I've had a scanner hooked up to my Dak quite a few time and your timing does
seem pretty low. It's been a while but if I remember correctly at idle I had
about 17 degs, on the high end it went to around 35 degs. I have 4 degrees
pulled out on a custom flash so on a stock PCM it would show more. Your TPS
at 11 deg is the same as mine at idle. The lower idle speed may have to do
with the 5 speed, on older cars you set the idle higher on autos than 5
speeds, not sure about new vehicles whether the computer take this into
account or not. Fluctuating idle or surging at highway speed may be the TPS
sensor. The map sensor is taking readings from the throttle body not the
manifold so that may account for the difference in vacuum readings. I ended
up taking my MAP sensor and hooking directly to the manifold. I was seeing
fluctuating map voltages with the ported TB under boost. Seems to work
better.. hope this helps.
Mike Williams
00 Blk R/T RC - ProCharged
http://mid-mich-mopars.org/daks.htm
----- Original Message -----
From: "Doug Myers" <dougmyers@starpower.net>
To: "Dakota Mailing List" <dakota-truck@buffnet.net>
Sent: Sunday, July 16, 2000 1:37 AM
Subject: DML: slow timing?
> Hey guys,
>
> I recently bought an Auto Xray scanner and have been playing with it
on
> my Dak. I've found some interesting things about the timing. At idle, the
> timing varies between 0 - 4 degrees. At full throttle, total timing seems
to
> somewhere around 26-28 degrees, but it isn't all in until almost 5,000rpm.
> Between 2500-4000 timing was at around 19 degrees. Cruising at 55mph in
5th
> gear gives me 40 degrees timing. It seems to me that I've got an EXTREMELY
> slow advance curve, though the electrical equivalent to a vacuum advance
> appears to be working. Any thoughts on what might be causing this?
Shouldn't
> I be getting around 10-12 degrees at idle? I have the stock PCM. Also, my
> idle isn't really steady. It varies about 75 or so rpm, though it seems to
> idle around 600rpm or so. Throttle position at idle is 11%. Another thing
is
> that my MAP sensor is only showing 12 inches of vacuum while the engine is
> actually producing 16-17.
>
> Doug Myers
>
> '99 Dakota RC/SB 318/5-speed/3.92SG
> ------------------------------------------
> Accel Supercoil, MP 7.5mm Plug Wires, Brass Cap & Rotor, Turbo City Dual
> Inlet Air Tube, 180 Degree Thermostat, MP Cam/Lifters/Valve
> Springs/Retainers, MP Double Roller Timing Chain, MP Headers, MP Cat-Back,
> BFG 275/60R15's, Continental Hard Tonneau
>
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