mase1

put back the stock themostat.

its not completely uncommon for the vehicle to have voltage drop on higher rpms. You are saying the voltage goes from 14.0 v to 12.0?

stena

hey mase hit me on stefce@hotmail.com,maybe we can tune my car,i am free now and the weather is great...
I have been trying you on msn but no luck

Stefce

yiannakos

it drops approximately 12,4v to 12,8v

the Fan Switch is very easy to change but the thermostat needs a bit of work if i remember well


i will put back the stock thermostat and i will keep you informed
i hope that this will solve the issue

thanks a lot for the input

wildcardtrd

I'm sorry, maybe I'm just not reading this correctly, but you're thinking that the thermostat and fan switch are causing a voltage drop around 6000 rpm as sensed by the AEM EMS??

...ummm....for one, the thermostat has nothing at all to do with the electrical system...I'm running a spoon thermostat that keeps my coolant temps at 155 when moving. The fan switch is going to cause a voltage drop whenever it calls the fans to run, plain and simple. Increase the amp load on a circuit, all other factors remaining the same, and the voltage will drop. Last time I checked, there was absolutely nothing wrong with 12.8 volts...hell, my voltage fluctuates over 1 full volt when the engine is running. If you want your voltage to stay at 14.4, you'll need a voltage stabilizer...it's that simple. I don't see how 12.8 volts is anything to be concerned about, and it certainly shouldn't affect your AEM EMS tune in anyway shape or form.

Again, unless I missed your point, I don't think there's anything wrong with your system at all...I think you guys are nitpicking at something that's an unavoidable and frankly unimportant issue.

FYI, my battery voltage floats constantly between 12.5v and 13.8v, and it has absolutely ZERO negative effects on my car. I've been running my EMS for about 18 months now.

mase1

switching the thermostat is certainly not going to affect the voltage drop.

That will fix your issue of your wondering coolant temps. Operating temperatures should be above 170 degrees. I never recommend any cooler thermostat unless you have no other choice.

As I stated before, the voltage drop is normal. ive seen them go as low as 12.1V at redline. As long as your battery offsets for the injectors you are running are setup correctly, then you really shouldnt see a problem.

yiannakos

[QUOTE=wildcardtrd,Jan 18 2008, 02:52 PM] I'm sorry, maybe I'm just not reading this correctly, but you're thinking that the thermostat and fan switch are causing a voltage drop around 6000 rpm as sensed by the AEM EMS??

the problem that affects tuning is the coolant temp that drops alot and so the ems adjusts wrongly the air, fuel and i dont know what else.

but its anyway nice for me to know that there is nothing wrong with the volt drop

wildcardtrd

re-reading your initial post, the temperature swing detected by your coolant temp sensor is normal...the EMS only adds fuel if the coolant temp is below 125 F.. you can check this in your cold start enrichment tables. Any coolant temp above 125, and the computer stops adding additional fuel to the pills. Everything in your setup is running perfectly fine.

FYI, when sitting at idle on a dyno on a hot day, my coolant temps will steadily climb to 200, then the fan kicks on, and brings it back down to 170, where it shuts off....but I have a 155 degree t-stat, so before each pull, I let it sit with the A/C on (forces both cooling fans on) until the coolant temps get down to 155 (where the tstat closes back off), turn off the air, let the compressor cycle off, then hit another run. Consistent 155 coolant temps make for good dyno runs and consistent autocross laps

I wouldn't worry at all about your temperature swing...its perfectly normal and well within the operating range of your coolant system.

yiannakos

The problem is that the temp if falling instantly and stays there as long as you keep the revs at that point .
when you step off the throttle then the temp raises again instantly to 194f.
the temp change is taking place with an abnormal fast way

yiannakos

today i had the stock fan switch and stock thermostat back on but nothing changed again

next week we are going to try and tune it with e manage ultimate just to see if the same thing will happen

yiannakos

i have some videos of what is happening and the way that it happens.
please take a look at the coolant temp when the engine revs close to 6000rpm


video 1

video 2

video 3