emissions/ecm??
02-15-2011, 07:27 PM
#1
Member
Thread Starter
Join Date: Aug 2010
Location: California
Posts: 120
Likes: 0
Received 0 Likes
on
0 Posts
Car: 91 camaro rs
Engine: v6 :/
Transmission: auto
emissions/ecm??
had this car for a few months. got it finally running smoother. there is a tick..in the motor..and possible head gasket problem..but after fixing the timing i havent seen anything out of the exhaust.. well the car is showing check engine light and i pulled 3 codes out
23- Manifold air temp sensor
35- idle speed control
42- electronic spark timing
they all have commen problems they could be. wiring, bad connections or open shorts..and defective ecm..the check light isnt always on. shows up after car running for a bit...is there a way to test the ecm? and how much do they go for? oor could it be something else..could just these 3 things be bad
23- Manifold air temp sensor
35- idle speed control
42- electronic spark timing
they all have commen problems they could be. wiring, bad connections or open shorts..and defective ecm..the check light isnt always on. shows up after car running for a bit...is there a way to test the ecm? and how much do they go for? oor could it be something else..could just these 3 things be bad
02-16-2011, 01:00 PM
#2
Supreme Member
Join Date: Sep 2002
Location: Cary, North Carolina
Posts: 9,192
Likes: 0
Received 16 Likes
on
16 Posts
Car: 1992 RS
Engine: Carbed 350
Transmission: 700R4
Axle/Gears: 3.42 posi
Re: emissions/ecm??
I'd start with the issues, and forget the ECM. Everyone and his brother replaces the ECM all the time, rarely is there an actual issue with the ECM.
Did you disconnect the EST wire when you changed timing? Did you reconnect it?
MAT is the little sensor in the air cleaner (I'm assuming this is a TBI car) - about $5 to replace - make sure its in the air cleaner and connected.
Idle speed control probably an issue with the Idle Air Control - there's a gazillion posts about cleaning, testing, and adjusting it here. Could also be a problem with the TPS - again many article here on testing.
Solving the EST issue might make the other two go away, so try there first. You have to set base timing with EST wire disconnected - disconnect before starting engine, set timing, kill motor, reconnect EST, restart motor. Then, disconnect the battery for 5 minutes, and reconnect. Then drive, get up to temp, go city stop/start, highway, and a few WOT - then recheck codes and go from there.
Did you disconnect the EST wire when you changed timing? Did you reconnect it?
MAT is the little sensor in the air cleaner (I'm assuming this is a TBI car) - about $5 to replace - make sure its in the air cleaner and connected.
Idle speed control probably an issue with the Idle Air Control - there's a gazillion posts about cleaning, testing, and adjusting it here. Could also be a problem with the TPS - again many article here on testing.
Solving the EST issue might make the other two go away, so try there first. You have to set base timing with EST wire disconnected - disconnect before starting engine, set timing, kill motor, reconnect EST, restart motor. Then, disconnect the battery for 5 minutes, and reconnect. Then drive, get up to temp, go city stop/start, highway, and a few WOT - then recheck codes and go from there.