Has anyone regreted changing to the LWF?
01-12-2009, 05:58 AM
#46
A bit off-topic, but I think we're just about due to get an update on your car, Chris 
As you can see from the above responses, people's experiences as to stalling differ. OBD is a US polution control system right? If so, I do not have it and still experienced very significant stalling issues on my 1996. I cannot say whether this was mainly attributable to the LWF and/or the 9M sport cams. The problem was much as described above - the system was just not fast enough to detect idle. After much anguish and having two different shops try and cure the stalling, I totally cured the issue by changing from Motronic to Motec engine management and no longer using the air mass sensor but a manifold sensor, and having brand new engine mapping. I undertook this at no small cost, not just to cure the idle issue but to get the most performance out of my modified engine and 100 cell cats. The stalling was maddening and this is what I ended up as pre Motec, but in the end it was all worth it:
01-12-2009, 11:35 AM
#47
I would suggest a "live remap" would cure the stalling issue (and give more BHP). They are reasonably popular here in the UK so would imagine they can be done in the US. Basically the parameters in the chip you currently have in the DME is re-programmed to suit your specific car and its engine. This is done on the dyno hence the "live" part of the remap. Will do what after market chips do but better as it's tailored to suit your car. The idle can also be adjusted and the cut off of the injectors is either eliminated or made more progressive so the car will not stall. The vram/resonance flap opening and closing can also be adjusted. Typically here it's £500 for such a service from the best in the business. I guess that's $700-750?
01-12-2009, 11:53 AM
#48
Rennlist Member
There's a procedure for checking vacuum in the factory manual. Essentially, you unplug the vacuum line on the fresh air flap and hook up a vacuum gauge. Start the car and rev it a bit to generate vacuum. When you shut the car off, the car should hold the vacuum generated. If it doesn't hold for at least several minutes, you have a leak.
I'll bet ya a number of our friends with stalling problems have a vacuum leak.....
I'll bet ya a number of our friends with stalling problems have a vacuum leak.....
Or perhaps a $20 boost gauge from Pep Boys will do the trick. Come to think of it, I have a cheapo boost gauge I can try out.
I am pretty sure that there is a signal from the climate control to the ECU to tell it that the A/C is turned on. This has the effect of increasing the idle speed to compensate for the A/C compressor load. Many people have said that it does not stall with the A/C turned on. This is why.
When I install a LWF, I plan to hot-wire my ECU so it thinks that the A/C is permanently on. Anyone care to try this first?
John
When I install a LWF, I plan to hot-wire my ECU so it thinks that the A/C is permanently on. Anyone care to try this first?
John
01-12-2009, 01:08 PM
#49
Three Wheelin'
I recently replaced the clutch on my 8/94 late build 95 and had the choice to replace - LWF or DMF... I ended up replacing with DMF. I justified this by telling myself that if I needed someone else to drive the car or was going to sell it to someone who isnt well versed in LWFs, the DMF car is easier to drive. I would hate to lose a prospective buyer trying to explain that stalling is to be expected. With that said, I dont plan on selling but then again, these clutches last a looong time. Who know whats going to happen in the future!
01-12-2009, 01:18 PM
#50
Nordschleife Master
When I purchased Rufus just after the Ruf Turbo R conversion, the previous owner had tried the LWF. He found that the engine would die when coasting down an offramp. He had a new DMF installed. I still have all of the LWF, PP, clutch parts in case I ever wear out the existing clutch.
01-12-2009, 01:32 PM
#51
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I have a LWF in my '91 C2. I don't have any problems with stalling apart from occasionally when I have the air con on. Before having it re-gassed, it was fine. So, if you don't have aircon, or one that isn't gassed, you might not have any problems with OBD1.
01-12-2009, 01:37 PM
#52
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FWIW.. and perhaps to add a new information to this thread..:
- Verify all vacuum lines are secured.
- Set idle rpm to 960 rpm. These are the exact figures from the RS Tech manual.
Good luck
- Verify all vacuum lines are secured.
- Set idle rpm to 960 rpm. These are the exact figures from the RS Tech manual.
Good luck
01-12-2009, 03:09 PM
#54
Rennlist Member
I have a 95 with a LWF with no regrets. As Chris mentioned you need to change your clutching syle as well as not clutching in at low revs while coasting to a stop without a throttle blip. My first few weeks with it I stalled maybe 2-3 times. Now if I stall it it's just because I'm not paying attention or just drove my other cars that don't have a LWF and get "used" to their behavior.
01-12-2009, 04:15 PM
#56
Rennlist Member
I have a 94-build 95 and really enjoy the LWF with the RS clutch...quicker rev's and acceleration. I did have the annoying stalling issues, especially under high electrical loads (head lights, fog lamps, heater, etc). However, I recently adjusted the ISV to a higher rpm and that seems to help the ECU "catch" the rpm's on the way down. I wouldn't go back to a DMF...I like the LWF that much.
I learned to do much more heal/toeing to prevent the stall prior to the ISV fix (a good skill), but since I'm now contemplating selling the car (for a 997), I needed to make sure the new buyer didn't have the stalling issue.
I learned to do much more heal/toeing to prevent the stall prior to the ISV fix (a good skill), but since I'm now contemplating selling the car (for a 997), I needed to make sure the new buyer didn't have the stalling issue.
01-12-2009, 04:21 PM
#57
Rennlist Member
I have a 94-build 95 and really enjoy the LWF with the RS clutch...quicker rev's and acceleration. I did have the annoying stalling issues, especially under high electrical loads (head lights, fog lamps, heater, etc). However, I recently adjusted the ISV to a higher rpm and that seems to help the ECU "catch" the rpm's on the way down. I wouldn't go back to a DMF...I like the LWF that much.
I learned to do much more heal/toeing to prevent the stall prior to the ISV fix (a good skill), but since I'm now contemplating selling the car (for a 997), I needed to make sure the new buyer didn't have the stalling issue.
I learned to do much more heal/toeing to prevent the stall prior to the ISV fix (a good skill), but since I'm now contemplating selling the car (for a 997), I needed to make sure the new buyer didn't have the stalling issue.
01-12-2009, 04:51 PM
#59
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I have a 97 and have had zero stalling issues. I will say that it took me a while to get used to driving with a lwf though. Smooth starts, uphill starts. These are things that gave me trouble in the beginning but are fine now.
Overall a good mod, great given the fact that the cost is the same (if you are changing your clutch anyway). I don't mind the noise at all and actually like it.
Overall a good mod, great given the fact that the cost is the same (if you are changing your clutch anyway). I don't mind the noise at all and actually like it.
01-12-2009, 04:56 PM
#60
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Don't get a 997. Seriously. I had a 07 GT3. While incredibly capable and great fun to drive it is so capable that at sane speeds around town and on the highway it is dull to drive compared to a 993. I found myself grabbing the keys to the 993 far more often than the GT3 after the novelty of it wore off.