Upgrades I Regret
05-27-2011, 11:43 AM
#31
"Anybody knows how this works?"
It causes the DME ECM to set the idle valve at a wider opening to raise
the idle RPM to compensate for the addition load of the compressor,
thus maintaining the original idle RPM as when the compressor was 'off'.
Bottom line: A rather Mickey Mouse approach to solve a problem the
so-called 'performance' chip was to solve, right?
It causes the DME ECM to set the idle valve at a wider opening to raise
the idle RPM to compensate for the addition load of the compressor,
thus maintaining the original idle RPM as when the compressor was 'off'.
Bottom line: A rather Mickey Mouse approach to solve a problem the
so-called 'performance' chip was to solve, right?
05-27-2011, 12:03 PM
#32
Drifting
Thread Starter
05-27-2011, 01:40 PM
#34
Three Wheelin'
I'll have to mull the MWF option over. I'm still experimenting with the bouncing idle. I'll turn the ISV up a bit more. It seems that turning on the AC helps a lot. What actually gets adjusted when the A/C is turned on? It seems like the engine load increases (obviously) and something is changed to hold the idle rpms from falling. Anybody knows how this works?
From what I understand, the bouncing idle most likely is a vacuum leak. Mine does it a bit, occasionally, but not enough to justify pulling the motor and solving all leak possibilities. Obviously, I took the same approach you're taking, so I understand. I'm holding on to it for now, so if you change your mind, let me know. Otherwise, good luck with the idle. Hope it all works it way out....
05-27-2011, 02:36 PM
#35
Rennlist Member
50,000 miles on a ....
97 Carrera with ANDIAL semi-LWF. Never had a problem from day 1. I don't know how much heavier the semi-LWF is over the stock RS LWF.
I also replaced the clutch at that time...its still in there, amazing.
I don't regret one (1) upgrade:
Semi-LWF
PSS 9 bought used, rebuilt 1X
TRG sways, not the best, but 1/2 the price of the RS
Tarrett drop links
ERP toe link
18" wheels (MY 2002 996 wheels)
FD Motorsports Stage I mufflers
Fabspeed X pipes into 200 cell cats
Heigo cage
Sparco seats
RS Carpet kit
RS door panels
Momo quick release wheel
GT 2 front splitters and tail
Ruf secondary oil cooler
I also replaced the clutch at that time...its still in there, amazing.
I don't regret one (1) upgrade:
Semi-LWF
PSS 9 bought used, rebuilt 1X
TRG sways, not the best, but 1/2 the price of the RS
Tarrett drop links
ERP toe link
18" wheels (MY 2002 996 wheels)
FD Motorsports Stage I mufflers
Fabspeed X pipes into 200 cell cats
Heigo cage
Sparco seats
RS Carpet kit
RS door panels
Momo quick release wheel
GT 2 front splitters and tail
Ruf secondary oil cooler
05-28-2011, 09:34 AM
#36
Racer
When you turn the AC on there is an input to the ecu which bumps up the idle. The input may be causing internal timing and mixtures changes or an output signal to the ISV or both (i don,t know which pin recieves the input). You could probably look at a wiring diag and find it. A 12v connection goes to the compressor clutch and must also reach the ecu when the AC is turned on. If you want a little air past the throttle plate when the butterfly is closed you could drill a small hole (3/32 + -) in the plate. If it doesn,t work you can plug it with a dab of epoxy. I have done this on carburators to alter the relationship between the blade angle at idle to get the progression circuit to start early BUT have not attempted it on a 993.
05-28-2011, 10:41 AM
#37
"The input may be causing internal timing and mixtures changes or an output signal to the ISV or both"
1. internal timing - NO
2. mixtures changes - NO
3. output signal to the ISV - YES, The DME ECM changes the duty cycle
signal to the idle valve as was indicated in a previous post.
1. internal timing - NO
2. mixtures changes - NO
3. output signal to the ISV - YES, The DME ECM changes the duty cycle
signal to the idle valve as was indicated in a previous post.
07-09-2011, 07:03 PM
#39
Hate to read these stories,,, Hope you get to the issue Matt!
I decided to go with the Andial MWF, hopefully it will give better performance than the DMF (should be more reliable, at least,) and I won't have any stalling issues.
https://rennlist.com/forums/993-foru...l-on-95-a.html
They are $947 as of today, and Pete at Andial is very helpful.
http://www.andial.com/pc_trans.html
I have a Wong chip as well. Steve's advice to me was to try it as-is, and if I see stalling symptoms he will send a new chip with the anti-stall code.
I decided to go with the Andial MWF, hopefully it will give better performance than the DMF (should be more reliable, at least,) and I won't have any stalling issues.
https://rennlist.com/forums/993-foru...l-on-95-a.html
They are $947 as of today, and Pete at Andial is very helpful.
http://www.andial.com/pc_trans.html
I have a Wong chip as well. Steve's advice to me was to try it as-is, and if I see stalling symptoms he will send a new chip with the anti-stall code.
Car has done 500 miles in the last week, mixed hwy/city driving. I've tried to get it to stall, dropping the RPMs from way up and it always "catches" slightly above 1,000 RPM, gives a slight bounce and settles at idle.
It behaved this way on first start. I drove it a couple days prior to doing the ECU adaptation sequence, I noticed no difference after doing a few cycles.
07-09-2011, 11:03 PM
#40
Actually my recollection is that Steve Wong does guarantee that his chip will prevent stalling on a '95 with LWF. It works for me.
07-09-2011, 11:20 PM
#41
He also mentioned something about changing the idle setting at the throttle body as being a possible solution for '95/LWF woes... I don't think he has made such an adjustment himself, but he knew of someone that had.
