LT1 Code 33
03-17-2008, 09:15 AM
#1
Race Director
Thread Starter
Member Since: Mar 2006
Location: Sherwood, Arkansas
Posts: 11,628
Likes: 0
Received 1 Like
on
1 Post
LT1 Code 33
If your 1992 LT1 started running really rough, missing badly especially at low RPM and you limped it home and pulled a code 33 "MAP Sensor". Would you order a new MAP sensor and try that first? I know what the FSM says but I do not have the means to test it the way the charts are laid out.
03-17-2008, 07:20 PM
#3
Racer
Member Since: Sep 2007
Location: Bartonville Illinois
Posts: 393
Likes: 0
Received 0 Likes
on
0 Posts
I have a 93 and since the sensor has only two screws and is cheaper than an appointment at a repair shop it would be less trouble and probably quicker. I looked around here once for one and nobody had any in stock, Seems like they were about $80-90
The diagnostics though could be pointing you to a vacuum leak rather than a bad sensor. You might want to look around for any cracks in some of the hoses. I have only owned mine for two years and I am sure a couple of the hoses left on it are 15 years old. I have been replacing them.
The diagnostics though could be pointing you to a vacuum leak rather than a bad sensor. You might want to look around for any cracks in some of the hoses. I have only owned mine for two years and I am sure a couple of the hoses left on it are 15 years old. I have been replacing them.
03-17-2008, 07:47 PM
#4
Race Director
Thread Starter
Member Since: Mar 2006
Location: Sherwood, Arkansas
Posts: 11,628
Likes: 0
Received 1 Like
on
1 Post
I have a 93 and since the sensor has only two screws and is cheaper than an appointment at a repair shop it would be less trouble and probably quicker. I looked around here once for one and nobody had any in stock, Seems like they were about $80-90
The diagnostics though could be pointing you to a vacuum leak rather than a bad sensor. You might want to look around for any cracks in some of the hoses. I have only owned mine for two years and I am sure a couple of the hoses left on it are 15 years old. I have been replacing them.
The diagnostics though could be pointing you to a vacuum leak rather than a bad sensor. You might want to look around for any cracks in some of the hoses. I have only owned mine for two years and I am sure a couple of the hoses left on it are 15 years old. I have been replacing them.
03-18-2008, 12:34 AM
#6
Le Mans Master
Member Since: Feb 1999
Location: Hawaii
Posts: 8,522
Likes: 0
Received 3 Likes
on
3 Posts
St. Jude Donor '03 & '05
I would have taken one off of another GM vehicle, first, to see if it really was bad. Just a quick troubleshooting fix, when money is tight. Most GM MAPS are the same.
03-21-2008, 10:26 AM
#7
Race Director
Thread Starter
Member Since: Mar 2006
Location: Sherwood, Arkansas
Posts: 11,628
Likes: 0
Received 1 Like
on
1 Post
Got these codes from Module 4: H33 (Map Sensor), H34 (Map Sensor), & H65 O2 sensor (right). Does this sound like it could be an O2 sensor problem?
03-21-2008, 02:35 PM
#8
Le Mans Master
Member Since: Feb 1999
Location: Hawaii
Posts: 8,522
Likes: 0
Received 3 Likes
on
3 Posts
St. Jude Donor '03 & '05
If yo have the code, it is telling the ecm that it is not getting back the correct voltage/signal. So, the Map is bad, or the wiring and/or plug is loose. MAPS go. Take it out and look at the gasket, a little orange one, and see if it is ripped. Otherwise, take one off another car or go buy one. They are cheap, even junkyards have them on many many GMs.
03-21-2008, 03:20 PM
#9
Drifting
Actually, when I think about it, it wasn't the EGR sticking, the valve that controls it was leaking and directing vacuum to the EGR when it wasn't supposed to causing the EGR to be open when it wasn't supposed to be. This caused manifold pressure readings that were out of range and hence the code.
03-21-2008, 04:00 PM
#10
Race Director
Thread Starter
Member Since: Mar 2006
Location: Sherwood, Arkansas
Posts: 11,628
Likes: 0
Received 1 Like
on
1 Post
If yo have the code, it is telling the ecm that it is not getting back the correct voltage/signal. So, the Map is bad, or the wiring and/or plug is loose. MAPS go. Take it out and look at the gasket, a little orange one, and see if it is ripped. Otherwise, take one off another car or go buy one. They are cheap, even junkyards have them on many many GMs.
