fine with it unplugged, so easy to rule that out. My post in the other thread was about CAM TIMING, not the vvt actuator itself.
In fact, you only need a few sensors for it to run decently. MAF, CRANK, CAM for sure, maybe TPS, the rest it will run without.
I hope you can fix it quick. Miata's are simple cars.
If it were me, I'd put the stock ECU back in, charge battery, get a camera going and film what's happening and upload the high res, clear audio video here to help with diagnostics.
In fact, you only need a few sensors for it to run decently. MAF, CRANK, CAM for sure, maybe TPS, the rest it will run without.
I hope you can fix it quick. Miata's are simple cars.
If it were me, I'd put the stock ECU back in, charge battery, get a camera going and film what's happening and upload the high res, clear audio video here to help with diagnostics.
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09-23-2023, 12:27 PM
#12
It make sense to start with the fundamentals and document what is right. For example, checking fuel pressure, ignition for spark, compression test would tell you a lot. An engine needs 3 things to run, fuel, spark, compression. Those 3 things, it runs. If it's not running, you're not getting one or two or three of those things.
If it has spark and compression, it will bust off and run on carb spray or starting fluid.
if it has fuel, the spark plugs will smell like gasoline and be slightly wet.
If it doesn't have enough compression after a timing belt job, cam timing is very likely the issue.
If it has spark and compression, it will bust off and run on carb spray or starting fluid.
if it has fuel, the spark plugs will smell like gasoline and be slightly wet.
If it doesn't have enough compression after a timing belt job, cam timing is very likely the issue.
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09-23-2023, 07:10 PM
#13
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It make sense to start with the fundamentals and document what is right. For example, checking fuel pressure, ignition for spark, compression test would tell you a lot. An engine needs 3 things to run, fuel, spark, compression. Those 3 things, it runs. If it's not running, you're not getting one or two or three of those things.
If it has spark and compression, it will bust off and run on carb spray or starting fluid.
if it has fuel, the spark plugs will smell like gasoline and be slightly wet.
If it doesn't have enough compression after a timing belt job, cam timing is very likely the issue.
If it has spark and compression, it will bust off and run on carb spray or starting fluid.
if it has fuel, the spark plugs will smell like gasoline and be slightly wet.
If it doesn't have enough compression after a timing belt job, cam timing is very likely the issue.
stock ecu
error: pcm is not picking up power, its there but pcm isnt turning on
cranks no spark no fuel pump
put in standalone
starts
one week
error pcm is not picking up power its there but pcm is not turning on(further proved by laptop not connecting to standalone)
cranks no spark no fuel pump
my fear is running around in circles chasing a mechanical problem when its seeming to be a electrical or computer one. stranded in illinois with not much money and if i ask my parents to buy something id like to be sure itll fix it (when troubleshooting on the stock ecu we tried just about everything, new sensors, had a spec miata driver check the timing, check the fuses, check the timing, check the fuel pump, check the fuses again, check the timing again) this rabbit hole of “fixing these problems” was only getting deeper and deeper as my wallet got more and more shallow. at this point every sensor other than the maf and tps is new( out of the list of neccesary sensors to start) mazda checked all the fuses and relays says theyre fine. however i will check out these grounds myself and make sure theyre all there or however it works
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09-23-2023, 07:16 PM
#14
to clarify because my posts are long and whimsical this is exactly what ive been told the problem is
stock ecu
error: pcm is not picking up power, its there but pcm isnt turning on
cranks no spark no fuel pump
put in standalone
starts
one week
error pcm is not picking up power its there but pcm is not turning on(further proved by laptop not connecting to standalone)
cranks no spark no fuel pump
my fear is running around in circles chasing a mechanical problem when its seeming to be a electrical or computer one. stranded in illinois with not much money and if i ask my parents to buy something id like to be sure itll fix it (when troubleshooting on the stock ecu we tried just about everything, new sensors, had a spec miata driver check the timing, check the fuses, check the timing, check the fuel pump, check the fuses again, check the timing again) this rabbit hole of “fixing these problems” was only getting deeper and deeper as my wallet got more and more shallow. at this point every sensor other than the maf and tps is new( out of the list of neccesary sensors to start) mazda checked all the fuses and relays says theyre fine. however i will check out these grounds myself and make sure theyre all there or however it works
stock ecu
error: pcm is not picking up power, its there but pcm isnt turning on
cranks no spark no fuel pump
put in standalone
starts
one week
error pcm is not picking up power its there but pcm is not turning on(further proved by laptop not connecting to standalone)
cranks no spark no fuel pump
my fear is running around in circles chasing a mechanical problem when its seeming to be a electrical or computer one. stranded in illinois with not much money and if i ask my parents to buy something id like to be sure itll fix it (when troubleshooting on the stock ecu we tried just about everything, new sensors, had a spec miata driver check the timing, check the fuses, check the timing, check the fuel pump, check the fuses again, check the timing again) this rabbit hole of “fixing these problems” was only getting deeper and deeper as my wallet got more and more shallow. at this point every sensor other than the maf and tps is new( out of the list of neccesary sensors to start) mazda checked all the fuses and relays says theyre fine. however i will check out these grounds myself and make sure theyre all there or however it works
That said, I'd get a multi meter (20 bucks at walmart) and start taking measurements. Likely there is only 1 problem, so no way I'd replace a lot of parts trying to guess what the problem is.
A multimeter allows you to measure voltage or continuity to diagnose precisely what is wrong. Then fix it.
This is the cheapest possible way to solve it.
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