Quick rundown

Obd1 Sc300 auto
EBay mani, 50mm wg 12psi spring
EBay t70
Egr delete w/resistor no cel
Walbro255
660cc inj
Tt HG ,arp head studs
Auto trans ext trans cooler
SafcII
HKS vpc w/mkiii 550 chip
Maf delete w/resistor no cel
New gaskets,seals,etc..

So car was tuned last fall on safc2 8psi made 276whp with dist retarded 4 degrees..

This winter torn down motor HG install bigger inj's fuel pump etc..HKS vpc and ready for a tune this coming sat.

The car runs it was going to 10 on the wideband cause of 660's vs 330 stock inj's so I took out about -30% fuel with safc and the idle **** on vpc about 3 clicks counter clockwise to lean it out now it idles around 14.5-15.0

The only problem I'm having is if I mash the gas the car will bog and want to die if I don't let off the gas. But I can lightly bring up the throttle to redline if I want,I never removed the tps sensor during the build only unplugged it,so I ruled that out..

Boost gauge shows -20 when idling so I have good vacuum.
I've checked couplers,clamps,vac lines and sources can't find any leaks.

Could a faulty temp sensor from the vpc cause any of these symptoms?

I've unplugged the vpc map sensor vac hose while idling and the car died..I haven't tried unplugging the temp sensor tho to see if that would make the car die.

I have a mkiv chip for vpc and a mkIII I tried both chips.. the mkIII chip the car runs as stated, the mkiv chip car will not even start..

I'm lost if anyone has had experience in this area please help a brother out ..!! Thanks-chad

 

Ah yes the Good ole VPC, I remember these things.

The VPC needs both MAP and Temp to give you an output signal, so your guess on the temp sensor is good.

Get a GM temp sensor as the HKS VPC ones are dis-continued.

 

good luck.

 

I think you have WAY too much fuel for what HP you can safely make without exploding your transmission. You have low CR and lots of fuel.

You are limited to 350 ish on the stock trans, and your setup is for slightly more than that.

-30% fuel is way too much to pull. I pull -8% at full boost on stock EVERYTHING. Im running 11 psi and I make 347/337.

Good luck....

 

I'm gonna check the vpc temp sensor unplug it while car is running see what it does,also grab the multi meter and check voltage at temp and map and tps make sure those are all within spec..

I am setup for much more HP than my stock auto will hold true...
But I'm planning for around 350whp and if and when the auto takes a **** on me I have a jdm tt auto waiting,swap valve bodies install sc4 drive shaft and crank up the boost to no more than 17psi and that should put me around 400whp

So first things first get this damn thing running right,then worry about the trans

 

My point has been all along that you overbuilt for what you plan to do.

We have essentially the same setup and I make 350 on a full stock engine at 11 psi. Stock fuel pump, stock injectors AND im still running a MAF until i get unlazy and install a VPC i have laying around.,

Having the low compression like you do and running that low of a boost level will make you hate your driveability, unless you like having a laggy turbo, I feel like mine lags a bit... so i cant imagine yours. Even when you get to 17 psi, it may get better... you are just gonna hate your spool.