Thanks, so when your running your SC do you still have the issue?
I appreciate it,
Shawn
-----Original Message-----
From: owner-dakota-truck@BUFFNET.NET
[mailto:owner-dakota-truck@BUFFNET.NET]On Behalf Of Bob Tom
Sent: Sunday, May 20, 2001 10:42 PM
To: dakota-truck@buffnet.net
Subject: Re: DML: New TB & PCM/WOT Shift Point Problems
At 07:55 PM 5/20/01 -0400, you wrote:
>I just put on both a Flow Metrics 50mm TB and had my PCM reflashed by
Leach.
>Well, I know they bumped the Rev limiter made other changes to the PCM,
>unfortunately I need to call them to give me the exact numbers. My problem
>is this, since replacing the TB the throttle seems sticky at times. The
>shifting at half throttle kicks ass but at WOT it almost feels like I'm
>bumping the Rev limiter before shifting, this is right around 5k RPM's.
I'm
>hesitant to really get on it because I had the PCM setup for a PowerDyne
>Supercharger, but it isn't here yet. At WOT it sort of feels like the fuel
>is cutting out at around 5K, if I let up a little it will shift and then
>pull HARD until around 5K again. I believe the Rev limiter was set to 6500
>RPM's so this concerns me.
> I made several changes this weekend. Put the new TB on, replaced
> the Fan
>Clutch with a Black Magic electric, and dropped the new PCM in. I drove
>about 100 miles at varying speeds on both the highway and in the city and
>then in traffic (checking the Fan out in Atlanta traffic;-)). The truck
>pulls a LOT harder when I get on the gas but at WOT the shifting scares me
>so I back off.
> I know the transmition has linkage on the TB and was wondering if
> that
>could be the source of the sticking issues. I am also wondering if maybe
>I'm getting lean at WOT and starving of fuel, the reason I'm curious is
that
>the PCM was setup for the PowerDyne with a new fuel pump. On two occasions
>the MIL light flashed when this occurred at WOT, only for a split second.
>Currently, while waiting on the Supercharger I'm still using the stock
>airbox and filter, that's why I'm wondering about whether I'm running lean
>and that's causing the engine to cut out.
>
>Currently the truck is setup as follows:
>5.2L 318
>180 T-Stat
>Black Magic Electric Fan (no fan clutch)
>Flow Metrics 50mm Throttle Body
>Gibson Dual Cat Back
>Stock Airbox (until either the SC or the K&N FIPK I ordered shows up)
>Leach Custom PCM setup for the SC
>93 Octane Fuel
>
>Any help or advice would be appreciated!
>
>Shawn
>98 5.2L 4x4 CC
Shawn
I tested a MP PCM which was custom programmed for blower and juice
application on my N/A Dak. With such a programmed PCM, timing will
be retarded quite a bit at WOT (to prevent detonation) and will also have
a very rich AFR. On the PCM that I tested, the timing at WOT was backed
off to 17 degrees compared to the 28-31 degrees on a N/A calibrated PCM
for the 5.2L.
I'm pretty sure what you are experiencing (without the SC on) is the
timing retard and the extremely rich AFR calibrations.
I also have the '97 MP PCM (CA version; no Fed version) and get a
similar experience at WOT at the shift points. At WOT, this PCM
retards timing to 7 degrees from mid-20 degrees at the shift points.
HTH
Bob Tom Burlington, Ont., Canada
'97 Dakota Sport, 4x2, CC, Flame red, 5.2L, auto., 3.92SG
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