AEM EMS no start, no prime (details inside)
Jan 3, 2014, 04:57 PM
#1
AEM EMS no start, no prime (details inside)
Running AEM EMS v1
Issue:No start, also noticed when key is first turned on, there is no fuel pump prime.
Tested fuel pump relays 1, 2 and 3. All fuses are good and not blown. Relay #2 was bridged from pin 1 and 4 and the fuel pump primes. This ensures that all relays are working correctly. Did the same when relay 1 is swapped with relay 2, pump still primes. It seems like EMS transistor ground for relay #2 does not switch??
Engine still doesn't start even while the relay 2 is bridged and fuel pump is priming. Fuel pressure is solid 40 psi.
MFI relay has been swapped in with a known good and still no start. Fuse 8 was also checked and confirmed good.
Can someone CONFIRM 100% if the fuel pump would still prime IF the Crank Angel Sensor is bad??? Please only respond to this if you're 100% positive because i don't want to be chasing something that isn't real.
As and added note, vehicle was also exhibiting random stumbles ("dieseling") on ignition off. Engine would stumble 2-9 times after ignition was switched off. I minimized this effect by changing out the spark plugs with a smaller gap, BUT it still happens on occasion. Not sure if it could have any relation.
The car started fine just last night, and 5 hours later the car wouldn't start. A new battery has been installed and has plenty of life, so the battery is 100% no issue.
Spark: Removed COP and placed a set of new plugs in the COP, placed against the valve cover and had a buddy crank the engine, found no spark present.
Tomorrow I will be checking the injectors with a noid light to confirm ecu signal to injectors. I really don't see a point as im positive there will be none. But I figure its better to check then not to. As well as I'll be checking aem ems ecu that it is receiving powerand ground. I'll check in aem tuner that the crank sensor is reading rpm. It definitely appears to be a crank sensor issue or an ems issue of some sort.
Issue:No start, also noticed when key is first turned on, there is no fuel pump prime.
Tested fuel pump relays 1, 2 and 3. All fuses are good and not blown. Relay #2 was bridged from pin 1 and 4 and the fuel pump primes. This ensures that all relays are working correctly. Did the same when relay 1 is swapped with relay 2, pump still primes. It seems like EMS transistor ground for relay #2 does not switch??
Engine still doesn't start even while the relay 2 is bridged and fuel pump is priming. Fuel pressure is solid 40 psi.
MFI relay has been swapped in with a known good and still no start. Fuse 8 was also checked and confirmed good.
Can someone CONFIRM 100% if the fuel pump would still prime IF the Crank Angel Sensor is bad??? Please only respond to this if you're 100% positive because i don't want to be chasing something that isn't real.
As and added note, vehicle was also exhibiting random stumbles ("dieseling") on ignition off. Engine would stumble 2-9 times after ignition was switched off. I minimized this effect by changing out the spark plugs with a smaller gap, BUT it still happens on occasion. Not sure if it could have any relation.
The car started fine just last night, and 5 hours later the car wouldn't start. A new battery has been installed and has plenty of life, so the battery is 100% no issue.
Spark: Removed COP and placed a set of new plugs in the COP, placed against the valve cover and had a buddy crank the engine, found no spark present.
Tomorrow I will be checking the injectors with a noid light to confirm ecu signal to injectors. I really don't see a point as im positive there will be none. But I figure its better to check then not to. As well as I'll be checking aem ems ecu that it is receiving powerand ground. I'll check in aem tuner that the crank sensor is reading rpm. It definitely appears to be a crank sensor issue or an ems issue of some sort.
Jan 3, 2014, 05:05 PM
#2
Go to ENGINE START > ADVANCED START > ADVANCED ENGINE START and make sure Crank All is selected (this turns the injectors on. Unchecked turns them off) also make sure Fuel Pump Prime has something in there for example 2.00 sec ( if you enter 2.00 make sure to press ENTER after entering 2.00)
Just wanted to start here with questions. Let me know what you have for settings.
-Jason
Just wanted to start here with questions. Let me know what you have for settings.
-Jason
Jan 3, 2014, 05:48 PM
#3
Go to ENGINE START > ADVANCED START > ADVANCED ENGINE START and make sure Crank All is selected (this turns the injectors on. Unchecked turns them off) also make sure Fuel Pump Prime has something in there for example 2.00 sec ( if you enter 2.00 make sure to press ENTER after entering 2.00)
Just wanted to start here with questions. Let me know what you have for settings.
-Jason
Just wanted to start here with questions. Let me know what you have for settings.
-Jason
I do greatly appreciate the help.
Jan 3, 2014, 07:06 PM
#4
Can you send me your calibration file to n2boost@yahoo.com? I will see if anything looks abnormal. I am new with troubleshooting evo's but I understand how everything works on them and will try to figure this out.
Jan 3, 2014, 07:19 PM
#6
Yeah you seem to be on the right track. Once you check for spark and if you find there is none then I'd tend to think it's the crank sensor. I'd go down and unplug mine now for you but our baby is sleeping. If you want me to test anything for you tomorrow let me know! I've been in your position before and would be glad to help!
Jan 3, 2014, 07:22 PM
#7
Yeah you seem to be on the right track. Once you check for spark and if you find there is none then I'd tend to think it's the crank sensor. I'd go down and unplug mine now for you but our baby is sleeping. If you want me to test anything for you tomorrow let me know! I've been in your position before and would be glad to help!
