Again With The Hesitations! :o(
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Again With The Hesitations! :o(
Over the last several months I've asked this a few times and have been slowly [in spare time from work and school] narrowing it down.
A breif over veiw [since I've posted it before] car hits a 'rev limiter' at high RPM- normally right around 5000-5500. The only other time it does it is if I get on it hard in low RPM. Ex: 4th gear, 30mph, 2000RPM it will hit the 'fuel cut / rev limiter'. This is a 5AT.
Here is where the plot thickens. If It hits the limiter I immeditately get off the throttle and shift. Sometimes when I go to even lightly get back on the pedal it will get the hesitation again and I have to back off and wait like 3 or 4 seconds and get push the gas pedal to get up to speed.
The SLIP light comes on, the CEL comes and the VDC won't turn on [VDC is always off, so if I push the button again the light won't go away].
I am throwing a code for Crankshaft Position Sensor, so I know I need to look into this [possibly sheilded?] My question now is, how is the SLIP light connected? I know its NOT loosing traction at 2000RPM and 40%-50% throttle. The hesitation is similar to what others describe, its violent, and can't be good...
I have the UTEC and want to datalog it and post it... but don't know how to go about doing that. Tried to follow the directions, but I'm to poosy afraid I'll mess my tune up. [unless someone wants to PM me even better instructions then what I got off TurboXS website.]
Thanks!
A breif over veiw [since I've posted it before] car hits a 'rev limiter' at high RPM- normally right around 5000-5500. The only other time it does it is if I get on it hard in low RPM. Ex: 4th gear, 30mph, 2000RPM it will hit the 'fuel cut / rev limiter'. This is a 5AT.
Here is where the plot thickens. If It hits the limiter I immeditately get off the throttle and shift. Sometimes when I go to even lightly get back on the pedal it will get the hesitation again and I have to back off and wait like 3 or 4 seconds and get push the gas pedal to get up to speed.
The SLIP light comes on, the CEL comes and the VDC won't turn on [VDC is always off, so if I push the button again the light won't go away].
I am throwing a code for Crankshaft Position Sensor, so I know I need to look into this [possibly sheilded?] My question now is, how is the SLIP light connected? I know its NOT loosing traction at 2000RPM and 40%-50% throttle. The hesitation is similar to what others describe, its violent, and can't be good...
I have the UTEC and want to datalog it and post it... but don't know how to go about doing that. Tried to follow the directions, but I'm to poosy afraid I'll mess my tune up. [unless someone wants to PM me even better instructions then what I got off TurboXS website.]
Thanks!
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I had what I believe to be a very similar problem with an APS TT and unichip. My shop spent a couple weeks trying to figure it out.
I really do not know enough to articulate the problem, but here was the explanation of the problem given to me by my shop (quote from email):
This problem had us baffled for weeks and we are still not sure exactly WHY this caused the problem, but it did.
I hope that helps.
I really do not know enough to articulate the problem, but here was the explanation of the problem given to me by my shop (quote from email):
...Next we moved on to the fuel map. There were no obvious "holes" there either. I did notice some strange abrupt changes that didn't make sense to me. The best example I could give you would be to count to 100 by 1's. Once you get to 87, the next number count 82 instead of 88, then count 89. Not a huge change, but definitely abrupt. I've seen this before on other peoples maps we've tuned. My rule of thumb has alway been to keep the map as smooth and transitional as possible. There were about 10 of these little outliers on your map, so I changed them. A map is 3-D, so think of it as a hill that your running down and suddenly the ground dips lower under you foot. Depending on how low that dip is or which direction your going, you may fall or just slow down. Well, I leveled the ground basically....
That's when I decided to take it out for one last run to see how my changes would effect the mapping. Can you believe the problem was gone?! The car made 9psi in 3rd, 4th, and 5th gears
That's when I decided to take it out for one last run to see how my changes would effect the mapping. Can you believe the problem was gone?! The car made 9psi in 3rd, 4th, and 5th gears
I hope that helps.
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Originally Posted by booger
My first guess [ you get a crankshaft position sensor code ] is your wiring is f-cked up . Or there is a issue with the Utec .
Dont know your motor history...is it built with cams ?
Dont know your motor history...is it built with cams ?
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The ONLY things done to the car are:
ProCharger, 7psi
UTEC [problem happened with GReddy EU also]
750cc RC Inj.
Walbro 255
SGP Return fuel syst.
Fully upgraded tranny and rearend
Why the huge injectors I don't know. They said I maxed out 380, then the 440s, so they put 750 in and said I'll never have that problem again [I would think!!!!]... those don't seem to be an issue, car idles pretty descent and on decel it gets alittle rich, but other then that they seem just fine.
So far to check off is the fuel pressure, Crank Sensor to see if those fix anything. [I'm thinkin maybe the large injectors were because the pressure is lower then normal?]
But any reason why the SLIP is comming up also?
ProCharger, 7psi
UTEC [problem happened with GReddy EU also]
750cc RC Inj.
Walbro 255
SGP Return fuel syst.
Fully upgraded tranny and rearend
Why the huge injectors I don't know. They said I maxed out 380, then the 440s, so they put 750 in and said I'll never have that problem again [I would think!!!!]... those don't seem to be an issue, car idles pretty descent and on decel it gets alittle rich, but other then that they seem just fine.
So far to check off is the fuel pressure, Crank Sensor to see if those fix anything. [I'm thinkin maybe the large injectors were because the pressure is lower then normal?]
But any reason why the SLIP is comming up also?
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Originally Posted by HomieG35
Again, thank you.
But what about the SLIP light. Thanks.
I've posted about this 4 times over the last few months... I've heard about the injectors 4 times...
But what about the SLIP light. Thanks.
I've posted about this 4 times over the last few months... I've heard about the injectors 4 times...
See my post above.
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I think i replyed to one of your old post. I had the exact same issue and what is happening is when you get that violent hesitation it is because the utec is going from a say 7psi fuel load site to a 20psi load site because of a software error which in turn dumps a ton of fuel and boggs it out. I confirmed this with my tuner while doing a street tune, so it is def. an error with the utec. I upgraded my software to v2.8 and havent had a problem since.
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