another update: i disonnected the safc from the afm wire (reconnected the stock afm wire). now the car will start without engine code. but it will not idle and seems to struggle and backfire when i rev it. i think its the pressure sensor. i teed off the vacuum nipple on the firewall side of the intake (now there r 2 tees- 1st is goin to vpc pressure sensor, 2nd is factory- stock pressure sensor, heater valve, and cruise). i mounted sensor on firewall behind the throttle body, a little higher just as hks instructions said. where did u guys mount the pressure sensor and run the line to??
Help! Oil pressure and VPC issues
- Thread starter supra_ed
- Start date
I mounted mine right behind the Intake Manifold and Used a T-Fitting right off the back side of the intake where the small Fitting is coming out of it. As long as you have the line coming off the Pressure sensor Pointing straight down then I dont think its your Pressure sensor. I put up a Diagram earlier so take a good look at it and retrace your wiring.
What Injectors are you running and what chip do you have?
Robert
What Injectors are you running and what chip do you have?
Robert
So Im assuming that you Hardwired your SAFC wiring into the HKS VPC main Harness then? Im asking because you would not believe what people have done with these setups. Im pretty sure you know what you are doing, Just making sure that all. Pulling fuel shouldnt be an Issue even though that is alot of fuel to pull but Ive seen it done before and work Flawlessly.
Robert
Robert
yes sirrrr!! ive seen people making over 700whp on this exact setup!! i cant even get the mother to idle, lol!!
i instaled the safc before i got the vpc (old setup) so the safc is wired into the car harness still. to get it to start i disconnected the afm wires and stuck them back together, like stock. still dont get why its running so rich and not wanting to idle. i tried to adjust the idle nob, pulled fuel, and it seemed to want to idle a little higher (a/f did not change) but still died. it also seems to be surging, bouncing between 500-1000rpm before dying.......
i instaled the safc before i got the vpc (old setup) so the safc is wired into the car harness still. to get it to start i disconnected the afm wires and stuck them back together, like stock. still dont get why its running so rich and not wanting to idle. i tried to adjust the idle nob, pulled fuel, and it seemed to want to idle a little higher (a/f did not change) but still died. it also seems to be surging, bouncing between 500-1000rpm before dying.......
What is the a/f ratio? Sounds like it's just too rich, which is pretty much what you'll get with 720's at anything resembling a decent fuel pressure and no other device but the VPC to trim the afm signal.
Add in the s-afc in the wiring AFTER the VPC, ie the grey wire coming out of the VPC going to the ECU side of the subharness. The AFM wire in the engine harness does not connect to anything in the VPC subharness since the VPC creates the afm signal on it's own. Cut the grey, VPC head unit side to AFC orange, ECU side to AFC pink.
BTW, I know Will Neely has a dyno chart somewhere claiming 700+ rwhp, and while I'm sure I could have done it on a perfect day with a VPC in my car, day to day driving SUCKED. Ignition timing was retarded significantly to combat detonation due to the ultra low afm signal input to the ECU, even with base timing set to 10. That combined with a significantly different response out of the 720's resulted in frequent bogging, very late spoolup, and overall just poor drivability. I wouldn't waste your time with the VPC...MAFT-Pro with ign timing control or a standalone.
Anyways, if you must, crank the response knob all the way up. Turn idle until it...idles, then guess depending on the day and the direction of the wind for where to set the gain.
Add in the s-afc in the wiring AFTER the VPC, ie the grey wire coming out of the VPC going to the ECU side of the subharness. The AFM wire in the engine harness does not connect to anything in the VPC subharness since the VPC creates the afm signal on it's own. Cut the grey, VPC head unit side to AFC orange, ECU side to AFC pink.
BTW, I know Will Neely has a dyno chart somewhere claiming 700+ rwhp, and while I'm sure I could have done it on a perfect day with a VPC in my car, day to day driving SUCKED. Ignition timing was retarded significantly to combat detonation due to the ultra low afm signal input to the ECU, even with base timing set to 10. That combined with a significantly different response out of the 720's resulted in frequent bogging, very late spoolup, and overall just poor drivability. I wouldn't waste your time with the VPC...MAFT-Pro with ign timing control or a standalone.
Anyways, if you must, crank the response knob all the way up. Turn idle until it...idles, then guess depending on the day and the direction of the wind for where to set the gain.
Let me make sure Im reading you correctly.
You have the SAFC wired into your Engine harness and then you have the VPC connected. If this is the way you have it then that is incorrect. You should have the VPC connected the the engine harness and the SAFC wired directly into your VPC Main harness, not the engine harness itself. Dont cut any of the 4 wires going from the VPC to the HKS Harness, If you look really close at the HKS Harness, you will see where the Grey wire goes into the harness there will be another wire coming out of the same port, that is the wire that you want to cut and install your SAFC Pink and orange wire into.... Let me get a Pic of mine tomorrow and I will shoot it over to you. The Diagram I put here a few Post ago is the way your SAFC should be wired into your HKS main harness, not the engine harness.
You have the SAFC wired into your Engine harness and then you have the VPC connected. If this is the way you have it then that is incorrect. You should have the VPC connected the the engine harness and the SAFC wired directly into your VPC Main harness, not the engine harness itself. Dont cut any of the 4 wires going from the VPC to the HKS Harness, If you look really close at the HKS Harness, you will see where the Grey wire goes into the harness there will be another wire coming out of the same port, that is the wire that you want to cut and install your SAFC Pink and orange wire into.... Let me get a Pic of mine tomorrow and I will shoot it over to you. The Diagram I put here a few Post ago is the way your SAFC should be wired into your HKS main harness, not the engine harness.
It actually won't matter, grey wire between VPC and subharness or grey wire in the subharness between the connectors. This is because the grey wire from the VPC is connected to the engine wiring side of the subharness. See this pic of HKS subharness TV-02.
http://oldschool.supracentral.com/gizmo/vpc_h2.jpg (thanks to ol' Larry A)
I recall splicing mine between the two connectors of the subharness now, but again, it should not matter.
http://oldschool.supracentral.com/gizmo/vpc_h2.jpg (thanks to ol' Larry A)
I recall splicing mine between the two connectors of the subharness now, but again, it should not matter.
You are correct, It wont matter but as long as that is the only wire that he cuts then he should be good. Just thinking that i would be easier to cut the wire on the TV-02 harness which is the way I have mine. Im hoping that he doesnt have SAFC/VPC and not VPC then SAFC
alrighty. i think the safc is wired in correctly- i tapped the grey wire in the vpc harness. the car will start and idle now (the safc and the vpc both "seem" to be working). but when i try to rev it a/f shoots completely lean and it backfires a lot. if i hold it at around 2-2500rpm it will go back rich again, just the initial hesitation and lean/backfire is pissin me off now lol. i know one of u said to crank the response up (which i tried) but not working. about where did u guys have urs set?? is the hesitation always gonna be that bad? .....cant wait till i get the aem....
i just took it for a quick test drive. ran like an unbelievably massive piece of shit. sputtering, backfiring, struggling to get to speed. a/f was a little lean but not bad?????
im about ready to scrap this thing and keep the car in the garage for a month or so until i can get the aem.........this sucks
im about ready to scrap this thing and keep the car in the garage for a month or so until i can get the aem.........this sucks