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Discussion Starter · #1 · (Edited)
My car is scurred up.....i real need help. I have been in and out of the shop and am getting annoyed. It has something to do with the s afc and vpc i have. the car also has t 78, fmic, and fuelpressure regulator. I am running real rich and stalling out. the shop replaced the pressure sensor and the car ran fine for about two trips and now its dead. please could some one come help. I am in the boca raton area.
 

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Tried checking the voltage on the MAP sensor? Was it the stock or VPC MAP sensor that was replaced? Make sure the MAP sensor is mounted with the vaccum hose nipple facing downward. This will be hard to find a spot for, but it's ideal. Keep hosing to a minimum and make sure the VPC isn't T'd off with any other vaccum hoses from other accessories. Check the voltage on your VPC map sensor (has to be done from right behind the control unit) and from your stock TPS and MAF sensor (These can be checked easily via the AFC). Reference the TSRMs and VPC troubleshooting page for the correct voltages. You may want to try pressurizing the system to check for any vaccum leaks.
 

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Discussion Starter · #5 ·
Ok so i checked some of those things (don't have a multimeter). And the sensor that the shop told me was the MAP senor that they replaced has the nipple faced upward. Also the hose is about 2 ft long and T'd off along with other hoses that are T'd off another 2 times (about 6 in all). Also one of the hoses is connected to this part that is driven by a pully under the throttle body. Pics will be up soon

Thanks Sherbaz for the for the shop reference and help over the phone. We'll work that out this week. Now get tuned up and keep that beast of a car in hiding until its time to come out and play :)
 

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Discussion Starter · #6 ·
The sensor with the vacum hose coming out the top is the one they said they replaced. If it is then according to a bunch of people, it shouldn't be pointed up.



Two of the Three T fittings.....




One of the hoses leads to this attached to the pulley, under the IC pipe....

 

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Yeah, that's the sensor. It needs to be facing downward. You may have to get creative in re-routing your vaccum lines so that the VPC MAP sensor line is as uninterrupted as possible.
 

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VPC is garbage, there is a reason why they discontinued it.. I talked to my friend and he will contact you tomo.. Hang in there till tomo.

Sherbaz
 

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Troux - glad we got your VPC problems sorted out, you've learned a lot about it after all that mess!


Turbo4reek - got your PM, here is my response:
- Is your fuel pressure 41psi with the car running (with vacuum at idle), and if so is it 41 psi with or without the vacuum hose attached?
- Zero out all the VPC knobs and any idle/low RPM correction on the SAFC. This is one of the most common screw ups I see. In closed loop at low RPM, the OEM ECU will 'fight' the VPC settings to achieve a target o2 sensor feedback.
- On ONE vacuum source (POST-throttle body) route the hoses as short as possible so that the HKS VPC MAP sensor, the OEM MAP sensor, and the adjustable fuel pressure regulator are all on one source. Route other devices (boost controller, boost gauge, etc) on another vacuum source.
- Reset the ECU by pulling the #1 EFI fuse for 30 seconds
- After you respond the my question about your fuel pressure and we make sure that's OK, THEN change your plugs, as they are probably fouled badly after going through all of your recent problems.
 

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Discussion Starter · #11 · (Edited)
JeremyBlackwell said:
Turbo4reek - got your PM, here is my response:
- Is your fuel pressure 41psi with the car running (with vacuum at idle), and if so is it 41 psi with or without the vacuum hose attached?
- Zero out all the VPC knobs and any idle/low RPM correction on the SAFC. This is one of the most common screw ups I see. In closed loop at low RPM, the OEM ECU will 'fight' the VPC settings to achieve a target o2 sensor feedback.
- On ONE vacuum source (POST-throttle body) route the hoses as short as possible so that the HKS VPC MAP sensor, the OEM MAP sensor, and the adjustable fuel pressure regulator are all on one source. Route other devices (boost controller, boost gauge, etc) on another vacuum source.
- Reset the ECU by pulling the #1 EFI fuse for 30 seconds
- After you respond the my question about your fuel pressure and we make sure that's OK, THEN change your plugs, as they are probably fouled badly after going through all of your recent problems.
- There is no way to tell if it is at idle b/c the car doesn't even start, it just cranks and cranks, but doesn't turn over. There is 41 PSI when cranking tho. The Vacum hose wasn't initially attached when i first got the car, but after i had the new sensor put on, the shop put a hose on and T'd it into the hoses on the manifold.

