Rennlist - Porsche Discussion Forums

Rennlist - Porsche Discussion Forums (https://rennlist.com/forums/)
-   928 Forum (https://rennlist.com/forums/928-forum-69/)
-   -   '84 - '86 Euro owners beware (https://rennlist.com/forums/928-forum/219931-84-86-euro-owners-beware.html)

Rich9928p 08-06-2005 11:37 PM

'84 - '86 Euro owners beware
 
A customer sent me his '84 Euro LH fuel injection module for repair. It was strange situation, the original LH module failed after the PO had close to $5000 work done on the 928. A used replacement LH failed within six months of replacement.

The LH module had burned out power transistors, not a normal problem. I cautioned the customer to check the fuel injectors (for LH systems, about 16 Ohms) and to inspect the wiring harness for shorts before installing the rebuilt unit.

The result of the customer's inspection was surprising, the fuel injectors measured 3.2 - 3.3 Ohms vs. the expected 16 Ohms. A check of the part number proved that the repair shop installed the WRONG fuel injectors for a Euro - yes, they were for an '84 but not for an LH system - they were for the US L-Jet system. The wrong injectors had too low resistance, too much current flowed into the LH, and two LH modules were damaged. If the customer had installed the rebuilt unit, once again he would have a failed LH. The fuel injection wiring harness may also be damaged from too much current flow.

So, if you have your Euro 928 worked on, be sure that the shop understands the difference between the US and Euro versions. If you repair your own 928, be sure that your parts vendor knows it is a Euro and provides the correct parts, injectors for this Euro are 928.606.119.00 (Bosch P/N 0280.150.252). Very costly mistakes can be eliminated.

Here is another hint. The '84 - 86 Euros have two 4 cylinder distributors grafted together. There is a belt from main rotor shaft that drives the 2nd distributor. If that belt snaps, the engine will only run on 4 cylinders and you have a danger of a fuel fire caused by unburned fuel igniting in the exhaust. If you experience a rapid loss of power, shut down the engine immediately and have it towed in. Don't try to limp home!

FlyingDog 08-07-2005 12:15 AM

Goog to know on the injectors. Are they the same as 32V injectors?

Originally Posted by Rich9928p
Here is another hint. The '84 - 86 Euros have two 4 cylinder distributors grafted together. There is a belt from main rotor shaft that drives the 2nd distributor. If that belt snaps, the engine will only run on 4 cylinders and you have a danger of a fuel fire caused by unburned fuel igniting in the exhaust. If you experience a rapid loss of power, shut down the engine immediately and have it towed in. Don't try to limp home!

BTDT x 3 belts
BTDT x 1 fire

Rich9928p 08-07-2005 12:21 AM


Originally Posted by FlyingDog
Goog to know on the injectors. Are they the same as 32V injectors?BTDT x 3 belts
BTDT x 1 fire

I got these part numbers from the factory workshop manuals. It would be good to check with your vendor to be sure they have not been superceded.

1. 1980 to 1984 US L-Jet Fuel Injector P/N: 928.606.110.01
Bosch P/N 0280.150.154

2. 1984 to 1986 (Euro) LH Jet Fuel Injector P/N: 928.606.119.00
Bosch P/N 0280.150.252

3. US Spec 1985 and 1986 LH Jet Fuel Injector P/N: 928.606.120.00
Bosch P/N 0280.150.706

4. 1987 and newer LH Fuel Injector P/N: 928.606.119.02
Bosch P/N 0280.150.730

Rich9928p 08-08-2005 04:15 AM

Here is a bit more trivia for you Euro 928 owners. The first generation 25 pin LH for your cars has no lambda regulation (O2 sensor and feedback circuit) nor idle speed regulation. If you look to the circuit board the area is devoid of the components that make that happen.

The US 1985 - 86 25 pin LH variants have a faster clock speed on the 8039 microcontroller and include Lambda and idle speed regulation functions and the related circuits populated. For these reasons, the LH units are not interchangeable, even though they look the same at the plug. The ROM chips are not interchangeable either. So don't try to plug in one of those aftermarket chips unless they specifically state they work for the Euro motor!

