Trouble with low rpm kr high load
05-23-2005, 11:09 PM
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Trouble with low rpm kr high load Ive tuned out all kr and my ve table is nice and smooth with lt and stft's between +-5
I get kr whenever the converter locks in 4th with manifold pressure at 80+ kpa (under load) between 1200-1600 rpms after locked. Ive tried raising locking points even raising tcc voltage to get it to lock faster. I only get the knock immediately after it locks.
After the converter is locked in 4th at the same rpms and manifold kpa it doesnt knock?
Here's the kicker when running 110 octane under the same circumstances I wont get knock. So this leads me to believe its real knock and sometimes it will get to 4 degrees.
The timing is low enough at those points that I dont want to lower it any more and sacrifice my part throttle power.
I get kr whenever the converter locks in 4th with manifold pressure at 80+ kpa (under load) between 1200-1600 rpms after locked. Ive tried raising locking points even raising tcc voltage to get it to lock faster. I only get the knock immediately after it locks.
After the converter is locked in 4th at the same rpms and manifold kpa it doesnt knock?
Here's the kicker when running 110 octane under the same circumstances I wont get knock. So this leads me to believe its real knock and sometimes it will get to 4 degrees.
The timing is low enough at those points that I dont want to lower it any more and sacrifice my part throttle power.
05-24-2005, 09:53 AM
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Trucks have a PE enable delay / rate that doesn't need
to be there. You want your enrichment rate set to 1
(or at least increased to roll on the PE quicker). I believe
the value is fraction-per-time-tick, 1="all, now!" and 0.125
would roll it on in 0.1 sec (being as the fundamental
time-tick is 12.5mS). You might play also with the mode
delay RPM and set it below the trouble spot. But for a
sporty truck, as opposed to a drag-trailer-uphill truck,
a more car-like PE rate (1.000) is the ticket.
to be there. You want your enrichment rate set to 1
(or at least increased to roll on the PE quicker). I believe
the value is fraction-per-time-tick, 1="all, now!" and 0.125
would roll it on in 0.1 sec (being as the fundamental
time-tick is 12.5mS). You might play also with the mode
delay RPM and set it below the trouble spot. But for a
sporty truck, as opposed to a drag-trailer-uphill truck,
a more car-like PE rate (1.000) is the ticket.
05-24-2005, 11:48 AM
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Jimmy could you explain why his truck not being in PE mode is causing him low rpm, knock retard? This is assuming his PE delay is set above the rpm where the KR is experienced.
05-24-2005, 02:16 PM
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Below the delay RPM, the PCM will delay /
roll on the PE slowly. So in effect he's not
getting the enrichment he needs to stop
ping, for a while. And by then he's probably
buried under big knock retard.
roll on the PE slowly. So in effect he's not
getting the enrichment he needs to stop
ping, for a while. And by then he's probably
buried under big knock retard.
05-25-2005, 03:15 PM
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The truck is not in pe mode. Whenever in pe mode I have no kr and can run as much timing as I want got it set around 35 %tps
Last edited by 02sierraz71_5.3; 05-25-2005 at 04:08 PM.
05-25-2005, 04:13 PM
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raised burst kr delta cyl air up to .055 from .045 at 1400rpm and up now Im only getting 1-2 kr and its alot more rare but when I do get kr its still in the same spot.
How do I know when the delta values I have are correct?
How do I know when the delta values I have are correct?