- I can zero out the nobs on the VPC, but i am unsure of what setting you're refering to on the SAFC with the Idle/low RPM correction

Also, what other source should i tap into for the other stuff, right now everything is tapped into the source next to the FPR.

P.S. I read that you need to use a 1200ohm resistor on the MAF Harness if the unit is hardwired. If this is true, then which wire do i use it on because i dont' think i have one.

Thanks for all your help

Josh
 

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what is fuel pressure with the car switch ON, but not cranking it?

on the SAFC, i was just saying in case someone tuned it below ~4000rpm to zero it out.

there are other vacuum sources you can use on the driver side or back of the intake manifold.

if i remember correctly off the top of my head, the AIT sensor is the pink/blue wire and the brown wire on the MAF plug, but DOUBLE CHECK that before doing it...
 

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You should pull the codes and work it from their . The codes should point you in the right direction , also check your safc settings . The code for your AFM is 31 and your SAFC should be set on hot wire not pressure . Your SAFC settings should look like this .
-Go to [main] ~>[setting] ~> [3. TH-Point] ~> [Lo-94, Hi-95]

-Go to [main] ~>[etc.] ~> [1. Sensor Type] ~> [1. Hot-Wire] ~> [in-12, Out-12] ~> [in-1, Out-1]

-Go to [main] ~>[etc.] ~> [2. Car Select] ~> [Cyl:6, Thr: UP]

-Go to [main] ~>[etc.] ~> [3. Graph scale] ~> [Ne = 7000rpm]

[Ne-POINT = 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000]
Good luck
 

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Discussion Starter · #15 ·
OK so i got my car to TPS in West Palm. And it was the way that the VPC was wired to the SAFC. The VPC was sending a reading to the SAFC sensor input that was suppose to be the reading from the stock sensor. So the VPC was altering the signal (which should have been a stock sensor reading, but it wasn't) b4 it got to the SAFC and the SAFC was getting a bad reading and as a result made me run like crap. Anyway i had both the VPC and SAFC re-wired and a couple of other minor things done.

After a Dyno tune.....

450whp at around 13:1 A/F Boost is at around 16psi

Mods:

T78
Stock fuel
SAFC, VPC, Profec B
Greddy FMIC
 

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Whoa there, richen up that air:fuel ratio!! You need the extra cooling provided by the extra fuel at that kind of power on 93 octane to help prevent pre-ignition and detonation. I'm sure at 13:1 you are getting a good bit of knock and timing retard. Running that lean will increase engine temperature and burn much slower than a richer mixture, leading to more chance of detonation. Leaner is not always better as far as power goes. That is one of the biggest internet myths. You actually have a fairly broad range of acceptability with air:fuel ratios that won't affect power a whole lot (as long as you have no timing retard, that is.) The most important factor in the amount of torque your engine produces is having full timing advance with no retard due to knock!
 

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Discussion Starter · #17 · (Edited)
I was thinking that it was a little lean. Right now i am at 38PSI fuel pressure. I was going to head back to the shop this week and ask them to bring the A/R down a bit (around 11.5-12, to keep it on the safer side of things). I was in a rush when i picked the car up and needed to get back to work, so i didn't see it.

P.S. I did have the EGR removed. That would account for the lean condition i think.
 

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If you have your EGR removed, you might want to drive the car around for 50 miles or so before dyno tuning so the ECU can re-learn your car's set-up (I recommend this for any car that's about to dyno tune...)

Also, you might want to consider bringing your air/fuel down to around 11:1 for safety reasons on 93 octane, especially with it being so hot out....11.5 to 12 is better suited for 116 octane to prevent detonation/timing retard. But, every car is different, so monitor your knock and go from there.
 

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Sherbaz said:
VPC is garbage, there is a reason why they discontinued it.. I talked to my friend and he will contact you tomo.. Hang in there till tomo.

Sherbaz
Right... HKS realized they made a big mistake with this product. That's also why you see so many up for sale now.
 
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