2000 Camaro. 6.0L, 4l80e, 60#, Slot style MAF, 102mm intake and throttle body.
I have been fighting this car for weeks. I have it great when warm but to get it to cold start has been a chore. I have the throttle blade open so when warm my IAC counts are very low, around 10 in park. This way I have more room for positive airflow when cold. AS you can see in the tune I have added a ton of friction and startup airflow when cold. The IAC counts go to 323 on a cold start but the car will not idle without keeping the throttle open a few %. I took off the throttle body and the channel looked pretty small so I put it on my mill and opened it up some. That helped but still will not start and run unassisted when dead cold.
Im assuming my BRAF is low because I have the throttle body open so far? From 175 on I can log and have STIT very close to 0. I have startup and friction airflow delayed so much to try and keep it running that I cannot get a good log on airflow at colder temps.
I have tuned three HCI auto camaros since this car showed up and have not had any issues with them. Im at wits end. I need advise. Please.
This data log I just did. It doesnt show the difficulties I have with a dead cold start but it still did the "pop off and die"
I have also been fighting cranking fuel. Ive had to take so much out. It could be a fuel issue when cold as well. Thoughts? The crank fuel for 176* and warmer is accurate. Not sure about colder temps.
What 60# injectors are they? When I graph it out the desired airflow is quite a bit higher than what your getting. And it didnt look like it fired and caught until it richened up in the start log.
You have alot of stuff changed that should have not been touched.
I can tell you most of the NW's I have tuned like more BRAF especially without drilling a hole(which I don't recomend). Don't worry about the counts. My DD starts well in the cold and hot with 100-120 IAC counts. You are probably gonna have to also recalibrate your idle screw on the TB. Try .59-.63v.
I would put it back to stock and start over. Its too much stuff to try to sit through and tell you to change. Example, you have 10g's for start up airflow initial. Thats alot.
The cranking VE is set rich from the factory to compensate for different variables. Your prime and sec VE tables look a little rich if this is a cammed car.
Basically sounds like you need more air with the current VE tables settings.
Last edited by POWERZONE; 07-25-2014 at 11:41 AM.
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I realized I was so engrossed about it not starting that I had not tuned VE. So I did that.
I lowered the throttle blade and have tps at .55 The log attached is a cold start. Warm start and drivabiltiy is great. Please advise. Thanks!
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