Rep Power: 0

I just got my car back from the head swap being done, timing belt changed, and aem pulleys installed, they ran into a problem with the key for the new ecu not turning the car on at all, so they stuck with the old ecu and used the new harness, and i'll just have to get a key flashed before i use the new ecu. On strange thing was the check engine light stayed on and they said there was only one o2 sensor connector on the harness... but said it ran fine.

Well anywayz... the car drove home fine and i didn't really notice anything different. But i have to drive home now, from Georgia to Pennsylvania. And i just went for a quick ride to get some stuff and as i turned into the parking lot the car stahled! Turned it back on and drove to a parking spot and it stahled again!!!

I decided not to worry about it and went into the store. Came back and set the monitor on the vafcII to check some things out. Cause the Vto light had been coming on so i figured everything was cool. Well the monitor showed me the Vti wasn't working or not showing up on the vafcII.

The car idles alittle strange now and everytime i go to stop it freaking stahls on me. I have to make a very long trip home tomorrow and i'm alittle afraid.

Hope someone can help me as to what the problem is. Thanks

 
Rep Power: 336

you need the ECU from an ex. or the vafc2 is enough if you don't have a ex ecu. that is where your problem is. did you connect the blue wire?(vtec selenoid) so it could be controlled by the VAFC2?

 
Rep Power: 0

yes it seems wired right... from what xproductions had in his DIY... i don't get it at all. I have the vacfII set to what gearbox had in another thead... it's pretty much set to stock.

You don't need the ex ecu... xproductions used the dx one too.

 
Rep Power: 336

right, if you have the VAFC2 then you don't need a ex ecu. just wanted to say, you need one or the other.

 
Rep Power: 0

yep or both... but right now i have the dx ecu and vafcII cause the key that came with the ex ecu doesn't work with the ecu for some reason.

I searched a whole bunch of threads for this problem but didn't come up with a answer. This causes me major problems cause i signed outta Ft. Gordon today and after tomorrow i will homeless here unless i get back to Pennsylvania with the car running like this.

 
Rep Power: 336

r ya sure its the right ecu? for example, if you drive stick and get an auto Ecu it will not be the same...

 
Rep Power: 811

um your vafcII MUST be tuned on the dyno if you have a dx ecu!!!! You cant just have vtec and no extra fuel being sent. I wouldn't drive like that, your engine is gonna blow real soon. I sure hope you didn't go past 3k rpms alot.

Try and find someone who's done the head swap and at least use their tune settings until you can sort this out. Its not ideal, but better than driving the car lean. And you're sure they hooked all these wires right? and connected the vtec solenoid?


sorry to hear about the problems but this is a big deal.

okay, but the vafc needs to be tuned for vtec. alot of extra fuel is needed or you're gonna run lean and blow the motor.

 
Rep Power: 0

i'm not totally sure they connected the wires right... but i did give them every piece of info that is on this site about it. I checked the wiring... but not indepth... the vtec solenoid is connected though. Gonna take a gander at it in a min. I'm taking it back to the shop tomorrow... but i don't see what they can do that they haven't charged me for already.

MajinB... i'm still running with the original ecu right now.

I just found these... it's the most complete setup i could find on here... gonna reset the ecu and clear the vafcII and try it out.

Vtec Cont L-H 4500 > H-L 4000
Vtec Unmat 0%
Throttle point 15% narrow 40% wide


Narr. thr (Low Vtec)
1800(rpm) -4
2200 -4
2600 -4
3200 -4
3600 -4
4000 -4
4200 -4

Wide. thr. (High Vtec)
4600 + 5
5000 +5
5400 +6
5800 +7
6200+ +8

Is there a way i can tell if the vtec is kicking in without it sending a signal back to the vafcII? Is there a sudden change in anything like rpms, speed, etc. I really gotta get this figured out by 11am.

 
Rep Power: 336

you could do a DIY for a vtec light. that way you could know.

 
Rep Power: 0

I don't know how this guy had these settings cause the high & low vtec in wide & narrow don't go to some of these settings? I just tried it now and i couldn't set it up this way. Just gonna have to take it back to the shop and see what happens. I'm not sure if he wired it right.... since they used the new harness with the old ecu.... i told them to call me if they had problems... i so hate car shops right now.

 
Rep Power: 811

you can only tune the wide (full) throttle successfully. The narrow throttle settings will just be adjusted by the ecu anyway and are of no concern.

you need to tune wide hi and wide lo vtec. and the engagement point seems very high. usually its set to 2800rpms. but this is another problem...vtec is only supposed to engage when a rather large set of conditions are met, such as coolant temp, oil pressure, full throttle, and above 4500rpms on a normal ecu. forcing vtec with a controler will hurt the engine by engaging before these conditions are met. this is why its better to just use the ex ecu.

 
Rep Power: 0

i understand.... problem is i paid most of my $ for the pulleys and install done. The only way i can get the ex ecu to work is to pay for a flash and then i probably won't have the cash to drive home.

I'm half tempted to take out the ex harness and put the dx one in and re-wire it myself. The head install work is done and that's what i couldn't do myself.

 
Rep Power: 336

i thought they were unflashable...

 
Rep Power: 0

For those that don't wanna read the whole thing: I drove the half working car 700+ miles home and about to fix the issues i still have, tested it and the code came back for the o2 and cat... which is cause the primary ain't hooked up. Putting old wiring harness in... and following xproduction's directions... like the told the shop to do the first time!


Ok... well after i put my computer in my car and went back to the useless custom shop i had my work done at, note: they again told me everything was ok but i needed to get the EX ecu put in and a key cut... cause that's the only way to fix the issue, but the car would run fine until i got it done. After i left there i went to Honda cause it was my only option really....

well Honda had my car three hours trying cut a key! They installed the ecu but said it wouldn't let them access anything at all from it.... they said it's possibly a bad ecu, well they called it ecm... whatever. So they couldn't cut the key and cause the vafcII was connected they refused to touch anything at all.... figured as much.

So i took it upon myself and used Gearbox's advice and set the vafcII to a generic setup.... actually i used the last one he post. I took it for a test drive and seemed alright. I never went over 3k rpms and didn't push it really at all.

Well i had to be signed off of Ft. Gordon or i'd have to pay $30 a day just to stay there, my car was half working correctly, so i decided to risk it and drive home. Cause either way if the car broke down on the road or i was stuck in Georgia.... i was gonna be screwed.

Since being home i found out i'm throwing codes for the o2 senor and cat... understandable since for some reason the one for EX ecu doesn't have the o2 connector on it??? Plain and simple i'm putting the old wiring harness in and wiring the vafcII up and seeing what happens. Probably gonna hook up a kick light for the vtec too.... so i know it's working. Wish me luck

 
Rep Power: 811

must've gone to the wrong dealer. it does take a while to make the key, but if they cant read the ecu something is wrong with them. if they cant make a key tho, you're stuck with the dx ecu and vafcII, in which case you must get the a/f tuned on a dyno. but before that you need a woreking o2 sensor.

 
Rep Power: 0

was pm'ing you when you posted. Wouldn't it be better to just use the old harness rather than add a o2 sensor? Isn't that a pain.... i don't know how i would hook that up with the EX harness... but the DX one has the two that were there before. I'm thinking this is my best bet.... taking out the harness shouldn't be tough... wiring the vafcII might.

 
Rep Power: 811

ya take out the harness and use the dx one. vafcii is cake to wire. use the diagram i posted above. and the one in the manual that tells you what the colors mean. the diagram above is which wires in the ecu are tapped or cut.