[MLB]

Thanks flash

(And now back to our regularly scheduled conversation, already in progress. ;0)

Partial Post: Please Login or Register to read the full post.

[ds968]

The ICV is out , and it looks super clean. Nothing gummy or dirty in there , at least not that's visible . So it could be something mechanical inside that's not functioning properly . Now that its removal and reinstall is not nearly as complex as originally thought , I'll probably order a used one from the guy that rebuilt my engine ( he has a couple of 968 ICVs available ) that's in good working order and see if and how long that runs without problems. It's not that I can't afford $ 450 for a new one from Porsche, but I have a problem with the principle of dealers' outrageous markups on parts in general, considering I can usually find the OE elsewhere for often less than 1/3 of the dealer price . Unfortunately no one carries the jCV for some reason . Not Paragon, not Pelican, not Rennbay, etc. Found some Asian ICV which supposedly is an exact replica of the OE of the 968 for just $ 30 , but I'm Very skeptical about that one .. It may fall apart taking it out of the box .

Partial Post: Please Login or Register to read the full post.

[Waylander]

Try Going to your local Bosch Injection Specialist shop, and use the bosch part number off the side to order,

 

there are quite a few genuine bosch ones that will fit

Partial Post: Please Login or Register to read the full post.

[ds968]

The " local " Bosch Injection Specialist shop ?! I'll definitely run a search for that , but I've never heard about anything of the sort in the U.S, There are local franchises / stand-alone stores for Amsoil, Intestate batteroes , Goodyear tires, Starbucks.... :-) :-) , but Bosch injection parts ? Though maybe with the serial / model number off the ICV I can find one on the web ..

Partial Post: Please Login or Register to read the full post.

[unknown4u]

Yep bosch service station . Well known in Europe.

Partial Post: Please Login or Register to read the full post.

[flash]

wow - never heard of that here

Partial Post: Please Login or Register to read the full post.

[ds968]

Checked - no such things apparently exist here in the U.S.   There is Bosch-direct website but they do show this particular model number among what they carry - the part number ( imprinted on the valve itself ) is 0280140536 .   The dealers list price is $ 580 + tax , so over $ 600, but I identified 2 dealers that are willing to discount it to $ 452 + tax.    Still checking to see if the guy who rebuilt my engine has a good used one available - at last check he had two on the shelf but that was a couple of months ago.  Of course hard to test it unless it's in a car and you see how it does on a cold day's first start, but I think I'll take a chance ..I mean, what would be the probability of getting another one which a glitch ?!  I understand these things almost never go bad , But of course given that it's MY tiptronic, where practically every single component has gone wonky, why should I be surprised, this may be THE one exception out of 12,000 + cars .. ?!     

          

Partial Post: Please Login or Register to read the full post.

[ds968]

Gettimg closer to a resolution, but in the meantime this experience has reaffirmed the old adage about the difference between Japanese and German engineering mottos ; Japanese engineer : " if it doesn't break no need to fix it " German engineer : " If it doesn't break , it doesn't have enough components ! "

Partial Post: Please Login or Register to read the full post.

[Waylander]

My ICV was leaking air badly, I took it to bits and there is an o ring in the motor body in mine it was rotted away, new o ring and a good clean it's been fine

Partial Post: Please Login or Register to read the full post.

[ds968]

Well, it's fixed ! ( I think ) , but won't be able to test just how well it's really fixed until next winter when the nights and mornings are much , much colder . For now , in quasi-cool morning starts it idles perfectly fine ( a hair under 900, so guessing at 880 where a tiptronic should be ) can be driven off within seconds so no need for a warm-up period, so all good . Just don't ask me what the key problem was because an entire series of parts were gradually replaced so it's possible more than just one contributed to the issue, but to recap : temp sensor changed, O2 sensor changed, corroded wiring and the bad contacts / broken connector cap at the ICV changed, throttle plate returned to fully closed position ( I had the screw set for a higher idle than normal ) and a replacement chip with a confirmed 880 cold start rpm mapping installed in the DME . The ICV was NOT replaced , just removed and inspected, but it looked very clean and seemed to function fine ( verified by the Durametric test , as well as manual test ) . Time will tell ...

Partial Post: Please Login or Register to read the full post.

[brettestewart]

My 93 Cab likes to start out in 2nd gear when in D unless I really jump on the pedal off the line, then it kicks down to 1. In tiptronic mode, I can tap it into first at a stoplight, but it will always pop back into 2 when in D. Interestingly enough, when I select 3rd gear (not Tip) at a stoplight, the indicator will show it in first.

Anyone else have this issue?

Partial Post: Please Login or Register to read the full post.

[az968]

That's normal start for a tip, always 2nd gear unless forced into 1st manually or with throttle.

