VPC Hardwire help..(long)

1361 Views 15 Replies 3 Participants Last post by anthraciteboy, Nov 5, 2001

SyCK

Discussion Starter · Oct 31, 2001

Ok, I hope someone has an idea or thought on this, I think I'm just dumb and do not know what I am doing. Now, I wired it all up and put the resistor in the MAF plug in the engine bay and started the car..this was a week or so ago. I went out to the garage today to hook up my Apexi Rev/Speed meter (which doesn't splice into anything I had hooked up with the VPC) After getting it hooked all up I started the car and it idled like total ass, smelt of raw gas and didn't seem like it was pulling any vacuum. Now what I can't remember is when I cut the MAF line from the ecu to the MAF itself. I think I cut it before I tried to start the car last time but I may have cut it after. Could the resistor being in the wrong pins in the harness not looping the MAF right cause it to run like this. It feels like it is in a limp mode of sorts, I can't rev to high without it sputtering and trying to cut out... Now when I try to start it, it gives a lope or 2 of idle then dies. Please, does anyone have any idea what may be wrong?

Thanks.

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G

· #2 · Nov 1, 2001 (Edited)

If you're talking about the resistor that plugs into the harness where the MAF sensor did, then that would'nt be why the car is not running right. All that resistor does is fake out the ECU into thinking the MAF sensor is connected so you don't get the "!" and check engine light. BUT, make sure the resistor is connected right. Looking at the pins of the MAF connector with the rectangle notch facing up, the resistor goes across the second and third pin from the right.

If you're saying it was fine last week, then you installed something that didn't interface to the VPC and something is now wrong? Anyway, remove the Rev meter (if you don't see anything else obviously wrong) and put it back the way it was.

VPCRed --Supra ECU A-31
VPCBlack --Supra ECU B-69
VPCYellow-- Supra ECU Fuel comp back to B-66
VPCWhite --Supra ECU B-58

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SyCK

Discussion Starter · #3 · Nov 1, 2001

stoker6 said:
If you're talking about the resistor that plugs into the harness where the MAF sensor did, then that would'nt be why the car is not running right. All that resistor does is fake out the ECU into thinking the MAF sensor is connected so you don't get the "!" and check engine light. BUT, make sure the resistor is connected right. Looking at the pins of the MAF connector with the rectangle notch facing up, the resistor goes across the second and third pin from the right.

If you're saying it was fine last week, then you installed something that didn't interface to the VPC and something is now wrong? Anyway, remove the Rev meter (if you don't see anything else obviously wrong) and put it back the way it was.

VPCRed --Supra ECU A-31
VPCBlack --Supra ECU B-69
VPCYellow-- Supra ECU Fuel comp back to B-66
VPCWhite --Supra ECU B-58

Ok, I think I jumped pins on the resistor with one pin open between the two I bridged, I'll fix that tonight. I'm 99% positive I have the wires tapped into the right ones at the ECU unless the hardwire instructions off of the MKIV tech articles are wrong. The one thing I cannot remember, like I said earlier, is when I cut the wire for the MAF single..B-66. I went with the yellow wire from the VPC to the SFC then the SFC into B-66. I *think* then I started the car and it ran fine then the next day I cut the B-66 wire (behind the SFC tap) going into the engine bay. I didn't try to start the car again until yesterday after I hooked the REV/SPEED Meter up. I then noticed all the trouble. But, I can't be fore sure if that was when I actually did cut that wire. This is frustrating at the least.... Man, you're in Houston.. wanna come over and look at it with me

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G

· #4 · Nov 1, 2001

Sure, I'll help ya out. You have the fields SFC?? I have mine hooked up and it works flawlessly. I still have the wiring diagram for the ECU, SFC and VPC connections.

Anyway, I work in Clear Lake and live in Seabrook. Where ya at?

Greg

SyCK

Discussion Starter · #5 · Nov 1, 2001

stoker6 said:
Sure, I'll help ya out. You have the fields SFC?? I have mine hooked up and it works flawlessly. I still have the wiring diagram for the ECU, SFC and VPC connections.

Anyway, I work in Clear Lake and live in Seabrook. Where ya at?

Greg

Very Cool, I Live in Clear Lake off of Hwy3 and El Dorado. I tried to mail you at the NASA addy but it bounced back to me.. So shoot me a mail that I can reach you at or a number and I'll call. I usually get home around 5 during the week and I'm pretty much around most weekends so anytime you are available and can spare the time, it's cool with me. Thanks for the help

G

· #6 · Nov 1, 2001

lol, I'm about 2 miles down the road from you.

Yeah, My email was just changed because we moved from the nasa building to the boeing building.

