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Please check this datalog.....TPS goes wack in 4th?

Posted: Wed Jan 13, 2010 2:46 am
by hiperformance
This datalog was taken during a pass on the drag strip. The car started lunging and running bad for a little bit in 4th then it cleared and pulled strong again. From the point of shifting into 4th the gas pedal was pressed to the floor and never lifted. The datalog shows the TPS fluctuation? starting at 18.5 sec until 23 sec. Then by its self it goes back to normal, which is 97%. TPS sensor going bad? any ideas.


Posted: Wed Jan 13, 2010 9:18 am
by fly_n
Crikey Mate!
That whole datalog is just chaos,but very entertaining....thx for posting

That must be one long drag strip u got there,i'd get politely asked to leave if i kept accelerating that long at our local strip lol.... after they finished towing me outta the sandtrap of course....

That would be one quick little vehicle if u could introduce the tyres to the road,the 2 just dont seem to be agreeing with one another atm.
I'd probably knock another 5 pounds off 1st & 2nd if your gonna persist with trying to flat shift that thing or find some bigger rubber.
Whats with the bouncing the limiter for 2 secs at the top of 1st???

Also warm the motor a bit better before u run next time if u can or remove any of the low coolant temp devices u have installed,the whole run was done on like 20% extra fuel,im sure u didnt spend all that time tuning just to have that occuring in the background?

Which leads to u losing your injectors at 20 pounds at the top of third. Even without the 20% extra fuel,i'd probably think your running close to the time for an injector upgrade....

Now....what was the original problem?
The TPS is stuttering the whole run,so if its not u getting thrown around the cabin amidst all the chaos,my guess is u have a loose/bad connection on the TPS wiring somewhere,probably close to your highly vibrating motor, with all the wheelspin & limiter bouncing just highlighting the problem further.
Check your connections thoroughly before throwing cash at a new sensor.

Btw,post a vid of your next run,would luv to see it for real

Posted: Mon Jan 18, 2010 3:12 am
by hiperformance
The length of the data log is interesting. On that particular pass the car ran a 10.9 quarter mile. I had been mentioning to the driver that his shifts were a bit sluggish, I think he is traumatized by bad down shift mishap in the past. On the 1 to 2 shifts, you can actually see the front of the car dive. Thanks for taking a look, sometimes others can see what one can easily over look.