AEM Starting

Talk EMS and Computer related performance

AEM Starting

Postby cmonteiro1 » Wed Sep 22, 2010 6:56 pm

Anyone else have issues starting with an AEM ecu. Car runs great, but for some reason, it takes forever to start. It turns over and turns over and turns over... and then just starts like nothing. Any help is greatly appreciated.
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1991 ST185
Mods:
Aussie DP, 3in Exhaust, Wideband A/F, BayArea FMIC, HKS SSQ Blow Off Valve, Forge Waste Gate Actuator, AEM ECU, SARD 800 , Walbro Pump, ATS Fuel Rail Mod, ATS Fuel Pres. Reg. Mod., 60 trim upgraded ct26.
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Re: AEM Starting

Postby Celi-GT4 » Fri Sep 24, 2010 12:20 am

yes never could figure it out. It helps if you turn to on position and wait for fuel pump to build pressure (listen for it)
12.4 @ 115mph Topeka Kansas NA2005
12.2 @ 109mph blew HG Moroso 1/08
Sold out, now on stock 3rd gen
Blitz ecu, dp,exhaust, tien ss, carbon driveshaft,light wheels/brakes,os giken twin plate
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Re: AEM Starting

Postby cmonteiro1 » Fri Sep 24, 2010 10:29 pm

Ive tried that.. It seems like sometimes it works, sometimes it doesnt. I wonder if its just a quirk that has to do with aem. It would be nice to be able to fix it. Do you have issues with your battery running down if you don't run the car in a while? I know two cars with aem that have that problem, and Im wondering if that's the cause.
1991 ST185
Mods:
Aussie DP, 3in Exhaust, Wideband A/F, BayArea FMIC, HKS SSQ Blow Off Valve, Forge Waste Gate Actuator, AEM ECU, SARD 800 , Walbro Pump, ATS Fuel Rail Mod, ATS Fuel Pres. Reg. Mod., 60 trim upgraded ct26.
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Re: AEM Starting

Postby Celi-GT4 » Sat Sep 25, 2010 12:13 am

I ran a small battery and yes had that problem although I have a 3rd gen with blitz ecu now and have the same problem but it takes twice as long to run down 10days instead of 4. I installed a terminal kill switch from moroso for that purpose and also backup theft prevention.
12.4 @ 115mph Topeka Kansas NA2005
12.2 @ 109mph blew HG Moroso 1/08
Sold out, now on stock 3rd gen
Blitz ecu, dp,exhaust, tien ss, carbon driveshaft,light wheels/brakes,os giken twin plate
Celi-GT4
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Location: Park City, Utah

Re: AEM Starting

Postby banshee 101 » Sat Sep 25, 2010 6:40 pm

im running the aem and have the same issue with the start, in winter its even worst.
i've looked into it and i dont think their is much we can do, i still love the ecu
91 ST185 JDM
w/ Mods
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Re: AEM Starting

Postby cmonteiro1 » Mon Sep 27, 2010 10:13 pm

Def. Love the ecu. Small price to pay I suppose... freaks me out everytime though.
1991 ST185
Mods:
Aussie DP, 3in Exhaust, Wideband A/F, BayArea FMIC, HKS SSQ Blow Off Valve, Forge Waste Gate Actuator, AEM ECU, SARD 800 , Walbro Pump, ATS Fuel Rail Mod, ATS Fuel Pres. Reg. Mod., 60 trim upgraded ct26.
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Re: AEM Starting

Postby AvivB » Mon Sep 27, 2010 10:33 pm

Just a guess: maybe the AEM ECU doesn't ignore the AFM while cranking to enrich the mixture like the OEM ECU does.
It can be tested easily, specially if one of you have open filter instead of the air-box.
Just remove the filter, put your finger to hold the AFM open a bit more that it should open on idle and ask a friend/brother/sister/mom/dad/dog to try and start the engine.
(as soon as it start running, remove your finger.)
If it start quicker than before, I'm right...
If I'm right, I might be able to build a small circuit that will replace your finger (for this use) and fake AFM reading while engine is cranking...

