Wish i could find the info on what adaption actually does. I am fairly certain it is buried in the workshop manual. but trawling through , i can't find it. It was also posted on rennlist but i can't find the specific post.
Poor running
- Thread starter ian harvey
- Start date
this is close to the info , wish i could find the actual document.The final paragraph is the useful bit.
Code:
Idle Adaptation<br /> "What exactly is a 'system adaptation', and how is this different from a<br /> battery disconnect reset of the DME?"<br /> The 964 DME ECM has two adaptations:<br /> 1. Idle Adaptation -<br /> On the earlier 3.2 DME system the idle was set by an external jumper<br /> (caused open-loop idle) & then the idle screw was set to "center"<br /> the idle RPM. On the 964, the Hammer causes the DME to go open-loop<br /> and then causes the DME to "step" to the center for 880 RPMs. This<br /> results in the closed-loop idle being "centered" for full<br /> regulation.<br /> 2. CO adaptation -<br /> The 964 DME ECM goes thru a CO adaptation whereby it runs open-loop<br /> without the O2 sensor to "center" the CO setting to allow for small<br /> variable changes, e.g. air leaks, fuel pressure, so in the<br /> closed-loop mode the O2 system has optimal range (similar to TRA in<br /> OBDII).<br /> Both of the adaptation values are "lost" if the constant battery<br /> voltage (pin 18) is removed. #1 above requires use of the Hammer. #2<br /> occurs at initial running after battery voltage "loss".<br /> "What happens with the idle in the case of a battery disconnect and no<br /> hammer adaptation?"<br /> The closed-loop still maintains the target idle of 880 RPMs but it's not<br /> optimized for load changes, e.g. the A.C. compressor, the fans, the<br /> lights, and the adapted CO setting.Thanks for the latest posts, gents. I'm not as clued-up as Steve and Laurence but I can readily pick up useful info from both and appreciate their trouble.
I definitely won't/don't need to crimp the fuel pipe, very good to know so I will swap the filter anyway. Assuming this doesn't work - does a superior mobile auto electrician posses a Bosch Hammer suitable to this fault finding task. (for the record Ben from Rennspeed is due to go on holiday otherwise I would try and limp to his premises 20 miles away. My previous preferred specialist has just retired.
I don't wish to cause or prolong and argument but the information from Laurence is thought provoking and rings a bell as my car frequently has the battery disconnected and (prior to this specific issue) needs a little more patience than it used to before it settles down to a decent tick-over after a cold start.
I definitely won't/don't need to crimp the fuel pipe, very good to know so I will swap the filter anyway. Assuming this doesn't work - does a superior mobile auto electrician posses a Bosch Hammer suitable to this fault finding task. (for the record Ben from Rennspeed is due to go on holiday otherwise I would try and limp to his premises 20 miles away. My previous preferred specialist has just retired.
I don't wish to cause or prolong and argument but the information from Laurence is thought provoking and rings a bell as my car frequently has the battery disconnected and (prior to this specific issue) needs a little more patience than it used to before it settles down to a decent tick-over after a cold start.
Steve Brookes
Moderator
Ian, a mobile autoelectrician won't have a hammer. It's old technology and they're quite rare. The right OBD stuff and laptop setup can do some of the diagnostics but I believe it's not straight forward (Laurence will know more than me). David Bladon, 964 register secretary, has a hammer. Knowing David as I do I would not be surprised if he came to you with it to give you some help with the diagnostics and to do an adaption. Send him a message (username Dekker).
Talat
Member
My issue is still unknown. Wasn't the AFM, O2 sensor and a raft of other things that my Indy checked. They adjusted the mixture and they say this has improved it slightly - it still stalls but not as much. All the problems started after I fitted the new exhaust system so they think a remap is in order. Will probably take it to Unit 11 now for a second opinion. On the plus side, at least it now starts on the button [
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]Talat, sorry you've not managed to get to the bottom of your issues, good luck.
(Steve, in theory if Dekker or anyone else with a hammer plugged it in to my car, or Talat's, would the cause of the problems be revealed, simple as that?)
(Steve, in theory if Dekker or anyone else with a hammer plugged it in to my car, or Talat's, would the cause of the problems be revealed, simple as that?)
Thanks Melv,
I'll check the earths, swapped one a couple of years ago.
If I don't use throttle on start up, it won't run at all since the recent problem arose.
Ian
I'll check the earths, swapped one a couple of years ago.
If I don't use throttle on start up, it won't run at all since the recent problem arose.
