John,
Take the TB off of the truck and, with the blades closed, see how much
light is coming through the blade edges (blades closed). If there is a
very noticeable amount, you can first try to readjust the throttle blade
stop screw (may have to remove the cap - linkage side of TB on top
corner)...if that doesn't work, bore size was made too big for factory
blades (unless he changed the blades to match the new bore size). If
there is too much air going past the blades, idle will be affected as
well as normal cruising - vacuum leak - too lean and IAC closes
completely in an attempt to compensate.
Definitely check the TPS and IAC first though...they can cause these
problems as well.
- Bernd
-----Original Message-----
From: owner-dakota-truck@bent.twistedbits.net
[mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of John Bell
Sent: Tuesday, June 24, 2003 9:38 PM
To: dakota-truck-moderator@bent.twistedbits.net
Subject: DML: TB Mod Problems: DTC P0121 and DTC P0133 (long)
OK folks, I could really use your help on this one...
I got my truck back from the machinist. He was able to tap out the
offending broken S-Bolt stub (see the "T*man's Curse LIVES" thread for
the gory details). Unfortunately, the guy who did the work is not, I
repeat, -not- a mechanic. It's fairly obvious that he wasn't able to
bolt everything together properly once he had finished up his work.
While he had the TB off, I told him to go ahead and mill the TB
according to the various instructions and pictures provided on the DML
web site. According to the Mark I Eyeball, the milling was done to my
satisfaction.
Here is what I did when I picked up the truck:
- Pulled the negative battery cable and reset the PCM (held the key in
START for about 20 seconds, which cleared the Check Engine light I got
when I first tried to start it
up)
- Once I did that, the Check Engine light cleared, but idle would bounce
around between 1400-1600 rpm (as opposed to the stock 650 rpm I normally
had)
- Once I started driving, the Check Engine light would come on again
after going a few miles.
Symptoms:
- Idle between 1400-1600 rpm
- Failed to shift into O/D while driving
- What felt like a "fuel cut off" at 4500 rpm when revving the engine in
park
I have two methods of pulling DTCs. The first is with my Hypertech Power
Programmer III. When I used it, it returned a DTC code of P0121 (TPS
signal does not correlate to MAP signal).
The second method is with my CarChip. In the trip log / vehicle trouble
log summary, it showed that a DTC of P0133 is being consistently
generated on the test trips I took while debugging. DTC P0133 is "O2
sensor 1/1 response slower than minimum required switching frequency".
It is my understanding that DTC P0121 will -not- activate the Check
Engine light, but that DTC P0133
-will- activate it. Please correct me if I am mistaken.
If I was going to take a guess, I would guess that the guy who did the
machining work did not put the TPS back on the TB correctly when he
reinstalled it. I found out that the IAS is the piece that is in charge
of idle and O/D shifting according to the list archives, however.
Needless to say, there are multiple places where things could be
failing:
- TPS misinstall/malfunction
- IAS " "
- Throttle linkage " "
- Damaged MAP sensor
- Possible TB gasket and/or vaccuum leak (he -did- use a fresh TB
gasket, which I provided)
The TPS was modded in the past (bore out the brass inserts mod) - this
was noticed by the machinist when he took apart the TB setup in order to
get it to the bench. I had Bernd do this back when I took my truck to
Speedtweaks for the "power tuneup" (which worked beautifully).
I hope I've given enough info for the Big Dogs on the list to make
suggestions. Any help in getting this fixed is *greatly* appreciated!
Any tips on some *** good *** mechanics in the Austin TX area who
explicitly work on Dodges would also be greatly appreciated (man, I
-really- miss Bernd and Speedtweaks, that would be ideal). Barring that,
any tips on dealers in the Austin TX area who can be trusted to fix this
without recommending a complete overhaul to stock would also be nice.
Thanks much,
-- John Bell '00 QC SLT+ 4x4 5.9 46RE NV242 *** Check Engine Light Mod ***
This archive was generated by hypermail 2b29 : Fri Feb 06 2004 - 11:46:30 EST