Problems going past 4000 RPM
Thread Starter
3rd Gear
Joined: Sep 2006
Posts: 3
Likes: 0
Problems going past 4000 RPM
Hi guys,
I have an '02 Vette n I've noticed that ne time I go past 4000 rpm its like the computer cuts my engine off and I have to shift to a higher gear so that the rpm can be lowered. I called a Chevy dealer n the service center guy told me that the C5 is designed with the red limiter (?) and its a feature of the car to protect it . I find that hard to believe cuz I'm no where close to redlining!!! I lost to a C4 the other day cuz of this problem!
Does anybody have any idea about what could be going on??
I have an '02 Vette n I've noticed that ne time I go past 4000 rpm its like the computer cuts my engine off and I have to shift to a higher gear so that the rpm can be lowered. I called a Chevy dealer n the service center guy told me that the C5 is designed with the red limiter (?) and its a feature of the car to protect it . I find that hard to believe cuz I'm no where close to redlining!!! I lost to a C4 the other day cuz of this problem!
Does anybody have any idea about what could be going on??
Instructor
Joined: Jun 2006
Posts: 211
Likes: 2
From: Glendale CA
Its acctually commonly called a "Rev" limiter, which cuts either fuel or spark once past redline, to keep you from blowing your motor.
At 4000 your nowhere near redline so he was wrong, thats not whats happening. Something else is going on. Sorry not more help but at least you know its not the red I mean Rev limiter..
At 4000 your nowhere near redline so he was wrong, thats not whats happening. Something else is going on. Sorry not more help but at least you know its not the red I mean Rev limiter..
Last edited by TroutFisher; Sep 12, 2006 at 11:42 PM.
Thread Starter
3rd Gear
Joined: Sep 2006
Posts: 3
Likes: 0
Not sure if it has the valet switch on it, how can I find that out?
When I go past 4000 rpm, its almost as if the power is cut off and the rpm decreases, so I have to upshift.. in other words the car wont accelerate past that rpm unless I shift into a higher gear... does that clarify?
When I go past 4000 rpm, its almost as if the power is cut off and the rpm decreases, so I have to upshift.. in other words the car wont accelerate past that rpm unless I shift into a higher gear... does that clarify?
Pro
Joined: Jan 2004
Posts: 675
Likes: 0
From: FT Bragg North Carolina
do you know if its always done this or did it just start doing it?
I would start by checking the codes and posting up if you have any. Here is how to do it:https://www.corvetteforum.com/techti...D=26&TopicID=1
If this doesnt turn up anything odd You need to find someone near you with software that can check to see what your Rev limiters set at such as efi-live, HP tuners ect.......the dealership......can also do this but can be a pain to deal with...
I would start by checking the codes and posting up if you have any. Here is how to do it:https://www.corvetteforum.com/techti...D=26&TopicID=1
If this doesnt turn up anything odd You need to find someone near you with software that can check to see what your Rev limiters set at such as efi-live, HP tuners ect.......the dealership......can also do this but can be a pain to deal with...
Thread Starter
3rd Gear
Joined: Sep 2006
Posts: 3
Likes: 0
Ok so I got the codes....
10PCM - P0172H Fuel Trim System Rich Bank 1
P0175H Fuel Trim System Rich Bank 2
28TCS - C1295 Brake Lamp Switch Circuit Open
60IPC- B0521H Tachometer Signal Circuit Malfunction
U1160H Loss of Communications with LDCM
Aslo got a 99HVAC code, 5codes for A0LDCM and 3 codes for A1RDCM, but I didn't think those would be related to the problems I'm having.... does this help any??
10PCM - P0172H Fuel Trim System Rich Bank 1
P0175H Fuel Trim System Rich Bank 2
28TCS - C1295 Brake Lamp Switch Circuit Open
60IPC- B0521H Tachometer Signal Circuit Malfunction
U1160H Loss of Communications with LDCM
Aslo got a 99HVAC code, 5codes for A0LDCM and 3 codes for A1RDCM, but I didn't think those would be related to the problems I'm having.... does this help any??
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
The rev limitation is likely a symptom of another problem. The rich bank 1 and 2 means there is too much fuel and the O2 sensors are trying to compensate by pulling fuel out. It can only pull so much, and if the fuel trims drop below a certain percent, the codes will set.
Start with the simple things. Check the air filter first and make sure it is clean. Its not a K&N, is it? Then clean the MAF with electronics cleaning spray, non-residue type. Look at all the vacuum lines for any cuts or tears. Check the EVAP line especially, and also pull it off and look for signs of fuel, which could mean a saturated EVAP canister.
Has anyone done any tuning on this car that you know of?
PS: Stock rev limiter is over 6,000 RPM so you are no where near it. Also, there is a knock issue on the 02 stock tune (right around 4,200) so it may be a case of a lot of the timing getting pulled as well. I have seen three 02's with a dip in the dyno curve, including mine, right at 4,200. Here is my stock dyno and then after I installed my QTP headers. Notice the big dip in the stock curve, all the 02's I have seen have this dip. If you have other issues, you may be having trouble getting past it. But first, you need to figure out the rich codes.
Start with the simple things. Check the air filter first and make sure it is clean. Its not a K&N, is it? Then clean the MAF with electronics cleaning spray, non-residue type. Look at all the vacuum lines for any cuts or tears. Check the EVAP line especially, and also pull it off and look for signs of fuel, which could mean a saturated EVAP canister.
Has anyone done any tuning on this car that you know of?
PS: Stock rev limiter is over 6,000 RPM so you are no where near it. Also, there is a knock issue on the 02 stock tune (right around 4,200) so it may be a case of a lot of the timing getting pulled as well. I have seen three 02's with a dip in the dyno curve, including mine, right at 4,200. Here is my stock dyno and then after I installed my QTP headers. Notice the big dip in the stock curve, all the 02's I have seen have this dip. If you have other issues, you may be having trouble getting past it. But first, you need to figure out the rich codes.
Last edited by vettenuts; Sep 13, 2006 at 09:15 PM.
