[flash]

for 5 years now i have felt that my car seemed to be doing a one step forward, two steps back thing - while i would gain upper end horsepower, i would seemingly lose low end torque

also, i would periodically get a variocam intermittent fault code when i did a blink test - no other faults - no check engine light - no big red light - i presumed a loose connection, fiddled with it and the hall sensor, which i knew to have a crumbly connector, and things "seemed" ok afterward

about 2 weeks ago, i was driving the car, and it really seemed limp, especially between 2k and 4k - this had happened before, but i chalked it up to cars running differently on different days - however, this was more so than i had remembered before - still though, no check engine light - no big red light (didn't do a blink test) - i was pretty disgusted and really feeling like maybe i was about done with this car

then, while out the other day with t-bone, the car suddenly developed a new symptom - at about 5k it felt like somebody had smacked the car - BAM! - it was far worse than the fuel cutout of over-rev - i let it back down, brought it back up - BAM! - it also idled a little high and chugged pretty bad off the line - ok - back to the garage

this time i plugged in the laptop and pulled the codes with the durametric - HALL SENDER and MAF - what the heck?

i had just cleaned the MAF and air filter, so i figured maybe i got something on it - cleaned the MAF again

the hall sender was disconnected, so i reconnected it - i figured that was it

reset the codes - run it again - HALL SENDER - crap

inspected the connector and wire - wire was crimped under the valve cover - must have done it when i did the belts - ok - damaged wire - cut out the bad wire and put in new wire - change connector while we're at it - put it back together - fire it up - HALL SENDER - crap!

take it all apart again - this time let's remove the sender and get better access - BINGO! shattered hall sender - ok - order a new one

today i finally got her buttoned back up, and took it for a quick spin - WOOHOO!! - this thing is a rocket! before when i would step on it at 2.5k in 4th it would just sit there - now it actually pulls - it pushed me back in the seat and everything - it's not like rubber burning V8 power, but it is really very nice - it pulls straight up and through, much smoother now as it crosses over the boost point of 4.3 and goes straight to redline - i had to back out of it in a hurry - very much more fun now

ok - maybe i'll keep it

bugs me that the car can have something like this wrong with it, and you never know about it - it took the durametric to figure it out - best thing i've done in a while

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[ds968]

sweeet !!

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[Cloud9...68]

Great find - must be very satisfying. My life flashed before my eyes for a split second at the thought of you being "done with this car" - the economy will get back on track one of these days, freeing up the cash needed for many of us to buy the wonderful creations you've come up with.

As far as your problem, a few questions. First and foremost, what the heck is a duramec? How/where do you "plug it in?" How long do you think you'd had the problem with the hall sender? If you think it's been an issue for awhile, do you think it was a confounding factor in the results you've seen with many of the exhausts you've tested over the last few years?

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[rhudeboye]

your quite good at tracking these things down in a logical manner. When all is done around the home, I plan to learn a bit more about fixing my car on my own.

Its also reassuring to see that even an experienced hand cant always nail it for or second try.

Good work and nice post.

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[flash]

durametric - diagnostic kit - uses a laptop - plugs into OBD1 port under the dash

how long has it been going on? probably on and off for 5 years - the good news is that the testing and stuff was not only on my car - i never relied on one car for any formal testing - i always used multiple cars in the tests so as to validate them

could i possibly find more now? who knows? for now i'm going to have fun driving it

a couple of small things to take care of, and i think i might actually have a decent fall of driving

until today, i wondered which car was quicker between the M3 and the 968 - not anymore - and i know exactly how quick that car is, so i am really looking forward to some timed runs in the near future - gonna have to wait probably 2 weeks though - they are tearing out the cul-de-sac in front of my house on wednesday, pinning the car in the garage, and i won't have time to get to it between now and then

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[Cloud9...68]

Hmmm... Funny how in all the discussions about the Bosch Hammer, and home-made versions thereof, I never saw anything about the durametric. Sounds like a very valuable tool. I'll have to look into it (although my car isn't displaying any obvious symptoms that would require disgnostics at the moment).

Anyway, congrats on tracking down your problem.

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[PorscheDude]

Awesome! Glad that the cure was found.

You must be stoked!

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[flash]

i am - the odd thing was that nothing seemed really all that out of the ordinary for so long - it ran fine really - it was so subtle that i chalked it up to other stuff - but man what a change - can't wait to drive it tomorrow

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[ds968]

Yeah, it pisses me off that Porsche could not simply program in a trigger mechanism ( CEL comes on, for example ) any time a single one of the covered faults which can be diagnosed by the blink test may malfunction.. even a little. As Bob experienced, some of the symptoms from intermittent failures of one component or another may not be necessarily be pronounced enough to alert you there is something wrong, yet you can be robbed of 5 or 10 or who knows what of hp and torque and without doing a blink test every single time you get in the car [img]style_emoticons/<#EMO_DIR#>/dry.gif[/img] , you'll never know..

how difficult would it have been to friggin' program something as simple as a light alert off an already established diagnoostic test system ?! [img]style_emoticons/<#EMO_DIR#>/mad.gif[/img]

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[flash]

yeah - that part sucks - all this time and i could have been having a LOT more fun - i just didn't know it until now

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[Johannvb]

I'm glad your car if fixed! Was this a tough DIY?

