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DaveH disciple
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Discussion Starter #1
Hi ! Today, I put on my HKS VPC for my 1995 NA-T setup... After adjusting idle, I've decided to go on the road to do a little test...I was surprised when the boost going up....BIG HESITATION, can't boost.....Was like sparks u know.....

I decided to install my last setup (LS400 maf) to check if the problem was from the car or the VPC and all was OK.....Going up to 16 psi......

What's that f.u.c.k.i.n.g problem guys ???? According the VPC manual, could be the pressure sensor.....I didn't do a test yet on this sensor but I'll probably doing one really soon....

JB
 

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King of the NA-T's
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4,044 Posts
What was the a/f ratio doing? Was the AFC still adjusted as previously, or was it zero'd out?
 

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This is the same prob the other guy is having... Where did you get your VPC, your chip, how did you wire it, blah blah blah. Search works- just keep at it and it will return 475 posts on this subject.
 

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DaveH disciple
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368 Posts
Discussion Starter #6
MtFujiSupra said:
Wanna bet?
Hi ! I've bought it from DaveH and sure the VPC is probably at 99.9 % good u know....The wiring have been double checked via the DaveH diagram and Kirk (clubna-t.com) diagram too..... The idle knob is at 9 o'clock and all others ones are at 12 o'oclock.....

I didn't reset my AFC-II but i'm not sure this big hesitation when my turbo is spooling come from of my AFC-II........I'll re-install my VPC today and check what's my wideband could tell me on the A/F......

JB
 

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DaveH disciple
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368 Posts
Discussion Starter #7
I've checked my pressure sensor and all numbers on the voltage are similar to the check chart..... My car is extremely too rich ; like 7.4/1 when boosting u know.....

My question is could it affect the VPC until do big hesitation like this ???? My LS400 maf boost 16 psi at 7.4/1 without any problems u know....

JB
 

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There is no "street-level" AFR device that I know of that reads down to 7:1 with accuracy? Tell you what, you go ask V8killer what to do with that S-AFC.
 

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DaveH disciple
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Discussion Starter #9
Hmmm it's an innovate wideband man....don't know what's the minimum numbers on theses wideband......
 

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Do you have any CELs on right now? If you have not placed the 1200ohm resistor in the maf you will be running extremely rich.

if there are no CELs on how long did you drive the car around for. Whenever I reset my ecu I have a big hesitation also for the first 20min of driving then the car will clear itself up.

Also you want to make sure that you have the right chip in the vpc and you did not initially put it in the wrong way. If the chip was placed backwards there is a good chance you fried it.

carlo
 

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DaveH disciple
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368 Posts
Discussion Starter #11
balticMKIV said:
Do you have any CELs on right now? If you have not placed the 1200ohm resistor in the maf you will be running extremely rich.

if there are no CELs on how long did you drive the car around for. Whenever I reset my ecu I have a big hesitation also for the first 20min of driving then the car will clear itself up.

Also you want to make sure that you have the right chip in the vpc and you did not initially put it in the wrong way. If the chip was placed backwards there is a good chance you fried it.

carlo
Hi ! I've no ERROR CODES on the car and drive it only 3-4 minutes cause I got a big hesitation when I tried to get boost.....
According DaveH, I should reset my AFC-II an re-tune it.... The VPC is from him and sure he sold me good parts u know.... I never move the chip in that VPC and sure that my installation is OK cause I've used 2 differents installation sheet (both are the same instructions) and my wiring are probably OK.....

I tested my pressure sensor and the voltage is OK....

According my innovate wideband write-up, it's possible to read a 7.4/1 ratio on this wideband....

JB
 

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lelou21 said:
Hmmm it's an innovate wideband man....don't know what's the minimum numbers on theses wideband......
I don't have a clue dude, but 7:1 is stupid rich and the UEGO is not calibrated down at that level.

Being able to display is not the same as reporting accurate numbers.
 

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lelou21 said:
Hi ! I've no ERROR CODES on the car and drive it only 3-4 minutes cause I got a big hesitation when I tried to get boost.....
According DaveH, I should reset my AFC-II an re-tune it.... The VPC is from him and sure he sold me good parts u know.... I never move the chip in that VPC and sure that my installation is OK cause I've used 2 differents installation sheet (both are the same instructions) and my wiring are probably OK.....

I tested my pressure sensor and the voltage is OK....

According my innovate wideband write-up, it's possible to read a 7.4/1 ratio on this wideband....

JB
Did you solder all the wiring? If not I would solder all the connections and triple check to make sure you wired everything correctly.

Double check to make sure the SAFC settings are all correct also. Try driving the car around longer than for 5min and see if the symptoms clear up. The ecu needs some time to adjust.
 

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DaveH disciple
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Discussion Starter #14
Hey hey ! I've done an other test : resetting ECU and drive like 25-30 min....
The car had a better feeling but not much....
What i'm thinking, it seems to be like a boost spike u know cause i've a profec type-S BC and could adjust "gain"....
The problem is only when boost up u know cause the car run nice (but too rich for sure...)

I couldn't understand when it happen only with the VPC ON cause i'm still running the profec type S on the ls400 maf and all is perfect.....

JB
 

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DaveH disciple
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368 Posts
Discussion Starter #16
balticMKIV said:
do you have a fuel system? what vpc chip do you have?
Yess dude, walbro 255 lph fuel pump, 525cc injectors, 2mm HG, ARP head studs, etc....

I've the MKIII 550 cc chip....The right one for obd 1 NA-T.....

JB
 
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