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Discussion Starter · #1 ·
So picked up the car yesterday from Dallas and drove it back to AZ. After about 50 miles it started stalling when I push in the clutch to coast. It does this about 75% of the time. The RPM just dips all the way to 0 and stalls out. I have the aem and got a crash coarse on it yesterday and that is my only experience with it, so anything dealing with changing setting, please be detailed.

2nd problem: Made 650whp on 91 octane. Changed to race fuel and the car won't boost over 28 psi. After 22 psi the car only gains 10-20hp over the next 6 psi. Found a blown im gasket and fixed it. Still same problem. The pressure before and after intercooler is the same, pressurized the intercooler and no leaks, pulled the intake side of turbo apart to check fins and appears to be no damage. Anyone got any ideas on what I can try?
 

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Your stalling is most likely due to your idle settings. I don't have my laptop in front of me or I would post up the procedure (I am at work). If someone doesnt response before I get home I will try and post it up.

You should also be able to search on here, and on the aem forums for the idle setup information.

Concerning your boost issue. Is the car not boosting past 22psi, or is it not gaining power past 22psi?
 
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Do you still have IAC valve? If this valve stick or is slow to respond, it will not "pick up" your RPMs when you press the clutch in

Or artificially bump the idle up via AEM to 1200rpm+ and that will prevent stalling for now
 

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'95 TT
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I bet it's the difference in atmospheric conditions (altitude). AZ is alot different than Texas and you'll likely have to adjust your idle settings.

When I sold my northeast car to a guy in AZ, it wouldn't idle there, yet it would idle fine in the northeast. It was due to the difference in altitude.
 

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Discussion Starter · #5 ·
I will try raising the idle to see if that helps.

It will boost to 28 psi but not go over it. It doesn't make power per psi like it should after about 22psi. We disconnected the wastegate, and had our hand over the dump tube (to make sure it wasn't releasing to atmosphere) to try and get it to boost higher, still won't go over 28. With the t88h that I have, should have gone to 50 psi
 

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Discussion Starter · #6 ·
Ok, ran into another problem. Went to connect to the aem and its says it can't connect because it is unable to fine aemusb.dll The shop had a serial port on their computer, and I'm having to use a usb to serial adapter. Anyone know how to fix this problem?
 

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HighCompression+Boost=Win
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You need to make sure you have the right driver on your serial port. Then in AEM options tab ECU-->CONNECTION PORT----->Select USB Connection make sure usb is selected then you should be fine, if you are using the crappy radio shack usb to serial adapter its a PITA to find the xp drivers if you lost them.
 

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Alpine Hardtopper
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Yes...it seems like lots of people have trouble connecting to the AEM with a USB-->Serial adapter. If you go on the AEM forum it seems like people recommend some brands over others. Some of the cheap ones just don't work. Sorry to hear about the problem with the car. It takes a little while to get up to speed on the EMS, but they're very powerful once you know how to use them.
 

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Discussion Starter · #9 ·
I open up the device manager on my computer, and there is no tab for ports. I looked in all the different files listed but didn't see anything listing ports. Is there another way to change and check the ports?
 

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HighCompression+Boost=Win
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If the devise if working properly it would be listed in the usb section of the device manager, it should show that it is a usb to serial adapter. If it does not show up, you probably don't have the right driver for it. What brand adapter is it?
 

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T88 YOU
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iac is bolted to the underside of the intake manifold if you have a virtual works which is what it looks like in your avatar. how do you have the vacuum hoses ran on the wastegate, if you put the pressure source on the wrong nipple it can cause this.
 

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Discussion Starter · #14 ·
No I have a greddy im. I believe it is on the rear and top of the im but am not 100% positive. Is there anything I can do to check and see if the IAC is the actual problem and fix it? All vacuum hoses are ran correctly.
 

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Discussion Starter · #15 ·
Ok. Can now connect to AEM. Cruised around tonight and without the A/C on, the car didn't stall once. So what setting is it on the AEM that I actually need to change to prevent it from happening when the AC is on?
 

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HighCompression+Boost=Win
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You may need to change your fuel when the ac is on, try to get the car to idle at 14.5-15:1 then see how it does. I had to raise my idle from 750 to 950 for mine to run right. I am sure there are others on there that would know some good info. Also if you post this in the Dyno Tuning section a lot of people might be able to take your settings and adjust them for you. Good luck man.
 

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T88 YOU
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if your a/c is the problem then you need to adjust your "idle a/c load comp" value, increase it until your rpm is the same with the a/c on and off. you can also mess with the "a/c on delay" to minimize the idle change, adjust it until you can barely tell a change in rpm for a split second.
 

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Discussion Starter · #18 ·
At idle it is normal with the a/c on. That is when it idles! The problem is it just goes down to 0 rpms and dies; however, if I am going from say 4th to 3rd and it goes to zero and all the interior lights come on like it died, I can hit the gas in 3rd and the car will work. It will do that in all gears except 1st and 2nd.
 

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Alpine Hardtopper
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In regards to your boost problem...what turbo is on the car? Have you looked at a compressor map for that turbo? In many cases (like with the stock twins) as you push their limits, they get so ineffecient that even though the boost is higher, the temp is so much hotter that there's not significantly more air going in to the engine. But w/o knowing what turbo you're running I can't say much more.

Also, on the AEM there is a parameter that is supposed to help the idle pick up sooner when the engine isn decelerating. But off hand I don't remember what it's called and I don't have mine nearby. I'm sure SupraDupa will remember this though.

Just to recap - Your car idles fine once it's idling. But when you push in the clutch and the engine RPM's drop down to start idling the engine usually dies?
 

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T88 YOU
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what are your idle feedback settings at? they should be in the 400-1700 range... also the "idle on if TP over/less" settings, should be about 5% or so...
 
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