2zz engine not warming up with AEM EMS-4 | AEM
9 posts / 0 new
Last post
omarjmedina
Offline
Last seen: 2 years 11 months ago
Joined: 09/22/2014 - 17:08
2zz engine not warming up with AEM EMS-4

Hi Guys,

I'm facing a strange issue. I have a Toyota Corolla XRS 05-06 with 2zz-ge engine. With factory ECU the engine reaches it normal operating temperature (90-95 C), but when using the AEM EMS-4 the engine keeps cold around (40-60 C), it momentaneously reaches (70-80 C). With engine running after a long ride, when I touch the engine valve cover I don't feel it as hot as when riding it with the factory ECU.

Termostat is recently changed, I think it is not the issue. If I change to factory ECU the engine warms up to normal operating temperature.

I'm using a boomslag harness where the Factory ECU controls the A/C and Dash gauge and the AEM EMS-4 has full control of ignition timing, fuel, VVT and VVL.

Any of you guys have faced any similar issues?

BR,

Omar Medina

AEM_NS
Offline
Last seen: 1 hour 5 min ago
Joined: 06/06/2014 - 09:31
What is it that you think the

What is it that you think the EMS could be doing to keep the engine from warming fully?

omarjmedina
Offline
Last seen: 2 years 11 months ago
Joined: 09/22/2014 - 17:08
Hi AEM_NS,

Hi AEM_NS,

That's what I want to understand. The engine should be warming up to operating temperature with the EMS, when I put the factory ECU the engine warms up to operating temperature.

This is a rare behavior that I would like to understand,

Br,

Omar Medina.-

AEM_NS
Offline
Last seen: 1 hour 5 min ago
Joined: 06/06/2014 - 09:31
My question was to get you to

My question was to get you to ask yourself what is it that the EMS could do (or not do) that would make the car not warm up.  To the best of my knowledge, thermostats are still entirely mechanical and there is generally no means for an EMS/ECU to control coolant temp directly.  The biggest question in my mind is how are you quantifying that the engine isn't fully warming up?  If relying on the stock temp gauge, are you sure it's still functioning correctly now that you've put a stand alone EMS on the car?  If relying on the coolant temp channel in the software, are you sure that your temp sensor is calibrated correctly?  Saying you can put your hand on the engine after driving isn't very quantitative.  Something more empirical like a mechanical temp gauge or a thermal temp gun would be more readily acceptable than just how it feels on your hand.

Does the 2ZZ in a Corolla have some kind of electronically controlled coolant flow valve that's not being controlled by the EMS?  Are your radiator fans on all the time?  Even if you were running so rich that the engine ran slightly cooler, it should still reach operating temp.  The short answer is that there's really no way that the EMS could some how change the mechanical cooling system unless it has something to do with what I mentioned above.  

Smaay
Offline
Last seen: 5 years 6 months ago
Joined: 10/16/2014 - 05:52
you might have to run the

you might have to run the EMS4 in parallel with the stock ECU, In the celica world, the stock ECU runs the gauges too.

 

omarjmedina
Offline
Last seen: 2 years 11 months ago
Joined: 09/22/2014 - 17:08
Hi smay,

Hi smay,

I have months with aem in parallel with stock ecu controlling gauges. Car run perfectly with no issues so far, but I dont still find out the issue with the temperature.

Br,

Omar

evil93evo
Offline
Last seen: 5 years 6 months ago
Joined: 02/10/2015 - 21:15
Check the cooling fan on and

Check the cooling fan on and off temperatures in the EMS-4, more than likely they are set to come on lower than the factory ECM. The engine will have trouble making it up to temp in a timely manner if its fighting the fans. The factory probably turns the fan on at around 200-205 deg F and back off around 190F ish. Otherwise check all of the grounds.....For everything! So many electrical problems end up being because of poor grounds.

ma70tt
Offline
Last seen: 5 years 4 months ago
Joined: 11/13/2014 - 07:32
We found that the boomslang

We found that the boomslang harness was defective. The wires they use for the USB connector are too small for the aem pin. Our solution was to double the stripped wire back over the I Sula ti on and re crimp. No problems since. Of course boomslang was completely useless in diagnosis and solution.

www.capitalcityperformance.com
ma70 5.3 tt 4l80e 9" 4 link, c10 5.3 tt 4l80e 8.8 coming soon...

omarjmedina
Offline
Last seen: 2 years 11 months ago
Joined: 09/22/2014 - 17:08
there is an issue with

there is an issue with boomslang harness. I recommend to use an aem water temp sensor to aem ems-4 and use factory water temp sensor with factory ecu. You may also re-route fan relay connections from aem ems4 to factory ecu in order to free gpios.