Go Back   Truck Forums > Chevrolet/GMC Truck Forums > Chevy Silverado/ GMC Sierra Forum
Sign in using an external account
Register Forgot Password?
Search

Reply
 
 
 
 
LinkBack Thread Tools Search this Thread
  #1  
Old 11-20-2009, 09:33 PM
Junior Member
 
Join Date: Nov 2009
Posts: 4
Default Silverado studder/hesitation, bad acceleration

Ok heres the deal, i have a 2000 silverado 2500, its the new body stlye with the 6.0 and the 4l80e transmisson. I recently did a motor swap to a lower mileage motor. Ive worked out most of the bugs but this last one is starting to **** me off. If your at a light and you floor it it runs to about 50 and the rpms continue to rise but will never switch gears until you back off the gas. Its reading no codes except 160 and 140. Both are rear o2 sensor codes so i know those have nothing to do with it since they dont affect fuel/air ratio.
What ive done so far.
-fuel filter
-plugs, wires and coils all 8
-map sensor
-cam sensor
-crank sensor
-mass air flow sensor
-coolant temp sensor
-cleaned throttle body and new intake
-IAC valve
-TPS sensor
-knock sensors

Im stumped i dont know where to go from here, should i of had the ecm flashed when i did the motor swap? its the same motor and tranny but from a different year.

Anyone have an idea???
This ad is not displayed to registered members.
Register your free account today and become a member on Truckforums!
Reply With Quote
  #2  
Old 11-20-2009, 10:16 PM
chrisbmo2000's Avatar
General Truck/Classifieds Forum Moderator
 
Join Date: Jan 2009
Location: Columbia, Mo
Posts: 984
Default

sounds like you have a shift problem assuming that you set the TPS right...........i would have a tranny shop look at it....the 4l60e the (4l80e's little brother) has the same problem when they start to get over about 80,000 miles on them.....does it shift at all? or does it stay in first gear?? My advice is have the tranny checked out or change the fluid and filter first....my money is on a tranny problem
__________________
CHRIS
97 Suburban
Descreened MAF
Turned up EPC
Blacked out Grill
New Motor
Tranny built for pulling
My Photos
http://s561.photobucket.com/albums/ss55/chrisbmo2000/

10/23/10 Believe it!!! Mizzou beat Oklahoma
Check out the Truck of the month, nominate and VOTE !!!!!!!!
PM me or any of the other Moderators if you need anything
Reply With Quote
  #3  
Old 11-21-2009, 06:02 AM
Senior Member
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 208
Default

After the motor swap was the crankshaft variation relearn done? If not I would do this before anything else. You may have to have the dealer do this with the scan tool. Dont know if a aftermarket one will have the function?
Reply With Quote
  #4  
Old 11-21-2009, 10:02 AM
Junior Member
 
Join Date: Nov 2009
Posts: 4
Default

Is it necessary to adjust the tps sensor? I didn't think that trucks sensor was adjustable. How do I adjust it?
And what about the crankshaft variation. Explain to me what that is.

And ive also flushed tranny, and dropped the pan and changed the filter

Last edited by Townjester23; 11-21-2009 at 01:13 PM.
Reply With Quote
  #5  
Old 11-21-2009, 08:24 PM
Senior Member
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 208
Default

The crankshaft position (CKP) sensor is mounted in the front of the engine behind the harmonic balancer. The CKP sensor works in conjunction with a 3X (4X on V8 applications) reluctor wheel mounted on the front of the crankshaft. The CKP sensor has a B+ power supply, a ground, and a signal circuit.

As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet located in the sensor. The sensors internal circuitry detects this field and produces a frequency which the control module monitors on the signal circuit. The control module uses this signal in order to accurately measure crankshaft velocity, which is important to ignition control spark timing, fuel injector timing, and for misfire detection.

The control module can detect small variations in the CKP sensor and reluctor wheel. These part tolerances must be learned by the control module before an accurate CKP signal can be determined. At high engine speeds, slight variations in the following components make misfire detection difficult:

Crankshaft

Reluctor wheel

CKP sensor

The control module learns variations during the Crankshaft Position System Variation Learning Procedure, and compensates for these variations when performing misfire calculations. Only a scan tool can command the control module to perform the Crankshaft Position System Variation Learning Procedure.

Perform the learning procedure after the following actions:

A control module replacement

Any operation or repair involving the crankshaft, the CKP sensor, or the CKP sensor to reluctor wheel gap relationship

An engine replacement
Reply With Quote
  #6  
Old 11-22-2009, 01:16 AM
Junior Member
 
Join Date: Nov 2009
Posts: 4
Default

My make and models crankshaft position sensor is located behind the started, no the harmonic balancer. Its also new. I talked to gm today and they said that if i unplugg the cam sensor, crank sensor, ecm, motor swap etc...Its gonna throw off the timing somehow. He also said that it more than likely wont throw a code(MIL INDICATOR) until ran on a diagnostics machine. Ive already replaced EVERY sensor on the 6.0 liter beast so this has got to be a computer issue.

I do appreciate all the help yal have thrown my way, Ive been inside and out on theses motors and trannys so feel free to throw any issues at me -Townjester23
Reply With Quote
  #7  
Old 11-22-2009, 05:56 AM
Senior Member
 
Join Date: Jun 2008
Location: New Hampshire
Posts: 208
Default

Exactly!!! It will throw the timing and fuel values off until you (Time it) run the crankshaft varaition relearn. This is running on the old engines values. If your old motor say had a loose timing set and you put a new motor in with a tight chain and dears you will still be running of the old engines timing values. This procedure has been around since 1998. I looked at your first post on all the sensors you have replaced. Did you torque the knock sensors when you replaced them? I have seen if they are over torqued they get too sensative and will retard the timing quicker without setting a code. Are all the grounds for the pcm clean and tight? Just a thought. But I still think your problem is in the Crank Variation.
Reply With Quote
  #8  
Old 11-25-2009, 10:28 PM
Junior Member
 
Join Date: Nov 2009
Posts: 4
Default

Well this is great, now ive got a po300 multiple cylinder misfire. Crappy gas mileage, poor performance. going to the dealer next week to reflash the computer and and do the crankshaft variation.
Reply With Quote
Old 11-25-2009, 10:28 PM
 
 
 
Reply



Tags
2000, 2500, 60, 97, acceleration, chevy, crappy, hesitates, hesitation, liter, mileage, o2, problems, sensor, silverado, studders, timing

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Advertising

Featured Sponsors
Vendor Directory

Our Sponsors
Advertising
All times are GMT -5. The time now is 08:20 AM.

Internet Brands, Inc.



SEO by vBSEO ©2010, Crawlability, Inc.