Limp Mode?
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Registered User
Joined: Oct 2006
Posts: 20
From: Mississippi
Limp Mode?
What is limp mode?
My car hits the rev limiter 1-2 and 2-3 after installing a 3600 stall converter, is this "Limp Mode"?
If so how do I fix it.
1996 camaro, hot cam, hooker headers, MSD 6000, CAI, TB bypass, MSD plug wires and coil, B&M shift kit, 3.73 gear, PCMforless tune.
My car hits the rev limiter 1-2 and 2-3 after installing a 3600 stall converter, is this "Limp Mode"?
If so how do I fix it.
1996 camaro, hot cam, hooker headers, MSD 6000, CAI, TB bypass, MSD plug wires and coil, B&M shift kit, 3.73 gear, PCMforless tune.
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Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
"limp mode" is the program in the PCM that runs the engine when most of the sensor inputs have been lost. Its just good enough to keep the car running to get it off the road and into a service facility. Doesn't sound like the problem you are having.
Is it possible you have an OBD-I conversion? They will have problems with high stall converters.
Is it possible you have an OBD-I conversion? They will have problems with high stall converters.
Registered User
Joined: Jul 2002
Posts: 1,367
From: Burlington, NJ
on obd1 cars you need to tune the higher stall converters...anything above about 2800, from what i gather from others experiencing the same thing. they tune for it and it's fine after that.
BTW, limp mode is your cold settings. when the 02 sensors arent warmed up yet and your engine has yet to reach optimunm temperature. this is when you start the car cold until the temp reaches about 160
BTW, limp mode is your cold settings. when the 02 sensors arent warmed up yet and your engine has yet to reach optimunm temperature. this is when you start the car cold until the temp reaches about 160
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Joined: Feb 2004
Posts: 1,154
From: VA
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Joined: Mar 2002
Posts: 2,058
From: near waco tx.
yeah me...
send me your bin file, and i will fix it. vincentbergeron@yahoo.com
if i can make a 4400 stall work good on a dailey driver... i can fix yours
Registered User
Joined: Jul 2002
Posts: 1,367
From: Burlington, NJ
i got my info from my teacher, who's a 30+ year veteran in vehicle maintenance. and he has 15+ years teaching. i talked to him about this last week. but if he's wrong i'll inform him. i'm sure he'll take it well since he just published another book about maintenance on newer cars...
is it possible that "limp home" on GM cars is totally different from any other manufacturer? or just that LTx car's limp home is totally different from every other engine management program? seriously, ... if it is i want to know so i dont sound like a retard to any non=gm fans out there. if not, what's the cold start program called?
is it possible that "limp home" on GM cars is totally different from any other manufacturer? or just that LTx car's limp home is totally different from every other engine management program? seriously, ... if it is i want to know so i dont sound like a retard to any non=gm fans out there. if not, what's the cold start program called?
Administrator
Joined: Nov 1998
Posts: 71,094
From: Hell was full so they sent me to NJ
Cold start is in "start-up" mode when the engine is being cranked, within a few seconds of the engine actually starting and stabilizing, it switches to "open loop".
For some accurate info on these cars, look at these references:
Corvette Fuel Injection 1982-2001, Charles O. Probst, GM Part # 12497977, ISBN 0-8376-0861-9
Limp home mode is covered in several places. For example - Chapter 2, Engine Control Fundamentals, para. 6.7, Fuel Backup/"Limp Home":
From page 103, continuing the description:
Few people ever experience "limp" mode.
Also review:
Chevrolet Fuel Injection, Ben Watson, ISBN 0-7603-0422-X
For some accurate info on these cars, look at these references:
Corvette Fuel Injection 1982-2001, Charles O. Probst, GM Part # 12497977, ISBN 0-8376-0861-9
Limp home mode is covered in several places. For example - Chapter 2, Engine Control Fundamentals, para. 6.7, Fuel Backup/"Limp Home":
When the computer itself is not operating normally, engine management changes to Fuel Backup, or "limp home" mode. This could be under any of the following circumstances:
-a computer voltage less than 9 volts.
-a cranking voltage less than 9 volts
-missing or non-functioning Programmable Read-Only Memory (PROM)
-if the computer fails to issue Computer Operation Pulses (COP)
When one of these situations occurs, the computer runs on something called the CAL-PAK chip, operating the engine only on inputs from a few sensors: Manifold Absolute Pressure, Throttle Position, Engine Coolant Temperature and RPM
-a computer voltage less than 9 volts.
-a cranking voltage less than 9 volts
-missing or non-functioning Programmable Read-Only Memory (PROM)
-if the computer fails to issue Computer Operation Pulses (COP)
When one of these situations occurs, the computer runs on something called the CAL-PAK chip, operating the engine only on inputs from a few sensors: Manifold Absolute Pressure, Throttle Position, Engine Coolant Temperature and RPM
The computer goes into backup ("limp home") mode if the system isn't functioning properly..... You'll get home or to the shop, but without full engine control.
Also review:
Chevrolet Fuel Injection, Ben Watson, ISBN 0-7603-0422-X
Registered User
Joined: Jul 2000
Posts: 993
From: Three Oaks MI
What is limp mode?
My car hits the rev limiter 1-2 and 2-3 after installing a 3600 stall converter, is this "Limp Mode"?
If so how do I fix it.
1996 camaro, hot cam, hooker headers, MSD 6000, CAI, TB bypass, MSD plug wires and coil, B&M shift kit, 3.73 gear, PCMforless tune.
My car hits the rev limiter 1-2 and 2-3 after installing a 3600 stall converter, is this "Limp Mode"?
If so how do I fix it.
1996 camaro, hot cam, hooker headers, MSD 6000, CAI, TB bypass, MSD plug wires and coil, B&M shift kit, 3.73 gear, PCMforless tune.
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Joined: Sep 2002
Posts: 2,193
From: High Ridge, MO
Registered User
Joined: Jul 2000
Posts: 993
From: Three Oaks MI