[email protected]

How about tomorrow after work? Around 5:30 -6:00. That way I can drive my car to work and bring the wiring diagram also.

anthraciteboy

· #7 · Nov 1, 2001

Hey I live in Houston also. My problem is that i cannot control the fuel curve no matter what i set the VPC or AFC at. I think i have a wiring problem. If i could meet up with you guys to check out the wiring that would be great. My email is [email protected]
Thanks for your help

Henry

SyCK

Discussion Starter · #8 · Nov 1, 2001

anthraciteboy said:
Hey I live in Houston also. My problem is that i cannot control the fuel curve no matter what i set the VPC or AFC at. I think i have a wiring problem. If i could meet up with you guys to check out the wiring that would be great. My email is [email protected]
Thanks for your help

Henry

I was talking to Tommy one day about wireing these 2 up a couple weeks ago and we got on the subject of your car..what he told me is he thought you had the input and output wires on the AFC tapped backwards at the VPC <--> ECU.Have you reversed these yet and tried that?

G

· #9 · Nov 2, 2001

Euphoric said:
Ok, I hope someone has an idea or thought on this, I think I'm just dumb and do not know what I am doing. Now, I wired it all up and put the resistor in the MAF plug in the engine bay and started the car..this was a week or so ago. I went out to the garage today to hook up my Apexi Rev/Speed meter (which doesn't splice into anything I had hooked up with the VPC) After getting it hooked all up I started the car and it idled like total ass, smelt of raw gas and didn't seem like it was pulling any vacuum. Now what I can't remember is when I cut the MAF line from the ecu to the MAF itself. I think I cut it before I tried to start the car last time but I may have cut it after. Could the resistor being in the wrong pins in the harness not looping the MAF right cause it to run like this. It feels like it is in a limp mode of sorts, I can't rev to high without it sputtering and trying to cut out... Now when I try to start it, it gives a lope or 2 of idle then dies. Please, does anyone have any idea what may be wrong?

Thanks.

Ha I know I wont be the one to be blamed for this fuck up

SyCK

Discussion Starter · #10 · Nov 2, 2001

Re: Re: VPC Hardwire help..(long)

G said:
Ha I know I wont be the one to be blamed for this fuck up

Hardy har har, either way, you're still not touching any electrical aspect of the car....

anthraciteboy

· #11 · Nov 2, 2001

No I have not tried to reverse it yet because i havn't had time and i want to make sure that it is the yellow wire that the afc must be tapped into and not the blue. Can you confirm this that the yellow is the output of the VPC.

Henry

SyCK

Discussion Starter · #12 · Nov 2, 2001

anthraciteboy said:
No I have not tried to reverse it yet because i havn't had time and i want to make sure that it is the yellow wire that the afc must be tapped into and not the blue. Can you confirm this that the yellow is the output of the VPC.

Henry

My understanding from what I have read, It goes... Input wire from Fuel controller taps into the YELLOW wire from the VPC then the Output wire from the Fuel controller goes to pin #66
If the Input and Output wires are reversed, you'll have no control over changing the fuel values.

anthraciteboy

· #13 · Nov 2, 2001

Thanks a lot I think i am sure that i have it on the blue wire. I will tap it into the yellow tonight and let you know if it works.
Thanks again
Hope that you get your wiring all figured out also.

Henry

G

· #14 · Nov 2, 2001

What yellow?

i have it on the blue

witch one is it my car is running right know but with the cam's i just installed it smell like raw fuel.

thanks
augie

anthraciteboy

· #15 · Nov 5, 2001

Well here is the scoop. I wired the input side of the fuel controller (white for S-AFC) into the VPC side of the YELLOW wire and the output of the Fuel Controller (yellow for S-AFC) to the ECU side. The yellow wire i used was the yellow wire coming directly from the VPC. It is right next to the blue. Well I wired this up and MY CAR DID NOT START, so I knew that this was the wrong wire. Then I called up Kean and asked him to help me with the problem. We ended up tapping the wires from the fuel controller directly at the VPC harness. The pin wire I used was B-66 which is for the mass air meter. I figured that this wire has to be the output wire of the VPC since it is tapped into the harness. If you look at the B-66 of the VPC harness there are two wires split from this pin. One wire goes to the original harness and the other wire goes to the VPC unit itself. I used this wire to tap the S-AFC wires into. The input side of the AFC which is the WHITE wire goes toward the VPC unit and the YELLOW wire of the S-AFC which is the output goes toward the ECU. I started the car and it started fine. My egts did not get over 800C but I have to put it back on the dyno to see if i can control the fuel curve. If I can then the problem is solved. Thanks to all who helped me with this problem. I keep yall up to date on the dyno results with the new wiring.

Henry

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anthraciteboy

· #16 · Nov 5, 2001

OH yeah I forgot to mention that i had it tapped into the blue wire at first. The car ran fine but i could not adjust the fuel curve. I wired it up how apexi has it on their website. I believe that the blue wire is the right one but the input and output is reversed on the apexi website. Input should be toward the VPC and output should be toward the ECU. The way apexi has it is opposite. I am not 100% sure but let me check this and let everyone know what the deal is.

Henry

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