AEM Possible Limp Mode - Please Help!

[kcd]

Ok guys, I really need some help here...

I'm running an AEM EMS Series 1 in my '97 Eclipse. It takes a few cranks (which I hear is normal) to start up, and then it runs fine. While it's warming up, my battery light (battery is healthy and is fully charged), A/T temp light (this car is a manual), and brake light stay on on the dash. Everything else appears to be normal. But after awhile, all three lights will shut off and the car will immediately start bogging and then die shortly after. It dies too fast for me to even catch any readings. The only thing I did notice was that ignition timing started climbing to 30deg and then it dies.

After it dies, I can start it back up again like normal. All three lights come back on, and it idles fine. After waiting for awhile, nothing had changed. The lights continued to stay on and it was idling fine. I can't seem to figure out what causes this issue and I'm having a hard time replicating it (other than from a cold start).

I just recently installed this ems, so I haven't done anything more than idle for right now.

AEM no longer offers support for the Series 1 so they wouldn't help me. I also tried contacting the list of qualified technicians on their website but came up empty-handed there as well.

Any help would be greatly appreciated. Thank you!

 

[Mello]

This doesn't sound like an EMS issue, more likely electrical on the car. Have you hookup your laptop & monitored all your basics like battery, AIT, CLT, etc. to see if all your input sensors are functioning? Before you can do any tuning you first need to make sure your car is 100% good mechanically & nothing malfunctioning. There's a pre-made "setup" template in AEMPro software that is for monitoring/setting up all the basic EFI input signals. The AEM really can't cause electrical issues like your dash lights problem and what not.

 

[kcd]

Before the ems install, everything was peachy. Everything was operating normally. I just find it odd that my car will enter this "limp mode" after just idling and nothing else. If it were a separate electrical issue, I feel like it would happen at random times, not while idling after it warms up.

The only way I can replicate it is from a cold start. After about 10 minutes of idling, this issue kicks in and it dies. I haven't been able to make it happen any other way.

At first, it almost seemed like it was temperature-related. While warming up, it runs fine. But then it's like it goes into closed-loop mode and that's where the problem lies. I'm not sure if closed-loop and open-loop modes even exist with an ems, but that's the only thing I could come up with.

It's obvious that I'm new to this and I should probably take it to a shop to get professionally done, but I really enjoy learning about all the aspects of tuning and I just want to do this myself. Hopefully with all the help from you guys, of course.

 

[Mello]

Compare your calibration loaded into your EMS with the "start up" cals AEM provides in the software install. Look for the any differences on all the parameters that would not be specific to each vehicle. These non vehicle specific parameter would be all thing you don't deal with when tuning. AEM is fully programmable. If you program it for open & closed loop then it will do it. Start by turning off "O2 Feedback" so it stays in open loop & then start adjusting fuel so you can get stable enough to idle & work up from there. Use the timing map from the "start up" cal while you sort out being able to hold an idle. Also, begin with it at normal operating temp. Cold start is pretty much one of the last things you'll address. Also which EMS do you have? Is it the EMS for the DSM 2G platform? The 1G & Evo boxes have different interface boards so you can do the plug 'n tune without having to switch pins in the connectors to the EMS from the stock wiring harness.

Also, the AEm does not have a limp mode but it does have "fail safe" sensor limits which you can set in case one goes bad & out of range.

 

[kcd]

I'm using the ems specifically for the 2g dsm. I also do have the start up cal loaded. But when the lights turn off, everything just goes down the toilet.

I'll try logging it and maybe you'll be able to spot something that I'm missing.

 

[Mello]

don't think I need a log. Start by posting up your cal your running. I checked your profile & it doesn't say much for example; "you drop in an engine & tranny and here we are". What does this mean? Are you still using the MAF? What AEM WBO2, gauge type? I have a 97 GSX manual & did know there was an A/T temp? Like I said earlier, I don't think your problems is with the EMS. Is your alternator good? How do you know?

 

[kcd]

I work at an Advance and had my alternator tested a couple months back. It tested good then, but maybe things changed and it's starting to go out. I'll pull the alternator and test it tomorrow at work.

When I installed the ems, I also went ahead and set up speed density. Installed a GM iat sensor and a mist-style 3bar map sensor. So no more MAF.

The wideband is an AEM UEGO.

As for the A/T temp light, I'm just as lost as you are. I've never seen it until now. Perhaps the previous owner had to swap out the cluster for some reason? I'm really not sure.

 

[Mello]

Just curios but what who makes, brand is your alternator?

 

[kcd]

To be honest, it's been on the car for a couple years now. The previous owner changed it before I bought it. It's just odd because it's never given me problems before. But I'm sure there's a chance that it's the culprit.

 

[boostdawd]

Check the voltage with the car running. Those lights come up when there's an issue with your alternator.

 

[o0GuitarKid0o]

I hve to agree with boostdawd I bet your voltage regulator is shot In your alternator
Although I would double check your battery connections if your useing the stock clamps I would replace them

What does your alternator charge at?
Old battery?
Any recent issues or strange occurrences
Almost sounds like the 3 lights of death

 

[boostdawd]

If it does turn out to be the alternator, replace it with a Saturn one from a 95-99 Saturn. I'm using one from a 99 with internal fan blades as opposed to the external ones from a 96. Charges great! Seeing low to mid 14s at idle and cruise. High 13s on wot.

 

[kcd]

Alternator tested bad... I'll replace it tomorrow and see if that solves my issues. Maybe I'll give that Saturn alternator a try. Thanks guys!

 

[boostdawd]

I would. Like others said, it's one of the best mods for your car. Make sure to pay close attention to the wiring. There is quite a bit of grinding involved so set aside time to get everything right. Don't want to be pulling your hairs out like me and have to redo it over and over. Before u install and tighten down the alternator if u do decide to go the Saturn route, connect the pigtail and battery+ to the alternator. Switch the key and make sure the same lights come up. That will ensure the alternator is connected properly.