shifts at 3500
Last edited by william43; Mar 3, 2013 at 06:22 PM.





You should EASILY be able to hit 6000 RPM without fail. Somethings rotten in Demmark.... First and most IMPORTANT is for you to read and post your DTCs. Heres how you do it:
READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)
This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.
Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.
If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.
These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs
Here are some very good sites that explain what DTC mean:
http://www.gearchatter.com/viewtopic11755.php
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix when you post your DTCs!!
NEXT! Check your AIr Filter and make sure that it is clean and DRY.
NEXT! When was the last time you changed the Fuel Filter? May be clogged.
The DTCs are the most important.
1. What engine modifications do you have done?
2. When was the last time you changed the plugs and wires?
3. Do you see any DIC Messaged or lights on the IPC?
Bill
You should EASILY be able to hit 6000 RPM without fail. Somethings rotten in Demmark.... First and most IMPORTANT is for you to read and post your DTCs. Heres how you do it:
READING YOUR C5 Engine Diagnostic Trouble Codes (DTC)
This procedure should be carried out any time you experience a problem with your C5. Most inexpensive store bought aftermarket code readers will ONLY read power train DTC’s. Reading the DTC’s with the C5 built in code reader will allow you to read ALL the modules in the vehicle.
The Diagnostic Display Mode is entered with the following procedure:
1) Turn on the ignition but don't start the engine.
2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold the OPTIONS button
4) While holding OPTIONS, press FUEL button four times within a 10 -second period.
Initially, the on-board diagnostics go into an Automatic Mode which will cycle through each module and shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each module. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two types of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current code indicates a malfunction is present in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes. More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except E/M. Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press RESET To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles. There are a few body module DTC’s that if set will prevent the module from operating properly. Once the DTC is cleared, the module will return to full function. This is not true for power train DTCs.
If you have never read and cleared your codes, there will probably be a lot of old history DTCs. It is recommended that you clear your codes and see if any come back during a driving cycle. Those are the ones that you need to concentrate on diagnosing.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5.
NOTE and a WARNING. You can read the DTCs while the engine is running. I pull mine up all the time while driving.
WARNING. Don’t become distracted while reading DTCs while your driving and cause an accident!!!!! Use common sense and drive safe.
These are some very good C5 Diagnostic Trouble Code (DTC) explanation web sites!!! They also explain how to read the DTCs
Here are some very good sites that explain what DTC mean:
http://www.gearchatter.com/viewtopic11755.php
http://www.obd-codes.com/trouble_cod...d-ii-codes.php
Make sure to include the H or C suffix when you post your DTCs!!
NEXT! Check your AIr Filter and make sure that it is clean and DRY.
NEXT! When was the last time you changed the Fuel Filter? May be clogged.
The DTCs are the most important.
1. What engine modifications do you have done?
2. When was the last time you changed the plugs and wires?
3. Do you see any DIC Messaged or lights on the IPC?
Bill
Also--What is the coolant temp ? There is a cold engine RPM limiter based on coolant temps--If your temp sensor is not working the ECM may think the engine is not warm-- Depending on year the cold eng RPM limiter is set like 3000-4500
Also--What is the coolant temp ? There is a cold engine RPM limiter based on coolant temps--If your temp sensor is not working the ECM may think the engine is not warm-- Depending on year the cold eng RPM limiter is set like 3000-4500
The Best of Corvette for Corvette Enthusiasts
Do NOT discount the codes with the H following them. They can provide an audit trail for issues going on with the car. They ARE important in diagnosing problems.
Post ALL the codes that you pull with the engine running..........
Some codes go away WITHOUT setting an H code when you shut the engine off. I suspect you will have several codes that will show C or HC that do NOT show when the engine is turned off.





1 Has anyone TUNED or REFLASHED your PCM?
2. Do you see ANY messages or warnings on the DIC when it happens?
Some things that you need to check!!!!
Find the FUEL PUMP FUSE in the engine compartment fuse box. On top of each fuse are two small test points. Obtain a DC VOLT Meter and read both of those test points to chassie ground (The ignition Switch will nee to be in RUN to read the voltage)
You should see full battery voltage. Compare that reading with the reading that you get reading directly on the battery terminals. Should be the same.
If that reads good,, you need to monitor your fuel pressure on the fuel rail. If the pressure drops off below 60 PSI ay WOT,, you have a fuel supply issue. Pump, Power supply, pinched line, dirty clogged filter etc etc....
1 Has anyone TUNED or REFLASHED your PCM?
2. Do you see ANY messages or warnings on the DIC when it happens?
Some things that you need to check!!!!
Find the FUEL PUMP FUSE in the engine compartment fuse box. On top of each fuse are two small test points. Obtain a DC VOLT Meter and read both of those test points to chassie ground (The ignition Switch will nee to be in RUN to read the voltage)
You should see full battery voltage. Compare that reading with the reading that you get reading directly on the battery terminals. Should be the same.
If that reads good,, you need to monitor your fuel pressure on the fuel rail. If the pressure drops off below 60 PSI ay WOT,, you have a fuel supply issue. Pump, Power supply, pinched line, dirty clogged filter etc etc....





Your going to need the cash on this one!!
You will get LOTS of new parts
that you may not really need if they easter egg the repair vise troubleshoot the problem and find the real cause.Bill





Its really easy to get a meter and do the test that I layed out for you.. If you do the test and post the results, you can most likely get the thing repaired for 1/16 of what a shop will charge you.
Its your money.
Bill
Its really easy to get a meter and do the test that I layed out for you.. If you do the test and post the results, you can most likely get the thing repaired for 1/16 of what a shop will charge you.
Its your money.
Bill
areful when connecting chcker---fuel will squirt everywhere-place plenty of rags around site--Attach with engine OFF !!!! best if sat overnite before checking so the existing pressure bleeds off and it won't make such a mess
1 Has anyone TUNED or REFLASHED your PCM?
2. Do you see ANY messages or warnings on the DIC when it happens?
Some things that you need to check!!!!
Find the FUEL PUMP FUSE in the engine compartment fuse box. On top of each fuse are two small test points. Obtain a DC VOLT Meter and read both of those test points to chassie ground (The ignition Switch will nee to be in RUN to read the voltage)
You should see full battery voltage. Compare that reading with the reading that you get reading directly on the battery terminals. Should be the same.
If that reads good,, you need to monitor your fuel pressure on the fuel rail. If the pressure drops off below 60 PSI ay WOT,, you have a fuel supply issue. Pump, Power supply, pinched line, dirty clogged filter etc etc....
areful when connecting chcker---fuel will squirt everywhere-place plenty of rags around site--Attach with engine OFF !!!! best if sat overnite before checking so the existing pressure bleeds off and it won't make such a mess











