Engine Code 21 & 33
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Junior Member
Joined: Apr 2006
Posts: 21
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Engine Code 21 & 33
I need some help! I am having issues with my 91 Z28 with T.P.I. It started having problems here lately with stalling out, difficulties staying running and difficulties starting. As I drive it starts to die and I have to shift in neutral to rev the RPMs up to keep it running. I have read the codes and they are as follows:
21.
High voltage at throttle positon sensor
33.
High voltage (low vacuum) at mass air flow sensor (or MAP sensor)
I have replaced the TPS and the MAP sensor but to no avail. About two years ago I had to replace pretty much everything in the fuel system. Fuel Sending, relay, injectors, fuel filter, fuel pressure regulator. (Don’t know if it matters but I thought I would mention it)
The car seems to run really rich from the smell of the exhaust and it has always seem to have a low idle. There were times before my current problem where the car would even stall at stop signs on occasion. It has smelled rich even before the changes to the fuel system.
I have followed some of the discussions here on the forums, like checking vaccuum lines and checked the fuel pressure. They both seem fine.
Could this mean that there is something wrong with the computer? I am not sure, and do not want to buy a new one if it could be something else.
Any suggestions?
21.
High voltage at throttle positon sensor
33.
High voltage (low vacuum) at mass air flow sensor (or MAP sensor)
I have replaced the TPS and the MAP sensor but to no avail. About two years ago I had to replace pretty much everything in the fuel system. Fuel Sending, relay, injectors, fuel filter, fuel pressure regulator. (Don’t know if it matters but I thought I would mention it)
The car seems to run really rich from the smell of the exhaust and it has always seem to have a low idle. There were times before my current problem where the car would even stall at stop signs on occasion. It has smelled rich even before the changes to the fuel system.
I have followed some of the discussions here on the forums, like checking vaccuum lines and checked the fuel pressure. They both seem fine.
Could this mean that there is something wrong with the computer? I am not sure, and do not want to buy a new one if it could be something else.
Any suggestions?
Supreme Member
Joined: Jan 2006
Posts: 3,341
Likes: 10
From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Scan Plan
You’re going to need a scanner to quickly diagnose the problem.
Once you get one, disconnect the TPS.
Barring wiring problems, If the ECM good the voltage you will be seeing on the scanner will be LOW.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
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My Brakes Don’t Work AT ALL When The Car Is In The Air
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Once you get one, disconnect the TPS.
Barring wiring problems, If the ECM good the voltage you will be seeing on the scanner will be LOW.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing!
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
My Brakes Don’t Work AT ALL When The Car Is In The Air
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