|
|
Post by R2S on Oct 27, 2019 9:00:00 GMT
Does it keep running if you keep revs up and die when you take foot of accel? Or does it just die irrespective of throttle position?
|
|
|
|
Post by doubletrouble on Oct 27, 2019 10:08:09 GMT
Does it keep running if you keep revs up and die when you take foot of accel? Or does it just die irrespective of throttle position? Hi there. See video at beginning of thread. It will start up and idle for a couple of seconds. You can rev ut to 5k with throttle. When it cuts out it does not matter what you do with throttle and it does not try to fire. It is like the ignition or fuel just cuts dead. The fuel pump runs on so my thought is ignition but im not sure. |
|
|
|
Post by R2S on Oct 27, 2019 10:51:22 GMT
Ok its different to problem I had then, mine would start but wouldn't idle and it was as someone else has suggested earlier part of the crank case ventilation and vacuum pipework, I'd left a couple of pipes, including vacuum pipe to servo, undone not realising one of the many sensors needed the circuit closing.
Sorry I can't help.
Stating the obvious I know but it does sound like a sensor somewhere shutting things down, presume you've posted same question on MX5 forums?
|
|
|
|
Post by Stiggy on Oct 27, 2019 11:48:50 GMT
Let's assume the car ran correctly when it was an MX5. It is always strongly advised that all aspects of the donor are checked before stripping begins, it can be difficult to find the cause of a fault if you are not sure if you may have created issues during transplanting components or if the fault was there before.
Some of the possible causes of this run/cut issue are:
1. Earth's are the obvious potential mistake when installing the donor loom, there are several earth points as listed in the build guide and all must be connected.
2. Run and cut out issues differ on models, 1.6 have a flap in the air flow meter that keeps the engine running once air flows.1.8 engines may be worth a check with AFM disconnected to see if symptoms change, if they do change then it may be safe to assume there is no fault here.
3. TPS (throttle position sensor) maybe the issue, if it's not connected then the ECU will not be happy if you increase fuel. Again try with the TPS disconnected, if nothing changes it maybe this is the issue.
4. CPS (crank position sensor) can get damaged if engine is removed, you should be able to see if the engine has been out to paint the subframe. Is the sensor covered in cack? If not, try unplugging it, the engine probably wont run at all without it.
5. CAS (cam angle sensor) try without this plugged in to see if anything changes on the basis that if nothing changes then it maybe the culprit.
6.Try stabbing the throttle rapidly to keep it running if you sure the fuel pump is still running when the engine has cut out. The ECU powers the pump to surge on start up and will cut if it's not happy.
7. The run/cut are similar symptoms to the key reader not seeing correct key which suggests the imob is cutting to stop theft.
8. Unlikely but fuel filter may not let enough fuel through to keep it running if if it's partially blocked. Switch off, pressure drops, crap falls out of filter and then it will start up again.
