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AFK
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Discussion Starter #1 (Edited)
Hi,

I am helping a friend with his 2jz-gte engine, all stock internals with a single turbo and 700cc Fuel Injector Clinic High Impedance Injectors.

We can get the engine started up fine, reliably, with around 2ms of fuel on the "cranking pulsewidth". It just cranks ALOT before finally getting that initial fuel pulse.

I have tuned about 50 cars before so I've done all the routine checks, the pressure of fuel is great, it primes early/quickly, and I give it a second before turning the key etc...

I noticed the computer doesn't realize the engine is cranking for a while, it takes about 1.5 seconds before I see any action on the laptop so I was thinking maybe his sensor was old (I read somewhere the camshaft sensor can get old and cause this issue) however, the fact that it starts and runs fine once started seems to indicate the cam sensor is still working in some way.

will love to post up the initimate details, however, I was hoping someone had this issue (well known issue?) and has a simple fix.

thanks

(MORE DETAILS):
1. sync early is on, I've tried it off as well
2. I tried disabling all the injectors except cylinder #1 to count the revolutions necessary for fuel. The engine routinely turns over about 15-18 compression cycles (about 6 complete revolutions of the crankshaft, 3 solid seconds of cranking with a powerful battery) before fuel is injected.
3. Increasing the cranking pulsewidth was the first thing I tried, naturally. It simply floods the engine and takes even longer to start (when fuel finally does inject, you have to clear flood/floor the throttle to move some of it out of the cylinder to get it to fire)
4. I am willing to play with the injector timing, however, the issue here is that the fuel is waiting several revolutions, not just 2 or 3, so I do not feel this is applicable yet.
 

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What firmware is the ECU on? 01v24 had a bug where when "Crank Inject All" was set to ON, no fuel would be injected during the "Initial Crank Pulse" period, which is the first set of injection events (in this case the first 6 events). If it was set to OFF, the first injection for each injector would be a combination of the value in Crank Injector Time and Crank Inject All, but the first event would be injected sequentially instead of batched. Once the first event was completed, subsequent cranking injection events would come from the Crank Injector Time table. 02v02 firmware fixes this and allows a single simultaneous "batch" pulse of all injectors before switching to sequential during cranking when Crank Inject All is set to ON.

Also, regarding the delay in detecting Engine Speed, have a look at the Adv Pickups tab at the channels Cam Count and Crank Count. These should immediately start incrementing as soon as the starter is engaged. If there is a significant delay on either or both of these channels, then it does sound like it's a cam/crank sensor pickup issue. These cars use mag/VR sensors, so they do get stronger with RPM. Therefore, a weak sensor, or one with too large of a gap, will produce its weakest signal during cranking, meaning this is when it's most likely to give you trouble.

Beau
 

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AFK
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275 Posts
Discussion Starter #3 (Edited)
Thanks for the reply, I've seen those topics during my search. The firmware is V2.x . This is my first time on the version 2 AEM, first time using USB for a stand-alone too lol. what has this world come to? Actual USB? that was my response.

I am used to getting that batch fire at first light, that is what seems to be missing. I will let you know about the counts when I see the car next, thank you, great idea.

please help find our round 1 batch :D
 

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Sounds good. Make sure that the AEMTuner software version is at least v3.2, and the firmware is "02v02" (displayed at the bottom of the screen when connected, next to "ECU Connected").
 

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AFK
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Discussion Starter #5 (Edited)
thanks my friend, I got it all sorted out a while ago. 99% operator error :D

a few observations,
-I miss the resolution setting for the fuel map
-I don't like how the default is to pull global fueling % based on pressure when in vacuum, it doesn't make any sense since engines are not linear with respect to map pressure vs RPM in those situations. Boost is a different story, once you have a VE curve for the engine you can add global gas to a target a/f ratio. But that same concept does NOT apply during medium/strong vacuum situations like cruise and light part throttle, and so a VE curve is useless. I just do not feel this is an acceptable default setting, if the user wishes to add it later then great.
-still can't believe I am using USB successfully

Just waiting for a while for the car itself to be ready, once my friend gets the exhaust fabbed up, we will be having some fun
 
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