Rockers installed, computer learning issue? (PROBLEM SOLVED)
#21
Senior Member
Posts like a Camaro
Thread Starter
It has reduced in severity, but still feels like its tapping the rev limiter at about 5700. I don't have an actual scanner, just an aeroforce interceptor gauge.
-Foghorn "You mentioned 14* KR in your first post, that can certainly make the car feel very flat and powerless. The KR you're getting is likely the result of the increased airflow seen by the MAF now you have higher ratio rockers. It'* unlikely your Long Term Fuel Trims (LTFT) are locking in close to zero when in Power Enrichment (PE) mode. The result is lean fuel mixtures, detonation and then Knock Retard (KR)."
So does that mean the computer needs more time at WOT to re-learn how much fuel is needed? I can do that. That was my initial impression, but then I thought it was springs.....now I don't know. Do the rockers increase the airflow enough that the computer would need a decent amount of time to relearn the fueling?
-Foghorn "You mentioned 14* KR in your first post, that can certainly make the car feel very flat and powerless. The KR you're getting is likely the result of the increased airflow seen by the MAF now you have higher ratio rockers. It'* unlikely your Long Term Fuel Trims (LTFT) are locking in close to zero when in Power Enrichment (PE) mode. The result is lean fuel mixtures, detonation and then Knock Retard (KR)."
So does that mean the computer needs more time at WOT to re-learn how much fuel is needed? I can do that. That was my initial impression, but then I thought it was springs.....now I don't know. Do the rockers increase the airflow enough that the computer would need a decent amount of time to relearn the fueling?
#22
Senior Member
Posts like a Corvette
Join Date: Jan 2004
Location: Montréal, QC
Posts: 1,374
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by chadow427
So does that mean the computer needs more time at WOT to re-learn how much fuel is needed?
How'* that scan coming along :?:
Cheers,
#23
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
I'm almost certain its valve float. I had the same situation when I first put my 1.9'* on and that was with 35k miles on the car. We thought for the longest time it was a rev limiter issue (PCM'* were just coming out back then) but put springs on the car and it went away. You can get KR from being to rich as well as to lean and if the valves are not closing all the way this can really mess up the 02s reading.
#24
Senior Member
Posts like a Corvette
Join Date: Jan 2004
Location: Montréal, QC
Posts: 1,374
Likes: 0
Received 0 Likes
on
0 Posts
After having done his rockers 3 times already and with other problems showing up, I wouldn't be in a rush to swap springs before knowing more about what'* going.
While you can have KR from overly rich mixtures, it'* unlikely in this case as he was not having this problem before installing the rockers, not to mention he'* more likely to be lean after having increased the airflow.
The rev limiter for a 2000 SSEi is set at 5950 RPM for the high limit.
While we can't rule out valve float, it'* speculation to say what'* going on without seeing a scan first. Still, with 14* of KR you had a maximum of 2.5* of timing advance at 5700 RPM...care to guess how gutless the car would feel with so little timing?
Let see a scan
Cheers,
While you can have KR from overly rich mixtures, it'* unlikely in this case as he was not having this problem before installing the rockers, not to mention he'* more likely to be lean after having increased the airflow.
The rev limiter for a 2000 SSEi is set at 5950 RPM for the high limit.
While we can't rule out valve float, it'* speculation to say what'* going on without seeing a scan first. Still, with 14* of KR you had a maximum of 2.5* of timing advance at 5700 RPM...care to guess how gutless the car would feel with so little timing?
Let see a scan
Cheers,
#25
Senior Member
Posts like a Camaro
Thread Starter
I can do a visual scan with the aeroforce, but I can't record with it. Should I scan for STFT or LTFT? I've got the two "screens" and can record for a little bit, but I don't know what to look for.
#26
Senior Member
True Car Nut
Join Date: Jul 2003
Location: Westerville, Ohio 2000 Black SSEi
Posts: 6,127
Likes: 0
Received 1 Like
on
1 Post
I would scan 02 MV and Timing.
If they dont drop immediately to 0 and then bounce (rev limiter) but they do bounce up and down when its happening its probably valve float.
If they dont drop immediately to 0 and then bounce (rev limiter) but they do bounce up and down when its happening its probably valve float.
#28
Senior Member
Posts like a Camaro
Thread Starter
Problem solved. It must have been valve float, because I put the springs on today and it revs freely all the way to redline. It also killed all my KR with the 3.4. Now to drop down to the 3.2 or even 3.0 (on race gas) .
Thread
Thread Starter
Forum
Replies
Last Post
xtremerevolution
Performance, Brainstorming & Tuning
7
06-04-2010 06:52 PM