9. Coil pack is probably OK if it runs for a few seconds normally.
10. Diagnostics, maybe a fault code has cropped up.
|
|
|
|
Post by doubletrouble on Oct 27, 2019 23:38:22 GMT
Let's assume the car ran correctly when it was an MX5. It is always strongly advised that all aspects of the donor are checked before stripping begins, it can be difficult to find the cause of a fault if you are not sure if you may have created issues during transplanting components or if the fault was there before. Some of the possible causes of this run/cut issue are: 1. Earth's are the obvious potential mistake when installing the donor loom, there are several earth points as listed in the build guide and all must be connected. 2. Run and cut out issues differ on models, 1.6 have a flap in the air flow meter that keeps the engine running once air flows.1.8 engines may be worth a check with AFM disconnected to see if symptoms change, if they do change then it may be safe to assume there is no fault here. 3. TPS (throttle position sensor) maybe the issue, if it's not connected then the ECU will not be happy if you increase fuel. Again try with the TPS disconnected, if nothing changes it maybe this is the issue. 4. CPS (crank position sensor) can get damaged if engine is removed, you should be able to see if the engine has been out to paint the subframe. Is the sensor covered in cack? If not, try unplugging it, the engine probably wont run at all without it. 5. CAS (cam angle sensor) try without this plugged in to see if anything changes on the basis that if nothing changes then it maybe the culprit. 6.Try stabbing the throttle rapidly to keep it running if you sure the fuel pump is still running when the engine has cut out. The ECU powers the pump to surge on start up and will cut if it's not happy. 7. The run/cut are similar symptoms to the key reader not seeing correct key which suggests the imob is cutting to stop theft. 8. Unlikely but fuel filter may not let enough fuel through to keep it running if if it's partially blocked. Switch off, pressure drops, crap falls out of filter and then it will start up again. 9. Coil pack is probably OK if it runs for a few seconds normally. 10. Diagnostics, maybe a fault code has cropped up. Hi Stuart. Thanks for the reply. I will check things out later this week. I jave already tried pulling the plug of the AFM and it made no difference. Same when i pull the plug on the little black immobiliser box, makes no difference. |
|
|
|
Post by davetherave on Oct 30, 2019 22:40:41 GMT
maybe ask on the uk Exocet facebook page might get more help on there when I had a electrical problem they helped me out and I got it working.
|
|
|
|
Post by morrin88 on Nov 4, 2019 17:12:22 GMT
I am no longer sure what it is. Tried another ECu and immobiliser set... same... unpluged immobiliser..... same.... unplug key sensor.... same.... gonna try another fuel pump i have and then swap out sensors one at a time.... would go for a third party ecu but unsure now... Whats the yeat and engine size of your donor? Maybe we can help each other out 😀 I’m a ‘94 mk1, 1.8 non immobiliser model. Today we’ve pulled the thing to bits, tested all the earths, the cam angle sensor, the ecu, maf, continuity between the points and the issue remains. There was an aftermarket immobiliser which was removed by the previous owner but the symptoms sound very similar with the engine starting and sounding ok for a few seconds then cutting off. Fuel & spark are OK. No block in the fuel lines, took the return off and it was happy to fill a bucket so fuel getting to the engine. Disconnected the cam sensor and it wouldn’t start at all, reconnected it and back to the original issue. Disconnected the air flow sensor and it still done the same thing, plenty suction on the intake. Multimeter down, cuppa and dinner. Exocet won the battle today, I’ll bloody win the war! |
|
|
|
Post by camspeed on Nov 5, 2019 9:22:49 GMT
On the basis you have tried just about everything I had a strange issue with a 1.8 doing something similar, ran for seconds and died.
I changed the alternator as that was the original fault and it ran perfectly afterwards.
Now I know it shouldn't make a difference as the ecu isn't using it as a speed signal on NA's...….but worth a look.
Maybe something to do with battery voltage? amperage? I don't know but hey worth mentioning to you.
Lastly does the rev counter work? could be bad connection on or in ECU? I had a damp ecu issue before, since they are prone to water damage from roof leaks when in the original car. Corrosion can start later on.
I would be seeing if I could borrow an ecu to test and changing the cam sensor as they do go weak with age.
Can you clip a tester onto the HT lead and see if its the spark cutting and not something silly like fuel pressure?
Good luck!
