VAFC Stalling Issues?

randomman84 · 09-16-07, 05:34

Hey all,
Its time to give the camry a rest and I'm getting a new car. Maybe y'all can help me a bit?

I am looking at a sick 97 prelude here in atlanta and had a question.
The car has been under a car cover with the battery disconnected for about 3-4 months and when he brought it out today and hooked it up and started it, I revved the engine a couple time in the low 2000 range and the 4th time it stalled. I looked at him funny and he told me that it did it because the 1 it hadnt been run in a while and 2, because the VAFC lost all the settings due to the battery disconnect. Is this likely? We let it run for a while longer and I revved it again through the throttle body to about 5-6k rpm and it worked like a charm. Should I be concerned about it? I am taking it to the mech. on wednesday and if all checks out I'm gonna buy it. Ill take it to the dyno next week to get it tuned bc he hasn't had it tuned since he put in a couple of things. Thanks for your input and let me know if you need more info.
PS. the car has 110K and is an automatic. Thanks
Morgan

zoomzoom mazda5 · 09-16-07, 05:51

This is a good question for the Honda Forums, bet someone could give you a quick answer. And probably the right one, or a very good mechanic could find out the problem for you.

jshillin · 09-17-07, 12:20

What is done to it that it requires a vafc?? You can only add/remove so much fuel with an afc. They are usually just bandaids...

randomman84 · 09-17-07, 06:57

a bunch of things im not sure why he got one, i suppose to make sure he was getting the most out of the air flow and such.. I dont know a whole lot about the stuff just yet.

JDookie · 09-17-07, 07:52

I don't know a lot about Honda's in particular, but I do know a few things about cars in general, and whenever you reset a vehicles pcm, it has a learning period that it has to go through before it runs like normal.

After a hard reset like the one performed by disconnecting the battery, you are supposed to start the engine and let it idle with all of the accessories in the OFF position until it gets to running temperature. This sets the idle speed. After that, shut the engine down, let it cool off, and then restart it, except this time with all the normal accessories in the ON position. This will set the idle with a bit of an engine load. After this, you are good to go like normal.

I have gone through this procedure, and have also just started it up and immediately started driving. Both end up with the same results, but I noticed that when I just start driving immediately, the car will run rough for short period of time before clearing up.

I suggest driving the vehicle on and off the highway at varying speeds and loads, and see what happens. This is the only way to really know for sure.

Shane Camp · 09-20-07, 09:52

'

Quote:

Originally Posted by randomman84

Hey all,\r\nIts time to give the camry a rest and I\'m getting a new car. Maybe y\'all can help me a bit?\r\n\r\nI am looking at a sick 97 prelude here in atlanta and had a question.\r\nThe car has been under a car cover with the battery disconnected for about 3-4 months and when he brought it out today and hooked it up and started it, I revved the engine a couple time in the low 2000 range and the 4th time it stalled. I looked at him funny and he told me that it did it because the 1 it hadnt been run in a while and 2, because the VAFC lost all the settings due to the battery disconnect. Is this likely? We let it run for a while longer and I revved it again through the throttle body to about 5-6k rpm and it worked like a charm. Should I be concerned about it? I am taking it to the mech. on wednesday and if all checks out I\'m gonna buy it. Ill take it to the dyno next week to get it tuned bc he hasn\'t had it tuned since he put in a couple of things. Thanks for your input and let me know if you need more info.\r\nPS. the car has 110K and is an automatic. Thanks\r\nMorgan

\r\n\r\nI\'m not a pro but...\r\n\r\nSounds more like a timing issue and maybe IACV too... (no biggie)\r\n\r\nI don\'t think the VAFC uses volatile memory (looses settings when powered off), it uses non-volatile memory (keeps settings regardless of constant power). It sounds like the VAFC may not have the best settings for this engine setup or it\'s IACV or timing. If the motor has not had any significant upgrades then set all VAFC settings to null or zero so it is not doing any work, the engine should not stall then. However, if there are some modifications and the VAFC is not set correctly that could be the problem too. In addition, my VAFCII hatch has similar issues where some hestitation exists, but I believe it\'s due to the advanced timing setting on my hatch vs. the VAFC.\r\n\r\nHope it helps'

Shane Camp · 09-20-07, 10:34

not sure whats up with my reply above but heres the synopsis

sounds like a timing issue or IACV vs. VAFC.

My VAFCII hatch studders if it isn't warm, but I have aggressive settings and advanced timing

a PCM reset could help too

start troubleshooting with simple tactics first like the pcm reset, fuel settings, idle settings, etc..

randomman84 · 09-20-07, 09:39

thanks for the replies. I bought the car and have not had an issue since. it coulda been a million things. but it hasnt come back so i think im good. Thanks!