Thread: EMS Question

How reliable is an EMS running car for a DD? I am looking into getting a new ride and it has a EMS running everything.

What should i do or look for ?

That depends on the aftermarket EMS, the quality of installation, and the quality of the tune. Many cars with aftermarket EMS can be DD reliable sometimes even more so than factory. Other times the EMS is inadequate, the installation is poor, or the tune is not great and you can have problems.

I've experienced both situations. I had an EMS that was installed poorly (I never installed the idle valve wiring correctly) and had relatively primitive and confusing start-up configurations causing cold start issues on an SR20.

My current EMS is completely reliable and indistinguishable from an OEM ECU in that respect, possibly more reliable.

What type of EMS does the car have and who installed it?

Ive been running an AEM EMS for the past 3 months put over 1500 miles on it so far.

only bug i have is when i cold start it.(takes 3 cranks before it will idle) Thats getting fixed next week, for free

Thanks for the info and help Ben. It is an AEM EMS and the guy DD the car now with no problems. I just do not want to run into problems and not know what to do with the EMS. Would i need to dyno and tune the car everytime or if there this a problem




Does a tuner have to fix that or is it someone you can do?

If the car runs great now, it will be just as reliable with the AEM EMS as it would be with an OEM ECU. If you do run into problems, frankly having an AEM EMS is even better for diagnosing and fixing problems than a stock ECU. You won't need to dyno tune or re-tune the car unless you make a change that would warrant that (change of injectors, running more boost, new cams, etc.). If there is a mechanical problem like your plug wires go bad or something, and you replace the plug wires, you'll be all fixed. No need to re-tune.

unijabnx2000 could decide to fix his cold start problems himself if he wanted to, or he can take it to a tuner. Anyone with a laptop with serial port and serial cable can work on an AEM EMS (or use a serial-to-USB adapter for newer laptops). Base-line calibrations for our engines are very good and problems like that are easily fixed with a little know-how on all kinds of common engine configurations.

^ what he said

Im letting him fix it:
1 it will be fixed faster if i let them
2 I like their shop
3 They are fixing it for free

Thanks Ben for the help. I vote you for president

The AEM is perfectly capable of powering a daily driven car.

I have had them in various cars from EVOs, S2000s, 240s, etc and all of them are driven on a regular basis.

The determining factor for most engine management systems is the quality of the tune. If he has been driving on it with no problem, than more than likely you are good to go.