Partial Post: Please Login or Register to read the full post.

[ds968]

Correct.


( I was informed that was deigned in order to extend the life of the flex plate as long as possible . Of course if you're in tip / manual

mode and start in first gear all the time and stomping on it off the line frequently , you can reasonable expect no more than half of that dampner plate's typical longevity ).

Partial Post: Please Login or Register to read the full post.

[az968]

Moral to the story: don't drive like DS968

Partial Post: Please Login or Register to read the full post.

[ds968]

Moral to the story: don't drive like DS968

For the record , and quite honestly, if I stomped on tne gas pedal ( all the way to the floor ) once in every one thousand takeoffs from a dead stop, it would probably be one too many . I certainly have NEVER done that with the tiptronic, and even with the six speed it would be an extreme rarity. Having said that, once the car is rolling it's just as rare if I don't floor that pedal. and I do stomp on it as often as possible. The issue with the tiptronic is when you're not driving in tip / manual mode and just cruise along in regular " D " ...at various points when you stomp on it it'll downshift two whole gears , and even with a NA engine it's probably not healthy for the flex plate, but with 300 ft/lbs of torque the SC generates, if yiou do that frequentky enough you better budget a decent chunk of change for an annual replacement of that plate .

Partial Post: Please Login or Register to read the full post.

[ds968]

Well, it's fixed ! ( I think ) , but won't be able to test just how well it's really fixed until next winter when the nights and mornings are much , much colder . For now , in quasi-cool morning starts it idles perfectly fine ( a hair under 900, so guessing at 880 where a tiptronic should be ) can be driven off within seconds so no need for a warm-up period, so all good . Just don't ask me what the key problem was because an entire series of parts were gradually replaced so it's possible more than just one contributed to the issue, but to recap : temp sensor changed, O2 sensor changed, corroded wiring and the bad contacts / broken connector cap at the ICV changed, throttle plate returned to fully closed position ( I had the screw set for a higher idle than normal ) and a replacement chip with a confirmed 880 cold start rpm mapping installed in the DME . The ICV was NOT replaced , just removed and inspected, but it looked very clean and seemed to function fine ( verified by the Durametric test , as well as manual test ) . Time will tell ...

Follow up to the above - another month of troubleshooting , vacuum testing, more parts temporarily changed from another well running 968 ( a second ICV, another MAF, spark plugs, plug wires, coil , etc ) to test if any of those in my car are going bad, but no luck at all . Unbelievable !! The mechanic read on another forum that if the alternator is bad, that could also cause rough starts which can easily last five minutes or more .. That sounds very implausible to me , but since I know zero about mechanical dynamics does that make sense to anyone here ? I know I do have a bad alternator because the bearings make a lot of noise when the car is still cold ..a lot of noise ! But the alternator charges very well ( I changed the voltage regulator on it a whole ago ) , the charging has been tested including during cracking , but in spite of it functioning perfectly fine in that particular respect , could its bad bearings or whatever makes noise inside it, cause really bad , rough starts ?! Not really crazy about the idea of changing the alternator - with the SC in the way, that's a monumental job - just as a testing method, unless the theory of an alternator causing that problem is rock solid , or better yet proven .

Partial Post: Please Login or Register to read the full post.

[Waylander]

Don’t believe that for a second, bad alternator would cause issues all the time, I would be replacing the crank position sensor

Partial Post: Please Login or Register to read the full post.

[ds968]

And now it's been over two years since this ordeal started . After replacing practically every single component which could theoretically cause this cold start problem symptom, the mechanic is convinced that only two possibilities are left : the FPR or injectors are going bad, or ( what he claims is the more likely scenario ) the DME / chip has failed . So he's switching the DME from a stock Tiptronic which is running perfectly with my DME just to see if it makes any difference and eliminate that possibility . I'm concerned about running a stock chip in a SC's car, even if it's just a FPR a few days worth of test drives, but there's nothing left !!

Ugh, this has to be the most puzzling and frustrating experience I've had witn any car I have ever owned.

Partial Post: Please Login or Register to read the full post.

[flash]

NO!!!!!!!!  very very bad - do not run the car on the road with a stock chip on the supercharger.

 

first off, chips don't go bad like that.  when they fail, they fail completely.  besides, we already swapped out your chip once, when you were in my garage.

 

i told you to swap in a stock FPR to test.  do that first.

Partial Post: Please Login or Register to read the full post.

[ds968]

Got it. I forgot you telling me about the FPR, will try that. Maybe he did that on his own without me bringing it up, he said he tested or switched just about anything and everything that can be removed from the engine, but will double check with him .

Partial Post: Please Login or Register to read the full post.