Just some questions if he is being truthful... Ok the first one is not really a biggie but, he had to send in my old unit to get the upgrades from AEM. The problem is when the car is warmed up it doesn't want to start and the battery dies. Ok the real question I have is he also told me I have to keep my FMU in due to the size of my injectors (440's) He said the unit needs to stay in due to how small they are, if I had bigger injectors I could take the FMU out. Is he BS'ng me to save work or has anyone heard of this before? Thanks -Rob

 

I have the same problem with the AEM EMS ... sometimes the car will not start up when warm. What did they say is the cause? Is the only way for me to get it resolved to send it back to AEM for an upgrade?

 

I have some hot start problems but have been assured it's a very simple setting adjustment. Haven't got around to looking into it yet.

As for the 440s I would have assumed they were big enough. I wonder what the duty cycle is at full boost? Sometimes if it's too high (above 90%) it is wise to up the fuel pressure instead but not at the same ratio as a stock Vortech.

 

LikeAus said, You would have to see the Duty cycle to know if the injectors are big enough. Myself and several others have run 440cc injectors on Stock boost Vortech SC's with no FMU, and a e-manage. Most everyone that upgrades injectors and EMS or Emanage on a SC'd car removes the FMU.

 

As for the upgraded version, I apologize. I was told it had the latest version uploaded to it.

 

With regards to upgrades, I was under the impression that they were all user upgradable. Are some of the upgrade steps 'Return to base' procedures or is your tuner just a luddite?

 

Thanks for everyone's help so far. No problem Skip I was told that I wasn't going to get charged for the upgrades AEM is doing right now. I also thought that it could be changed by the user as i mentioned to him at the shop, bt he assured me that a certain upgraded piece was missing?

 

What upgrade are you guys talking about? One point it seems like a software upgrade. I thought he was just talking about the simple resistor change for the cam angle sensors to help sync faster by making the voltage easier to read by the AEM EMS.

 

yes that is what it is the resistor change, thank you. I'm still wondering about the FMU though.

 

Just to chime in, with little to no knowledge of AEM details. Hot starts are often related to vapor lock. Often a solenoid will change the vacuum seen by the stock regulator to solve this issue by changing the fuel pressure. The computer should have parameters for compensation based on water temp.

I am not sure if this is the problem you have, but if the AEM is similar to the Power-FC/Datalog-it I used to run on the rx-7, then it should allow for this correction during hot starts.

As far as the FMU...I have a theory about that...if you remove your FMU you are left with a few fuel components from your supercharger kit. The primary culprit is the high pressure/high flow fuel pump. When you had the FMU installed in the return line, it needed the additional pressure from the pump. Once removed, the high pressure pump now overpowers the stock regulator's diaphram.

The solution is to toss the pump and if you will run 1:1 fuel pressure then the stock pump is good...I know because I tested it. Alternatively you could just replace it with a high flow only pump (not high flow/high pressure).

cheers

W