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View Full Version : SR20 Part Throttle Breakup

pacotaco345
04-23-2014, 11:16 AM
So I'm having a little driveability issue with my SR. Current setup is:
Blacktop S13 SR
Poncams (256)
S14 bbT28
Z32 MAF
FMIC
SARD/Denso 550cc injectors
Stock FPR
Walbro 255
3" exhaust all the way back
Enthalpy ROM tune

The issue happens whenever I'm between 1/3 to 2/3 throttle building boost with RPM. Full throttle the car will peg the tach with no issues but if I'm babying the throttle it will start to hesitate around 3.5-4k. At first I thought it was a timing issue since the car was previously tuned on a SAFC NEO but now that I have a ROM tune I'm more or less stumped. By no means does this issue make the car un-driveable but it sure would be nice to have that area of the throttle to use for on ramps, mountain roads and things like that. If anyone has an idea of what this could be let me know. Thanks.
jr_ss
04-23-2014, 11:57 AM
TPS adjustments are where I'd start. Sounds like a dead spot.
pacotaco345
04-23-2014, 02:29 PM
TPS adjustments are where I'd start. Sounds like a dead spot.
Does TPS affect anything other than idle? When I check the voltage with my SAFC it reads withing the correct parameters.
TwoForDeh
04-23-2014, 02:51 PM
i had the exact same issue and it was a combination of my TPS and a vacuum leak. it would sputter a under light load/maintaining speed but if i pressed the gas just a bit more, it would stop. Just an idea man!
pacotaco345
04-24-2014, 03:18 PM
i had the exact same issue and it was a combination of my TPS and a vacuum leak. it would sputter a under light load/maintaining speed but if i pressed the gas just a bit more, it would stop. Just an idea man!

How do you adjust the TPS? I know there's a min and max voltage that it should output (and mine does output the correct voltages), but how do you fine tune everything in between?
TwoForDeh
04-24-2014, 03:21 PM
you gotta leave it plugged in and probe it from the back...heh heh..i believe its the middle pin. with the ignition on, you should be getting .45v when it's closed and upper 3's? at open? i think? if its off, there's 2 small bolts on the top and bottom where you can loosen them and rotate it (kinda like a distributor or CAS is setup)