Jinks engine build thread

I'm not familiar enough with the AEM EMS 2 but most decent ECUs have some kind of compensation that should make the difference between CA and Florida manageable. Most ECUs should have some kind of Long/Short fuel trim and timing trim tables. Again, i'm not an AEM expert by any means but i'd be surprised if it needs a retune just for altitude.

How do you know it's running rich? Is it the smell or do you notice it from your AFR gauge? Also, most tunes will run a bit rich while the engine is warming up.

I'd probably try to drive it around for a few hundred miles. A retune is never a bad idea as long as the new tuner is as good or better than the old tuner. He might screw up any good work already done :)

Post vids!!!
 
The AEM (like just about every EFI system ever) should prime the fuel pump to establish the fuel rail pressure prior to attempting to start the engine. If your fuel system is in good shape (the fuel pump discharge check valve seals instantly on shut down and the FPR does not drool out the by-pass line and none of your injectors drool) you may not need the prime pulse or just a very short prime pulse. If your fuel system is not in great shape it means that you may not be achieving the required operating fuel pressure prior to the start of cranking which delays start-up. A simple test of fuel rail pressure at rest and after priming will tell you whether you have a problem. If you are not achieving the service manual pressure with the prime pulse the length of the prime pulse is usually a set-up configurable variable or you can check out the operation of the check valve on the pump (a major hassle) or determine whether you have a leaky FPR or confirm that the injectors don't drool. Note that if you are using an aftermarket fuel pressure regulator, Aeromotive states somewhere in their application guides that their FPRs will not hold static fuel pressure in which case 'suck it up buttercup!'. Something to check out.

During cranking the engine speed will be way below the fuel map so the ECU typically does not use engine speed and MAP to calculate the fuel pulse width (also, the MAP value fluctuates like crazy during the initial couple of cranks). The fuel pulse width during cranking is typically established from a look-up table of pulse width versus engine coolant temperature. This table will be user configurable. Fuel PW values that are too short will make the engine hard / slow to start and PWs that are too long can flood the engine - making it hard to start. Take note of the engine coolant temperature when you are having the long cranking problem. If it only occurs at a specific engine temperature then it may be related to an incorrect value of fuel PW at that temperature. If the slow starting occurs at all engine temperatures then it may not be related to the cranking PW values and may be caused by something else. If you think that the fuel cranking PW may be the problem, have a discussion with your tuner about how they set those values.

I don't know how the AEM manages the C30 idle/auxiliary air valve. I have a C32 so I don't even know whether the C30 idle/auxiliary air valve is a PWM controlled valve or a stepper motor of some kind. Insufficient idle air can make the car slow to start. As a test, try pressing the throttle pedal down just a little to provide a little more air during cranking. If that improves things then it may be an indication of insufficient air during start up - again time for a call to your tuner to determine how they set the valve up.

The NSX has sequential / timed fuel injection and ignition. After you start cranking the engine the ECU starts getting timing signals from the crank and cam position devices. Once the ECU gets synced to these signals then it starts calculating ignition and fuel injection timing, so there will always be a slight delay. Good systems can establish sync in one crankshaft rotation or less. Depending on how your ECU was configured it may be slow to sync up. Do a data log on start up and record the voltage and the calculated RPM, fuel PW and ignition timing. The drop in logged voltage will tell you when the starter engages. If it takes several engine rotations before the ECU starts calculating the RPM, fuel PW and ignition advance, then the ECU is slow to sync up. If that is the case you need to go back to your tuner and find out whether there is a configuration problem or that is just the way the AEM system is when its connected up with an C series engine.

Tuning an engine for peak power is rather trivial (although errors are much more spectacular) compared to tuning to get fast reliable start up, particularly cold starts. Unless you have an environmental chamber to cool the engine, you really only get one try about once every 12 hours to test a cold start. If you get a partial start that results in the engine stalling you have blown the opportunity since the intake valves will have warmed up on that failed start which alters the starting conditions - wait 12 hours to re test! If the engine was slow to start; but, did catch, same thing. Wait 12 hours to retest with different settings. I have one engine that has taken more than 60 days of cold start tests to get the cold start configuration zeroed in, a lot of that was because there were some days where it just wasn't cold enough to do a test. Most people will probably be happy to get a configuration that allows them to get a start just because they don't have the patience or the money to give a tuner the time to zero in on a perfect start.

