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Old 01-15-2011, 11:53 PM   #1
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Default TPS sensitivity, tripping accel enrichments, bucking.

My birthday is in a few weeks, and that means it's almost time to smog. I think I have a handle on how to get MS to pass as far as tuning goes, but I'm still having some difficulties getting a clean road tune. I just finished installing the PWM converter board, finally got closed loop working somewhat well. Problem comes with steady-state cruise, I was getting an awful nasty bucking (captured in the screenshot below)



After some head scratching, acceleration enrichment toying, IAC disconnecting, I finally disconnected the TPS. Aside from an awful lean tip-in, the bucking is gone. This is a 99 head, 99 throttle body + IAC and a 99 TPS spliced in (technically, I got them off a kia sephia, but its mazda stamped and from a BP engine).

Now - calibration in MS seems to be awful.. weird. Even after a calibration, my TPS can show between 7 and -3 with the throttle closed. It seems like at 10% throttle the TPS reads 40%. I've already re-done my grounds, swapped out the TPS for another junkyard kia. Could I have made a mistake in wiring? Going from the 5 wire 94 to the 3 wire 99, I couldn't go by wire color because the Kia uses different wire colors.



Can anyone take a shot of their TPS wires so I can figure out pin position? and am I correct in assuming that red/black is the 5v vref, and the wiring should be

94 - 99
black/red - red/black (vref?)
lt green/white - green/black (tps signal?)
blk/blu - lt grn/red (ground?)

Other relevant details:
94 1.8, 99 head + intake
ms2 3.0.3u, v3 board (self built), sequential injection
jbperf p&h, pwm converter

including my very dirty msq - if anyone would care to comment on any obvious errors (fuel and spark is pretty close to default mspnp, closed loop idle is working but still pretty rough), I'd be thankful.
Attached Files
File Type: msq bucky.msq (78.6 KB, 68 views)
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Old 01-16-2011, 07:17 PM   #2
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Managed to score another TPS from pullapart today. between pins 1 and 3 on the old TPS i'm getting 26ohms open, 3.7k ohms closed. The new TPS is 20ohms open, 3.8k closed. The analogue portion of my multimeter (Fluke 87) is showing a very linear sweep, doesn't appear to be any deadspots.

The kia colors are

pin1 - green
pin2 - black/yellow
pin3 - green/red

I checked my pin outs on my TPS connector

pin1 - +5v
pin2 - ground
pin3 - signal

Looking at the MS schematics, should I be checking C8, C9 and R9? Maybe bumping up the capacitance on C9?
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Old 01-17-2011, 06:51 PM   #3
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I pulled the board and noticed that some of the solder around c8 and c9 were subar, refluxed and resoldered. Tossed the new TPS on the car as well, but none of that made any difference. I changed over to mapdot and I can finally tune cruise now, so my immediate issue is solved.
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Old 01-18-2011, 10:37 AM   #4
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turn off launch control.
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Old 01-18-2011, 11:01 AM   #5
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Quote:
Originally Posted by bittetech View Post
I pulled the board and noticed that some of the solder around c8 and c9 were subar, refluxed and resoldered. Tossed the new TPS on the car as well, but none of that made any difference. I changed over to mapdot and I can finally tune cruise now, so my immediate issue is solved.
Do you see erratic TPS values while cruising? Kind of looks like TPS is all over the place in the screen cap below.
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Old 01-18-2011, 09:44 PM   #6
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Brain: <facepalm>... thanks. Should've realized that.

Ben: Here's a mapdot cruise ~2500rpm with a 3psi poke at the end. It still looks a little erratic, but at least its not bucking.

Lemme go turn tpsdot back on with launch control off and grab a log.
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TPS sensitivity, tripping accel enrichments, bucking.-graph3.png  
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Old 01-19-2011, 02:15 AM   #7
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no luck turning off launch control. With TPS ae turned back on, the bucking returned. Went back to mapdot and did some more ve analyze live tuning. Here's a long steady state cruise, and another log with some really weird RPM bouncing. There doesn't appear to be a lost sync event that correlates though - I do occasionally get them, looks like I had 10 in the course of a 1 hour drive.
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TPS sensitivity, tripping accel enrichments, bucking.-graph4.png   TPS sensitivity, tripping accel enrichments, bucking.-twitchy.png  
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Old 01-19-2011, 11:18 PM   #8
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Feeling brash I had the car smogged today, eeked by with 1242 with 1242 allowed in nox in the 15/50 test. So with that out of the way, I have a year to focus on getting MS3 and crank trigger working.
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