|
|
|
|
Post by doubletrouble on Nov 5, 2019 23:09:51 GMT
On the basis you have tried just about everything I had a strange issue with a 1.8 doing something similar, ran for seconds and died. I changed the alternator as that was the original fault and it ran perfectly afterwards. Now I know it shouldn't make a difference as the ecu isn't using it as a speed signal on NA's...….but worth a look. Maybe something to do with battery voltage? amperage? I don't know but hey worth mentioning to you. Lastly does the rev counter work? could be bad connection on or in ECU? I had a damp ecu issue before, since they are prone to water damage from roof leaks when in the original car. Corrosion can start later on. I would be seeing if I could borrow an ecu to test and changing the cam sensor as they do go weak with age. Can you clip a tester onto the HT lead and see if its the spark cutting and not something silly like fuel pressure? Good luck! Hey thanks for the advise. Id have never thought of the alternator. Got a new afm coming... and a spark tester..... fingers crossed |
|
|
|
Post by doubletrouble on Nov 8, 2019 12:49:49 GMT
On the basis you have tried just about everything I had a strange issue with a 1.8 doing something similar, ran for seconds and died. I changed the alternator as that was the original fault and it ran perfectly afterwards. Now I know it shouldn't make a difference as the ecu isn't using it as a speed signal on NA's...….but worth a look. Maybe something to do with battery voltage? amperage? I don't know but hey worth mentioning to you. Lastly does the rev counter work? could be bad connection on or in ECU? I had a damp ecu issue before, since they are prone to water damage from roof leaks when in the original car. Corrosion can start later on. I would be seeing if I could borrow an ecu to test and changing the cam sensor as they do go weak with age. Can you clip a tester onto the HT lead and see if its the spark cutting and not something silly like fuel pressure? Good luck! Hey thanks for the advise. Id have never thought of the alternator. Got a new afm coming... and a spark tester..... fingers crossed Bugger.... Changed airflow sensor to no avail. Got a spark checker. The spark continues after the engine dies. I checked all four cylinders and they all the same. So it has to be fuel? What would cut the fuel ignition off? Immobiliser? Another sensor? I have tried another fuel pump and changed the filter. Could be that both pumps are ify but doubt it. Have not measured fuel pressure yet but will try. Any thoughts people for a desperate man ! |
|
|
|
Post by Stiggy on Nov 8, 2019 14:01:02 GMT
if you are desperate you could unplug the fuel pump and stick pos from the bat via a fuse, if it runs OK then your getting closer to the cause of the issue
|
|
|
|
Post by camspeed on Nov 8, 2019 14:10:41 GMT
fuel pressure regulator failed?
|
|
|
|
Post by morrin88 on Nov 8, 2019 15:42:13 GMT
Hey thanks for the advise. Id have never thought of the alternator. Got a new afm coming... and a spark tester..... fingers crossed Bugger.... Changed airflow sensor to no avail. Got a spark checker. The spark continues after the engine dies. I checked all four cylinders and they all the same. So it has to be fuel? What would cut the fuel ignition off? Immobiliser? Another sensor? I have tried another fuel pump and changed the filter. Could be that both pumps are ify but doubt it. Have not measured fuel pressure yet but will try. Any thoughts people for a desperate man ! We must have different issues then as my fuel pump keeps running for 1-2 seconds after the engine cuts out. Looks like we’ll be on different paths from here unfortunately! |
|
|
|
Post by doubletrouble on Nov 8, 2019 15:48:08 GMT
Bugger.... Changed airflow sensor to no avail. Got a spark checker. The spark continues after the engine dies. I checked all four cylinders and they all the same. So it has to be fuel? What would cut the fuel ignition off? Immobiliser? Another sensor? I have tried another fuel pump and changed the filter. Could be that both pumps are ify but doubt it. Have not measured fuel pressure yet but will try. Any thoughts people for a desperate man ! We must have different issues then as my fuel pump keeps running for 1-2 seconds after the engine cuts out. Looks like we’ll be on different paths from here unfortunately! Same path matey. Fuel pump runs on after engine stops for a couple of seconds on mine as well. |
|
|
|
Post by morrin88 on Nov 8, 2019 15:49:07 GMT
We must have different issues then as my fuel pump keeps running for 1-2 seconds after the engine cuts out. Looks like we’ll be on different paths from here unfortunately! Same path matey. Fuel pump runs on after engine stops for a couple of seconds on mine as well. Well we’re in it together then as I’m exactly the same. I’m now thinking ecu, could be wrong but picked up one to try |
|