So gonna take a look at it tomorrow, and possibly run a switch.
I'll update tomorrow.
If you could disconnect the crank sensor and see if you get the prime "whenever is convenient" for you, i'd appreciate that.
Thanks again,
Dave
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Jan 3, 2014, 07:28 PM
#8
So the car ran for a little? Did you switch from a stock ecu. Also check the outputs to and look at the setting for the fuel pump. Older cals had the pump requiring 50 degrees air to work.
The crank/cam sensor don't impact the fuel pump prime.
The crank/cam sensor don't impact the fuel pump prime.
Last edited by TheBoz; Jan 3, 2014 at 07:32 PM.
Jan 3, 2014, 08:39 PM
#10
Vehicle has been running. Just this morning, no start. It has had the stumble for some time. But never seemed to cause much of an issue. More annoying than anything.
I cant see it being the output at this point but I will give it a check. When I jump fuel pump relay #2, fuel pump primes and still no start. We have determined that the EMS seems to be missing a ground or power supply. EMS is not communicating with AEM tuner. Also note that there is no spark as well, fuel prime and I can almost guarantee no injector pulse.
Thank you for the input on the crank/cam sensors with prime. We weren't sure about that.
Appreciate the help. Dave or I will certainly get back to the thread with results.
I cant thank you enough for checking that. It really helps out a lot. I have a bad feeling the EMS packed it in. Tomorrow we will be checking the power and grounds at the EMS and checking for possible shorts to b+, b- or opens at the 4 main EMS power/grounds. If they all show up clean as I fear they will... then the ecu id expect to be the cause. Reason for me thinking this is that all the fuses and relays are clean. Car sat overnight without moving the car and then BAM, this happens... Cant see a wire breaking/shorting overnight (although it was -24 deg C without the windshield last night). But with these cars... ANYTHING is possible..
Jan 3, 2014, 09:28 PM
#11
1 more thing to check, disconnect all 5v sensors. MAP, TPS, Oil Pressure, Ect. Try to connect with AEM Tuner.
If that does not let you connect, then disconnect all sensors, and try to connect.
If that works then cool, if it does not then you can check the eprom.
Another issue on the series 1's if it is an old one is the eprom will become loose. You might just need to reseat it.
If disconnecting all the sensors works then you need to recalibrate your TPS(Most Likley), you never want it to read 0% I should be about 1-3% when closed.
Other than that if you cannot connect with AEM Tuner/Pro then you could have something wrong with the ecu, or the usb/serial cable.
The USB uses the same 5v source as the 5v sensors, so if you have a sensor fail that is tied to 5v's it will cause all sorts of crazy to happen.
If that does not let you connect, then disconnect all sensors, and try to connect.
If that works then cool, if it does not then you can check the eprom.
Another issue on the series 1's if it is an old one is the eprom will become loose. You might just need to reseat it.
If disconnecting all the sensors works then you need to recalibrate your TPS(Most Likley), you never want it to read 0% I should be about 1-3% when closed.
Other than that if you cannot connect with AEM Tuner/Pro then you could have something wrong with the ecu, or the usb/serial cable.
The USB uses the same 5v source as the 5v sensors, so if you have a sensor fail that is tied to 5v's it will cause all sorts of crazy to happen.
Jan 3, 2014, 09:38 PM
#12
1 more thing to check, disconnect all 5v sensors. MAP, TPS, Oil Pressure, Ect. Try to connect with AEM Tuner.
If that does not let you connect, then disconnect all sensors, and try to connect.
If that works then cool, if it does not then you can check the eprom.
Another issue on the series 1's if it is an old one is the eprom will become loose. You might just need to reseat it.
If disconnecting all the sensors works then you need to recalibrate your TPS(Most Likley), you never want it to read 0% I should be about 1-3% when closed.
Other than that if you cannot connect with AEM Tuner/Pro then you could have something wrong with the ecu, or the usb/serial cable.
The USB uses the same 5v source as the 5v sensors, so if you have a sensor fail that is tied to 5v's it will cause all sorts of crazy to happen.
If that does not let you connect, then disconnect all sensors, and try to connect.
If that works then cool, if it does not then you can check the eprom.
Another issue on the series 1's if it is an old one is the eprom will become loose. You might just need to reseat it.
If disconnecting all the sensors works then you need to recalibrate your TPS(Most Likley), you never want it to read 0% I should be about 1-3% when closed.
Other than that if you cannot connect with AEM Tuner/Pro then you could have something wrong with the ecu, or the usb/serial cable.
The USB uses the same 5v source as the 5v sensors, so if you have a sensor fail that is tied to 5v's it will cause all sorts of crazy to happen.
If you think of anything else we should do/check please feel free to let us know. Thanks again guys!
Jan 6, 2014, 08:18 PM
#15
I hope you have a backup of your cal. Most of the times if it is a bad prom on the ecu then they might not be able to recover the cal that is on the ecu. So be ready for that.
Now don't take that as the word of god, just saying it is a 50/50 if you will get the cal from the ecu.
Now don't take that as the word of god, just saying it is a 50/50 if you will get the cal from the ecu.
