66 Chevelle LSA/4L90E Conversion
Teching In
Joined: Aug 2016
Posts: 44
Likes: 0
From: Phoenix, AZ
Thread Starter
TECH Fanatic
Joined: Jul 2008
Posts: 1,569
Likes: 173
Update......... After driving the car on many Road Tours and now having 34,000 miles on it....... I have to say adding the LSA to this car was the best thing that ever happened to the car........ I only had one minor glitch over the years and that was my fault...... The nut on the alternator Battery charging wire loosen up and I didn't catch it.......Took a real mechanic 2 minutes to find the issue..... LOL..... Averages 22.5 MPG on the highway with enough power to get the heartbeat going whenever your foot asks for it........ I don't think that for street driving any mod's are required to get the H.P. up as these engines have all the torque required for street driving.......
Ken
Ken
Thread Starter
TECH Fanatic
Joined: Jul 2008
Posts: 1,569
Likes: 173
Update....... Didn't drive the car much this year, been driving the Impala all over..... Took the Chevelle out last week for a local show..... the car ran perfect as usual... On the way home after getting off the highway I noticed the engine was running rough...... Humm!!!!..... I was 10 minutes from home so when I got the car in the garage (no check engine light) I plugged the scanner in and no codes....... Hummm!!!!!......Used the infared heat gun and shot all the Header pipes...... #3 cyl was showing no heat....... Humm !!!!....... Put a spare coil on and started it up .......Same thing......Pulled the spark plug and it looked O.K........ Checked for spark and everything good......Hummm!!!!!......Got Air....Got Spark..... Fuel????...put a Noid light on the plug on injector #3 and everything good....... Hummm !!!!...... The only thing that made any sense was that the injector went bad (36,000 miles)....... Ordered a new set and put them in and the car run's perfect again......... You never know...... LOL
The real question is why were you not getting a misfire code for that cylinder? That would have me concerned, I recently had a similar situation and after scanning I got a P0308 code telling me #8 cylinder was misfiring, I tried the easy stuff first as this motor has over 150k miles and I am the original owner and knew the plugs and wires had never been changed, I installed a new plug and spark plug wire and no change, swapped the coil with a known good one and that took care of the problem.
Thread Starter
TECH Fanatic
Joined: Jul 2008
Posts: 1,569
Likes: 173
The real question is why were you not getting a misfire code for that cylinder? That would have me concerned, I recently had a similar situation and after scanning I got a P0308 code telling me #8 cylinder was misfiring, I tried the easy stuff first as this motor has over 150k miles and I am the original owner and knew the plugs and wires had never been changed, I installed a new plug and spark plug wire and no change, swapped the coil with a known good one and that took care of the problem.
Don't know...... The cylinder was getting spark and as far as the computer knew the injector was firing also......There wasn't a dead miss in the engine, it just ran a little rough
TECH Senior Member
Joined: Jun 2016
Posts: 22,287
Likes: 3,615
From: Central Cal.
I agree with this. As far as the ECM knew, all was functioning, except it wasn't. As long as everything is working electrically it sees nothing wrong. So no code(s).
It can run rough and misfire and not kick a DTC for it. It has to exceed the misfire threshold before it will If the threshold is, it misses 1000 times in a certain time frame and it misses 999, You won't get a cylinder specific misfire but will probably get a P0300.
However you can watch real time misfires and see what cylinder(s)are misfiring.
Teching In
Joined: Oct 2013
Posts: 36
Likes: 8
I have a build thread started. I was just trying to make conversations. Sorry to all. Not trying to intrude.