Ian
Ian,Hammer is just another diagnostic tool. There is no magic in it and it helps rather than solves issues. i.e. it can give useful pointers, it's up to the tech to interpret what the tool is telling you. For EXAMPLE you might get a particular code P101 (mass air flow sensor) obviously this tells you there may be a problem with that sensor but it can also possibly be another issue related to the sensor that is causing the code. Hope that makes sense?
With idle issues and off idle issues and idle / off idle with LWF it's especially difficult to trace the fault and I would not be surprised if no codes come up or if they do they may not actually point to the problem. However they may give some useful leads.
I did read somewhere, again some while ago , that 964 motronic mapping is not ideal and that the map for the RS LWF can be significantly improved to virtually eliminate stalling. I never looked into this further. JasonAndreas on Rennlist states this in a post somewhere back in time. (rennlist search is your friend on this subject)
With idle issues and off idle issues and idle / off idle with LWF it's especially difficult to trace the fault and I would not be surprised if no codes come up or if they do they may not actually point to the problem. However they may give some useful leads.
I did read somewhere, again some while ago , that 964 motronic mapping is not ideal and that the map for the RS LWF can be significantly improved to virtually eliminate stalling. I never looked into this further. JasonAndreas on Rennlist states this in a post somewhere back in time. (rennlist search is your friend on this subject)
Laurence,
Well explained, I get it now. Thanks again, much appreciated.
Well explained, I get it now. Thanks again, much appreciated.
Laurence,
Well explained, I get it now. Thanks again, much appreciated.
Well explained, I get it now. Thanks again, much appreciated.
It's not just me that gets the double post thing then ! must be a glitch in the forum software ?
Glad it made some sense Ian.
Glad it made some sense Ian.
Steve Brookes
Moderator
Laurence Gibbs said:
I find that of recent times it takes longer to submit the post and guess some press submit again by mistake before the first submission gets accepted?
Melv, I'm sure he could but he's a long way fro my gaff. Know anyone decent with a car transporter!
Seriously , though, I expect it to have to somewhere soon on a trailer. Just picked up the fuel filter today so I'll fit that first in the remote chance that it unblocks things...
Seriously , though, I expect it to have to somewhere soon on a trailer. Just picked up the fuel filter today so I'll fit that first in the remote chance that it unblocks things...
Is there a good reason why I cannot undo the far union, got the correct flange spanner, half decent access and leverage but I cannot budge it!
Hi Ian
If you haven't changed the filter before it will be very tough to undo. Suggest some penetrating oil and then two wrenches and brute force!! I changed my filters annually and never had the problem after the first change.
However, I doubt your issue has anything to do with fuel or fuel filters. Most likely cause is an air leak. Check the whole inlet side of the engine. It's not a 5 minute job and some of the access is very fiddly/tight. If that doesn't work remove the idle speed control valve and clean out with carb cleaner. If that doesn't work replace it with a new one - they are not expensive. A new one often deals with the idling issue you are describing.
Good luck.
Damen
If you haven't changed the filter before it will be very tough to undo. Suggest some penetrating oil and then two wrenches and brute force!! I changed my filters annually and never had the problem after the first change.
However, I doubt your issue has anything to do with fuel or fuel filters. Most likely cause is an air leak. Check the whole inlet side of the engine. It's not a 5 minute job and some of the access is very fiddly/tight. If that doesn't work remove the idle speed control valve and clean out with carb cleaner. If that doesn't work replace it with a new one - they are not expensive. A new one often deals with the idling issue you are describing.
Good luck.
Damen
Returned from holiday today, picked up some penetrating oil on the way home. An hour after spraying in on to the filter it came apart quite easily. I installed the new filter and normal service has been restored, all for £20, some oil and a few new spanners!
I reckon the old one had been on for around 12 years and the fuel sloshing around was mucky. It's a worthwhile change. For the record I'm going to let Ben from Rennspeed fit me a new fuel pump, it's probably 24 years old and may be part of my problem.
Thanks to whoever it was that suggested this course of action.
I reckon the old one had been on for around 12 years and the fuel sloshing around was mucky. It's a worthwhile change. For the record I'm going to let Ben from Rennspeed fit me a new fuel pump, it's probably 24 years old and may be part of my problem.
Thanks to whoever it was that suggested this course of action.
Pleased you got it sorted
Thanks Laurence,
I'll take a hack saw to the old filter and see if there's any logic to the notion that a failed filter could effectively stop the car.
I'll take a hack saw to the old filter and see if there's any logic to the notion that a failed filter could effectively stop the car.
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