broken...diagnosed...fixed!!! (bad LH computer - RV)
08-09-2006, 06:29 PM
#16
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Originally Posted by 928andRC51
Sunday: Car almost completely not running, with no warning.
Monday: Called Dave Chamberland, he arrived and within 1 minute had diagnosed a bad LH computer. Called Rich Andrade and he had a rebuilt LH on it's way within minutes.
Tuesday: Received the LH, swapped into the car, now it runs great.
Funny, Dave C. had warned me to have the LH rebuilt last winter,.....and I didn't do it.
Dave C.
Rich9928 Andrade:
We have a lot of great resources among us, for sure.
Monday: Called Dave Chamberland, he arrived and within 1 minute had diagnosed a bad LH computer. Called Rich Andrade and he had a rebuilt LH on it's way within minutes.
Tuesday: Received the LH, swapped into the car, now it runs great.
Funny, Dave C. had warned me to have the LH rebuilt last winter,.....and I didn't do it.
Dave C.
Rich9928 Andrade:
We have a lot of great resources among us, for sure.
Glad to have helped! You can make your trip up north with no delay. Nothing like driving a 928 with one less worry!
08-09-2006, 06:31 PM
#17
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Originally Posted by dr bob
There's a real case for prophylactic rebuild, especially for cars that get stored during the off season. Pull the brain sometime in the fall, and have it renewed and back in before the spring thaw.
Beats getting stranded someplace. As you know, it's a matter of "when" and not really "IF". My luck says that I would be stranded on a hot desert highway at night. I know I'll need the replacement soon, based on statistics. So I had a spare one rebuilt, heading off disaster. Of course, with a spare in the ready, the old one will run forever. No spare, and you are just another sob story waiting to be told.
Beats getting stranded someplace. As you know, it's a matter of "when" and not really "IF". My luck says that I would be stranded on a hot desert highway at night. I know I'll need the replacement soon, based on statistics. So I had a spare one rebuilt, heading off disaster. Of course, with a spare in the ready, the old one will run forever. No spare, and you are just another sob story waiting to be told.
08-09-2006, 07:26 PM
#18
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Originally Posted by Rich9928p
Bob, that is a very wise recommendation. I'll bet you are wise enought to have done this already
You --might-- break even on that bet. The 'new' abby-something brain is in the back of the car. I guess I should just put it in and send you the old one that still works. I was holding off on that, on the chance that a local owner needed a test brain. While the old one is in the car and it drives, I know it makes an OK loaner.
We should talk off-list about options I guess. Need a local "test agent" in the L.A. basin?
08-09-2006, 07:38 PM
#19
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Originally Posted by littleball_s4
Sorry for little OT:
I can get a cheap used LH from a 88 s4 auto which, sadly, doesn't need it any more. My car is a 87 s4 5spd.
I recall both MY are a little bit different, although interchangeable, and I know there is a jumper panel to tell the LH several things -such as the tranny type?-, but I don't have the manuals with me and I dont want to fry anything:
Can I simply swap both to test (before purchasing)? If not, is it an easy way?
Thx!
I can get a cheap used LH from a 88 s4 auto which, sadly, doesn't need it any more. My car is a 87 s4 5spd.
I recall both MY are a little bit different, although interchangeable, and I know there is a jumper panel to tell the LH several things -such as the tranny type?-, but I don't have the manuals with me and I dont want to fry anything:
Can I simply swap both to test (before purchasing)? If not, is it an easy way?
Thx!
The codeing plug ( jumper panel referred to) stays with your car when the LH is swapped - so no problems: the '88 LH will work in your '87.
BYW, the code plug is a serarate harness that clips to the frame that contains the EZK & LH. IIRC, the only difference in the '88 is the access for the Bosch Hammer diagnostic port.
08-09-2006, 11:37 PM
#20
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Originally Posted by Bill Ball
How did Dave diagnose it in 1 minute?
a) cause I've fixed just about damn-near-everything else under the hood on Carl's car
b) The symptoms Carl described to me on the phone were consistent with LH brain death
c) With the key on the injectors clicked like mad.
d) all of the above.
I arrived with my housecall no-start/runs-like-crap goodie box (laptop, relays, MAS, LH, ignition stages, portable 'scope, DMM, noid light, etc.) and was prepared to go deep. But, I was pretty sure it was the LH from what Carl told me. I need to add a speed sensor to the kit. I would have loaned Carl my spare LH but I needed it for the 6-hours-from-home business trip I'm on now. Since I carry the spare around when I drive more than an hour or three from home I know my LH will never fail when I'm on a long trip.
Last edited by worf928; 08-10-2006 at 07:06 AM.
08-10-2006, 02:25 AM
#21
"The major failure is the hybrid circuit - a custom part that is not sold as a replacement item. It fails as a function of module age, not miles."
Age can be a factor, but's it's NOT as much of a key factor as over-voltaging of
the LH unit as the hybrid is not protected from over-voltage (poor design),
e.g. battery chargers (strong unit with a totally dead battery) and/or an
over-charging alternator. Also, an inductive "kick" from a bad starter can cause
a voltage transient which results in an over-voltage condition.
Many failures occur as described above after setting in a garage
for the winter (non-use) and a charger and/or a jump start is used.
Furthermore, the statement that all LH units will fail is total B.S.
Like all systems, there's a probability of failure and it's NOT 1.0,
nor is it even close to 1.0.
Note: Make sure that your rebuilt unit has the updated module replacement for
the problematic hybrid. Not all replacement parts are equal.
Age can be a factor, but's it's NOT as much of a key factor as over-voltaging of
the LH unit as the hybrid is not protected from over-voltage (poor design),
e.g. battery chargers (strong unit with a totally dead battery) and/or an
over-charging alternator. Also, an inductive "kick" from a bad starter can cause
a voltage transient which results in an over-voltage condition.
Many failures occur as described above after setting in a garage
for the winter (non-use) and a charger and/or a jump start is used.
Furthermore, the statement that all LH units will fail is total B.S.
Like all systems, there's a probability of failure and it's NOT 1.0,
nor is it even close to 1.0.
Note: Make sure that your rebuilt unit has the updated module replacement for
the problematic hybrid. Not all replacement parts are equal.
08-10-2006, 04:21 AM
#22
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Originally Posted by Garth S
The codeing plug ( jumper panel referred to) stays with your car when the LH is swapped - so no problems: the '88 LH will work in your '87.
BYW, the code plug is a serarate harness that clips to the frame that contains the EZK & LH. IIRC, the only difference in the '88 is the access for the Bosch Hammer diagnostic port.
BYW, the code plug is a serarate harness that clips to the frame that contains the EZK & LH. IIRC, the only difference in the '88 is the access for the Bosch Hammer diagnostic port.