Disclaimer: I don't have and didn't had an AEM ECU, all the above is based on my knowledge on this engine, ECUs in general, knowledge in electronics and the data from this thread.
/Aviv

('92 ST182RC 1/1 :-) )
"Life is not the fact that your heart is beating but the number of times you miss a heartbeat..." (www)
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Re: AEM Starting

Postby cmonteiro1 » Tue Sep 28, 2010 4:50 pm

One of the primary benefits of installing AEM is that you can get rid of the AFM.
1991 ST185
Mods:
Aussie DP, 3in Exhaust, Wideband A/F, BayArea FMIC, HKS SSQ Blow Off Valve, Forge Waste Gate Actuator, AEM ECU, SARD 800 , Walbro Pump, ATS Fuel Rail Mod, ATS Fuel Pres. Reg. Mod., 60 trim upgraded ct26.
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Re: AEM Starting

Postby AvivB » Tue Sep 28, 2010 8:18 pm

Ok, so the AEM ECU use air pressure and temperature to calculate the required fuel...
This will be more tricky to "fake"...
Basically what I suggested in the test is to give the engine rich mixture for starting...
I'll think about that...
/Aviv

('92 ST182RC 1/1 :-) )
"Life is not the fact that your heart is beating but the number of times you miss a heartbeat..." (www)
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Re: AEM Starting

Postby MWP » Wed Sep 29, 2010 12:53 pm

Im not familiar with the AEM, but there is only one way i cant think of to trick it into giving you more fuel... by changing the value of the coolant temp sensor while cranking.
So that would mean using a relay to switch over to a set resistor value imitating low coolant temp when the starter is engaged.
Not such a hard thing to do.

Unless its cranking too rich, in which case you should chuck the cold start injector or do the opposite to the above.
My collection of GT4 documentation: http://gt4.mwp.id.au
Daily: Celica GT4 ST185 (~170kw/atw)
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Re: AEM Starting

Postby AvivB » Wed Sep 29, 2010 4:25 pm

I though about cooling the sensor more... but the difference between 20-30 Celsius to even -10 Celsius will not enrich the mixture enough...
The sensor readings are around 25K ohm at 20 Celsius and 250K ohm at 100 Celsius so cooling/faking it to even 0 ohm will not help...

Sorry for the stupid question, but did anyone of you try calling AEM about that?
I know that when I needed them for the gauges issue they where very responsive...
/Aviv

('92 ST182RC 1/1 :-) )
"Life is not the fact that your heart is beating but the number of times you miss a heartbeat..." (www)
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Re: AEM Starting

Postby MWP » Wed Sep 29, 2010 10:52 pm

AvivB wrote:I though about cooling the sensor more... but the difference between 20-30 Celsius to even -10 Celsius will not enrich the mixture enough...
The sensor readings are around 25K ohm at 20 Celsius and 250K ohm at 100 Celsius so cooling/faking it to even 0 ohm will not help...


First... temp sensors are not linear, making it read -10degC can be done.
Second... faking -10degC will make a huge difference, youll get something like 20-40% more fuel.
My collection of GT4 documentation: http://gt4.mwp.id.au
Daily: Celica GT4 ST185 (~170kw/atw)
Project: Toyota RA28 '77 Celica (1UZ-FE powered)
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Re: AEM Starting

Postby banshee 101 » Thu Sep 30, 2010 3:31 pm

we should post the issue on the aempower forum
91 ST185 JDM
w/ Mods
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Re: AEM Starting

Postby cmonteiro1 » Thu Sep 30, 2010 4:21 pm

Just did a google search and came up with this link which provides a few possible options.

http://forum.aempower.com/forum/index.p ... v.html#new
1991 ST185
Mods:
Aussie DP, 3in Exhaust, Wideband A/F, BayArea FMIC, HKS SSQ Blow Off Valve, Forge Waste Gate Actuator, AEM ECU, SARD 800 , Walbro Pump, ATS Fuel Rail Mod, ATS Fuel Pres. Reg. Mod., 60 trim upgraded ct26.
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Location: Phoenix, AZ

Re: AEM Starting

Postby vip09 » Sun Oct 17, 2010 5:29 am

I had an AEM EMS on my Alltrac, and never had starting issues like that. It always cranked right up like a stock car. If you want to look at my map I can email it to you for comparison.
Best GT-S STOCK times: 1/4: 14.788 @ 94.98mph 1/8: 9.640 @ 75.87mph
Best Alltrac times: 1/4: 12.2 @ 115mph 1/8th: 7.9 @ 91mph
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