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[flash]

not at all, had i not have had to hack into it - if it was a straight forward component swap, it would have been less than 1/2 hour

remove valve cover - remove 2 screws at the back of the distrbutor - unplug cable - remove sender - plug in new sender, reverse order to reassemble

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[Johannvb]

I have actually been contemplating replacing all the major sensors and electrical components in the car. Every time I replace a sensor or other electrical part it is like the car becomes a couple of years younger. Maybe 15 years is just the age at which all the electrical components starts failing.

I am ordering a new coil and fuel pump + regulator within the next month, and now that I read your post I might just order a new Hall Sender as well.

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[flash]

the hall sender is one that is particularly subject to failure - this is due to the incredible heat coming up from the exhaust manifold - i cannot for the life of me figure out why they put both that and the heater control valve right there - both plastic parts - both right above something that regularly shows 400 degree heat - what were they thinking?

this is exactly why i came up with the heat shield - i just wish i had done it before i had cooked both of those parts

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[flash]

ok - second drive - ran around for about 45 minutes putting a charge on the new yellow top

impressions:

with everything working now, the power curve is much more linear - i had a very abrupt climb after 4300 before - definitely still picks up there, but it is MUCH smoother getting to that point - nice strong pull all the way up

ridiculously fast through the gears now - much stronger - i took one of my favorite on ramps today and was a good 10mph faster at the end than i was before - much more fun - and where before it really felt like i was winding it out, now it just felt happy

yeah, i'd still like another 30hp or so, but i am quite pleased now - i'll get that 30 when i bore it out and do a bit of head work - i can wait - until then, i think i will just enjoy the car

3 small things left to take care of - trickle charger, one squeak, and figure out why my bluetooth quit working

not a bad list - should be easy stuff

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[timbits]

<!--quoteo(post=78504:date=Aug 23 2009, 01:10 PM:name=flash)-->QUOTE (flash @ Aug 23 2009, 01:10 PM) <{POST_SNAPBACK}><!--quotec-->the hall sender is one that is particularly subject to failure - this is due to the incredible heat coming up from the exhaust manifold - i cannot for the life of me figure out why they put both that and the heater control valve right there - both plastic parts - both right above something that regularly shows 400 degree heat - what were they thinking?

this is exactly why i came up with the heat shield - i just wish i had done it before i had cooked both of those parts<!--QuoteEnd--><!--QuoteEEnd-->

Agreed. 15 years of getting heated by the exhaust and my HCV goes out on me the other week when I'm on the track. This made me realize that it's time for some preventative TLC so now I'm working at replacing parts all over the car. HCV is done. My clutch is starting to act up on me so the master and slave clyinders are going along with the hoses (yay for RSBarn SS Line [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]). New RSBarn SS brake lines are on their way since I don't know how old the current ones are and they feel a bit mushy on the track even with brand new brake fluid. And now I'm going to add the hall sensor to the list.
It may not be totally gone on my car yet, but the deadness of power sounds like what flash was seeing and I can't imagine it's in great shape after all these years especially when other parts are starting to go. It's not a terribly expensive part so it's worth it to me for the peace of mind.

Tim

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[flash]

since you have now replaced the HCV and are now replacing the hall sender, stick that heat shield in there and you should be good to go for a very long time

one thing i have learned from this is that i need to drive the car more - i made so many changes, and never really drove it to have a decent sampling of a control state, that i chalked things up to the changes - i let myself be convinced that things were ok, given that there were no lights lit and no obvious symptoms

i just may take the 968 to go play golf tomorrow

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[ds968]

<!--quoteo(post=78505:date=Aug 23 2009, 02:21 PM:name=flash)-->QUOTE (flash @ Aug 23 2009, 02:21 PM) <{POST_SNAPBACK}><!--quotec-->with everything working now, the power curve is much more linear - i had a very abrupt climb after 4300 before - definitely still picks up there, but it is MUCH smoother getting to that point - nice strong pull all the way up<!--QuoteEnd--><!--QuoteEEnd-->


Interesting that this is the EXACT effect I am experiencing after the valve job.

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[Cloud9...68]

Just to clarify, are the hall sensor and hall sender one and the same, or are they two different things? My understanding is that the hall sensor sits on the right side of the ending, near the HCV, and its case tends to crumble from the heat (mine definitely has). But Flash described the hall sender as being behind the distributor, which is close to where I thought the hall sensor is, but not exactly. Thanks.

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[PorscheDude]

It's sits behind the cam gear inside the cam gear housing.
The back side of the connector is right next the HCV.

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