strange code
Thread Starter
Heel & Toe
Joined: Jul 2017
Posts: 22
Likes: 0
From: silver creek,ny
strange code
Hello, I am new to this site and we have an 88 corvette that we purchased about a month ago. It has only 28,000 miles on it so body and drive seem to be in very good condition.
Now my question, It popped a #33 code for the mass air flow sensor, we changed coolant sensor and also 2 relays as GM said the old style could be an issue. Car runs fine and all of a sudden pops code again. While scanning system with a snap on scan tool we noticed the TPS value was low. should be .52 at idle closed and go to 4.0 at WOT. Scan tool shows TPS only goes to 1.28 volts at WOT. We are thinking that this might be confusing mass air flow sensor and popping code. Are we heading in the right direction? Don't want to parts chase!! but can use some ideas. Shows no other codes and when #33 is clear car runs fine.
Thanks
Now my question, It popped a #33 code for the mass air flow sensor, we changed coolant sensor and also 2 relays as GM said the old style could be an issue. Car runs fine and all of a sudden pops code again. While scanning system with a snap on scan tool we noticed the TPS value was low. should be .52 at idle closed and go to 4.0 at WOT. Scan tool shows TPS only goes to 1.28 volts at WOT. We are thinking that this might be confusing mass air flow sensor and popping code. Are we heading in the right direction? Don't want to parts chase!! but can use some ideas. Shows no other codes and when #33 is clear car runs fine.
Thanks
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
You can get an error code 33 if there is a bad connection between the MAF and the ECM. That could be a corroded connector pin or a broken wire.
If the MAF signal is not getting to the ECM, it will use the TPS signal to guess what the air flow rate is. Try unplugging the MAF and see how it runs.
If the MAF signal is not getting to the ECM, it will use the TPS signal to guess what the air flow rate is. Try unplugging the MAF and see how it runs.
Thread Starter
Heel & Toe
Joined: Jul 2017
Posts: 22
Likes: 0
From: silver creek,ny
Hello, at idle either running or not it is .52 which is correct but it will not go over 1.28v at WOT. and yes, it is receiving 5 volts we checked with snap on scan tool and also a volt meter.
The car runs good, the throttle shows no sign of problems, you would think the low voltage would not make it accelerate but not the case, Thanks for your help
Melting Slicks
Joined: Jan 2014
Posts: 2,478
Likes: 254
From: Downers Grove Illinois
Hello, at idle either running or not it is .52 which is correct but it will not go over 1.28v at WOT. and yes, it is receiving 5 volts we checked with snap on scan tool and also a volt meter.
The car runs good, the throttle shows no sign of problems, you would think the low voltage would not make it accelerate but not the case, Thanks for your help
The car runs good, the throttle shows no sign of problems, you would think the low voltage would not make it accelerate but not the case, Thanks for your help
Safety Car
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Hello, at idle either running or not it is .52 which is correct but it will not go over 1.28v at WOT. and yes, it is receiving 5 volts we checked with snap on scan tool and also a volt meter.
The car runs good, the throttle shows no sign of problems, you would think the low voltage would not make it accelerate but not the case, Thanks for your help
The car runs good, the throttle shows no sign of problems, you would think the low voltage would not make it accelerate but not the case, Thanks for your help
Check your TPS first.
Zen Vet Master Level VII
Joined: Mar 2016
Posts: 5,213
Likes: 1,173
From: Southlake, TX