You might just end up having to live with the slow start-up.
 
I’m still trying to figure out what channels this gauge art runs it’s telemetry on. It’s frustrating and the website doesn’t tell you much of anything. It’s all hooked up somewhat but the channels are messed up. As for the car running with my laptop plugged in, the car as seen on aemtuner idles right at target of 14.4 afr. Rev the car and that value goes way down to 10 then back up to 16! At that time, the check engine light throws the car almost stalls, and then goes away. :mad:I’m almost too afraid to drive it!
 
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Mac Attack said:
I know AEM Series 2 and older standalones need to read the crank position twice before it will fire the coils. It's just a bit weird becaue it feels like it takes forever compared to OEM. Of course, the tune could still be off, or the cranking parameters could be modified.

Surprised to hear about the clutch... Of all four aftermarket clutches I've driven, this was easiest to drive. Maybe because its been 10 months since you've driven it too....
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I haven’t had any real seat time yet. Plus it was weird driving the car after 1 year of not driving it. Only went around the block. I’ll get used to it.
 
The car won’t even drive right. I just took it out a few hundred feet and the car stalled and shut down. WTF! This is not what I was hoping for.
 
Jinks said:
I’m still trying to figure out what channels this gauge art runs it’s telemetry on. It’s frustrating and the website doesn’t tell you much of anything. It’s all hooked up somewhat but the channels are messed up. As for the car running with my laptop plugged in, the car as seen on aemtuner idles right at target of 14.4 afr. Rev the car and that value goes way down to 10 then back up to 16! At that time, the check engine light throws the car almost stalls, and then goes away. :mad:I’m almost too afraid to drive it!
Click to expand...

That business with the AFR doing the dipsy doodle might be explainable. The AEM may be set up to look at the rate of throttle opening and lengthen the fuel pulse width to provide the equivalent of an accelerator pump enrichment shot. If the car needs acceleration enrichment you would typically tune the enrichment to maintain the target AFR while the throttle is transitioning open. If the tuner has applied too much delta throttle enrichment then that will result in the AFR going rich. If you lift the throttle completely so that the throttle plate goes completely closed the tune may cause a complete or partial fuel cut which causes the AFR to go briefly high until you get close to idle speed or you put your foot down on the throttle again. I have another car with aftermarket EFI and I have the throttle cut set so that if you lift the throttle completely in second gear the AFR will briefly swing to 19 or so. Causes some people to freak out; but, its not really an issue.

The MIL light (the AEM supports error codes?) and almost stalling is a more serious issue. The best case may be that the EFI is having a hard time transitioning back to idle which may be a matter of tuning the idle air control.

I would be inclined to go back to your tuner with a list of the specific issues and ask them to address them. They should be able to respond with some suggested tweaks.
 
As was told to me (I too have AEM Series 2) this ECU does not have a programmable idle circuit. That was added to the Infinity ECU which came out next. If your tune is not locked, you may have a good tuner look at it remotely by logging into your computer while synched to the AEM unit and look at the maps and tune the idle side. Just a thought.
 
Valhalla said:
As was told to me (I too have AEM Series 2) this ECU does not have a programmable idle circuit.
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Not sure about your reference to 'programmable idle circuit'. Both the AEM literature for the series 2 and the SOS literature for the 91-94 NSX application state full support of the factory idle valve on pre DBW cars. If you have a DBW car the AEM series 2 does not do throttle control (need to keep the OEM ECU to do that). Perhaps someone meant that since the AEM seems to be oriented to plug and play that the idle control circuit parameters are not configurable. That would indeed be unfortunate.
 
I spoke to Shad today. He thinks there is a loose ground somewhere hence the engine and oil light illuminating. I’m gonna fill it with 93 as it was tuned on that and see where we are at. There is barely any gas in it now and the Aem fuel pump sits less shallow than the oem. That could be my issue with stalling under load. I just haven’t had time for the checks so I am taking a break from it today. Will start fresh next week. I’ll fill it with gas, check my grounds, and take it for some drives. The fuel smell could also be the cats which were high pressure washed with oil, coolant, and gas when the motor exploded. They were washed thoroughly but Shad told me they still stink. Probably just need more miles. But boy, is the gauge art a pain in the ass to set up!
 
