RE: New TB & PCM/WOT Shift Point Problems

From: Bernd D. Ratsch (bernd@texas.net)
Date: Sun May 20 2001 - 21:37:31 EDT


Shawn,

On the throttle "sticking" part, it could be one of two items:

(1) TPS interfering with the Flometrics TB (Bruce did change the shafts
to fix this though)
(2) Check the fuel rail and see if the throttle linkage it hitting it.
If it is, you'll have to "ding" the rail a little bit to clear the
linkage. (It's in the Flometrics instructions with the TB.)

- Bernd

-----Original Message-----
From: owner-dakota-truck@buffnet.net
[mailto:owner-dakota-truck@buffnet.net] On Behalf Of Shawn Bowen
Sent: Sunday, May 20, 2001 6:55 PM
To: dakota-truck@buffnet.net
Subject: DML: New TB & PCM/WOT Shift Point Problems

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



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