Poor Acceleration from a stop / DDEC I II III IV / smoke control / Fix ??

[homermandy]

Forgot to mention that on my Pro-Link, there is an option which shows Smoke Control YES/NO(I think option 31). Anyways, it shows NO on the ProLink.  I would have thought it would be set to Yes. 

[RTS/Daytona]

homermandy

Thanks for the followup - hmmm don't understand your PRO-LINK "no boost" reading with the 100 ohm - when Bill did the testing his Pro-Link showed a few pounds boost ??

Glad the 100 ohm still works for you - received another report yesterday - 100 ohm worked great for a Blitz re-built RTS ddec II 6V92TA

Pete

I don't understand D/D "smoke Control" option - I'm confused - but we appear to have a good "work around" - the 100 Ohm resistor wired between the Turbo Sensor pin "C" and "B"

[homermandy]

Took another spin tonight. Had the prolink hooked up to monitor boost while driving.  Interesting, the boost registered on the prolink was half of the boost registered on my guage.  I can pull about 20psi at full boost.  However the prolink never got over about half.  Now someone else had a similar(maybe not similar) issue where the ECM read full boost then fell to zero. His problem was fuel starvation if I remember correctly. Anyways, it makes me intrigued.  I didn't measure boost without the resistor yet, but I would believe it would have no effect in the upper boost range. Anyone else seen this?  I doubt my guage is wrong......

[homermandy]

I suppose on the troubleshooting side, 1st I should make sure I have 1volt at pinB for zero boost.  If that does not register correct voltage, sensor may be broken. AND, it could be possible I have a small enough leak in the hose from the blower to the sensor causing the low voltage. But I would think if voltage measures around 1V at idle, sensor probably is ok. 

[RTS/Daytona]

homermandy

Hmmm - I think you need to remove the resistor and hookup the prolink and take it for another ride - just to eliminate any false readings due to the resistor

But I don't believe that the resistor has any effect at full boost

Pete RTS/Daytona

[homermandy]

Ok, so I got more ambitious. Without the resistor, lead c measures 5V, lead B measures 1V.  Prolink registers 0psi.
With the resistor, 5V at C, almost 2V at B, and still 0psi at Prolink. Won't be able to take for a spin until tomorrow evening.
Also put 5V directly to B and a fault registered on Prolink. hmmmmm

[RTS/Daytona]

pin B - operating range - approx .5v to 4.75 - voltages outside this range will cause a DDEC Fault

[homermandy]

Ok, so I think we may not understand how the DDEC program works. I had a potentiometer wired for about 50ohms between b and c pins. Checked voltage was about 3 volts or so. When yu turn on the ignition, it takes a while for the prolink to initialize. But i quickly scrolled down to boost PSI and it was dropping to zero(soonest I could get the display scrolled it was about 5psi). So I believe the prolink is getting the correct psi reading, but I believe it uses other parameters also. Not sure why it would not stay on what would be like 10psi? But it definately dropped to zero.  hmmmm.

[homermandy]

Here is the link to the similar boost behavior....

http://www.busnut.com/bbs/messages/233/10261.html

[Rich (Prevost)]

Neat stuff Pete.............Keep me posted.

Rich
800-468-5287