Here is a video of what the car is doing. I got the gauge art figured out thanks to Chris there. This is a tuning issue in my mind. When slowly raising rpms then lifting throttle, it stalls out. During faster revs, it is just fine. This is why I stall out when driving around my block to slow down for speed bumps. Thankfully, I have some contacts for an awesome tuner down here.
https://youtu.be/TjNFUVKemFU
 
Damn. I hope you figure it out soon, man. So you can finally get to enjoy the thing!

That's life, I guess. Just when you think you're in the clear, something always happens, lol.
 
comptonassdaniel said:
Damn. I hope you figure it out soon, man. So you can finally get to enjoy the thing!

That's life, I guess. Just when you think you're in the clear, something always happens, lol.
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Yeah it kinda stinks. Chris at gauge art has been very helpful and I got that under wraps. Ems 2 and gauge art is a mathematical mess.... Shad wants me to drive the car some. Just haven’t had time. Will report back.
 
I know Shad enough over the years that he would not give you a car that was crap to run...so even though you seem to be much better than average at all this aftermarket ecu stuff time for a good local tuner...
 
docjohn said:
I know Shad enough over the years that he would not give you a car that was crap to run...so even though you seem to be much better than average at all this aftermarket ecu stuff time for a good local tuner...
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I agree. Shad tried steering me away from this shit. I do not care what people read here... Aftermarket is pure garbage in forms of ecu. He steered me away from infinity as well. We will get it under wraps. It is just a bit of a learning curve for me. Not giving up yet. Just preoccupied with new house, new job, new atmosphere, etc.
 
well you are breathing the same atmosphere as DocL .....which includes copious amounts of nitrous....:tongue:
 
docjohn said:
well you are breathing the same atmosphere as DocL .....which includes copious amounts of nitrous....:tongue:
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It gives me the whaw whaws..... Kinda fond of it.
 
And by whaw whaws, I am referring to the feeling you get when taking a big ol’ hit of medical grade nitrous oxide....
 
It also seems like a tuning issue to me, but have you tried cleaning the idle air valve and throttle body? I had stalling issues while coming to an idle at red lights etc and that fixed it.

Yeah, I heard sketchy things about AEM infinity... and gauge art looks great but forum threads read all complaints on the pains of setting it up. I'm glad the customer support was there to the rescue. Post a vid of the gauge art!!!
 
Sorry you're going thru this. It's the worse thing to experience after throwing all that money at the car and a year's worth of time. It may not be of any consolation, but it took me at least 3 tuning sessions to get my car dialed in. As I've always said, WOT throttle is such a small part of the tune in the whole scheme of things. [MENTION=26435]Old Guy[/MENTION] has some great suggestions to help you troubleshoot.

Some folks ask why I still have my OEM ECU in the car while my HKS EMS is installed. [MENTION=26435]Old Guy[/MENTION] nailed it... The main reason it's there is because it's there to manage the idle characteristics. I believe it's also there to manage startup but i'm 50/50 on that. I think my HKS manages startup or at least alters it. The OEM ECU does some other minor stuff like monitor when to turn on the radiator fans but for the most part it's the idle control. It wasn't worth our time to have the HKS tuned to handle that. Perhaps that's your solution on the AEM EMS2. I know very little about that EMS.
 
I just drove the car today after gassing it up. No more stalling. The car is a complete MONSTER!!!!OMFG...
It is just brutally quick. Michelin PSS having a hard time holding grip while in second gear. Clutch is still pretty jerky and I need to adjust to driving it. Also, the car is still burning off coolant from the mufflers. Here’s a quick video of the gauge art. The best part about the gauge art is that it is 100% visible in the sun. I’m just waiting on Chris to send me the modified map sensor program so that the boost gauge reads correctly. Should have that today.
god I hate the sound of these uni filters though. Probably gonna put an oem back in there. Shad always installs them for more power but I hate the idle sound.
https://youtu.be/mQsw_59MSxg
 
So glad to hear. You probably did not have enough fuel in there for the fuel pump pickup to get suction. Sounds great. Enjoy.
 
One thing I really dislike about the ems 2 other than taking forever to start, is that when you power it up, it sounds like starting up a Tandy 2000 computer....
 
sounds like you might have some stale fuel from sitting at the shop for a year
 

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