John Speake 08-08-2005 05:55 AM

Will the US version work on a Euro if you change the clock speed ?

Red UFO 08-08-2005 11:16 AM

Damn rich you booga booga my Euro now.

Rich9928p 08-08-2005 07:45 PM


Originally Posted by John Speake
Will the US version work on a Euro if you change the clock speed ?

John,

The Euro LH board that I rebuilt had unpopulated areas for resistors and transistors associated with idle regulation and lambda regulation. I compared it to a US-spec LH that I have on-hand and it was a different revision board (several components were in different locations).

I've heard that my German colleague has updated old 25 pin LHs to support Lambda and idle speed, so it should be possible to go the other way.

Rich9928p 08-08-2005 07:53 PM


Originally Posted by Red UFO
Damn rich you booga booga my Euro now.

I control the vertical, I control the horizonal, I can turn your Euro into a soft blur ....

Normy 08-08-2005 07:56 PM

My ROW '85 car drove around for years [apparently] with a US 32 valve '85 LH controller!

John Speake was able to burn me a chip with the S2 specification; I installed it in my US '85 box when I discovered this fact. It runs great- in fact there was a notable improvement in driveability versus the old US chip.

Question: I'm driving around with a "converted" LH box, perhaps the only one in the world. This seems to work well.... better than the US box/chip worked on this car. But is it running correctly? I can't complain about the performance of this car lately; a little heavy on fuel use, but good power...

[No cat, no lambda]

N!

Normy 08-08-2005 08:07 PM

Tom- get your ass out into that garage right now and check to make sure your LH controller hasn't failed at some time in the past and some mindless idiot at a Porsche dealer somewhere hasn't installed a US '85 LH box in your car the way that someone apparently did in mine!

ROW part number: 928.618.123.02

US part number: 928.618.123.04

!

N-

Red UFO 08-08-2005 08:28 PM

I think Rich checked it out and would know. I know nothing of that stuff. Hell my Euro won't run for atleast week until I get done messing with it.

Rich9928p 08-08-2005 09:04 PM


Originally Posted by Normy
My ROW '85 car drove around for years [apparently] with a US 32 valve '85 LH controller!

John Speake was able to burn me a chip with the S2 specification; I installed it in my US '85 box when I discovered this fact. It runs great- in fact there was a notable improvement in driveability versus the old US chip.

Question: I'm driving around with a "converted" LH box, perhaps the only one in the world. This seems to work well.... better than the US box/chip worked on this car. But is it running correctly? I can't complain about the performance of this car lately; a little heavy on fuel use, but good power...

[No cat, no lambda]

N!

I guess you'd get better performance, the LH was looking for lambda feedback and it wasn't getting any, so it may have defaulted to a "fail safe" mode.

You're also lucky that someone didn't try plugging a US spec ROM into a EURO LH that doesn't have idle speed and lambda circuits populated, that could cause some problems. I would imagine Euro LHs had the slower 8039, and the clock speed update was necessary to manage the additional features; idle speed and lambda. Perhaps Bosch wrote the code to function independent of the clock speed, so a faster microcontroller running "old Euro" code makes no difference (but a slower couldn't keep up with the additional functions!!).

Normy, I hope your 747s have the correct modules. Don't try flying a 747-400 with 747 classic electronics!!!! I think the FE must do some work on those old birds.

Normy 08-08-2005 09:19 PM


Originally Posted by Rich9928p
I guess you'd get better performance, the LH was looking for lambda feedback and it wasn't getting any, so it may have defaulted to a "fail safe" mode.

You're also lucky that someone didn't try plugging a US spec ROM into a EURO LH that doesn't have idle speed and lambda circuits populated, that could cause some problems. I would imagine Euro LHs had the slower 8039, and the clock speed update was necessary to manage the additional features; idle speed and lambda. Perhaps Bosch wrote the code to function independent of the clock speed, so a faster microcontroller running "old Euro" code makes no difference (but a slower couldn't keep up with the additional functions!!).

Normy, I hope your 747s have the correct modules. Don't try flying a 747-400 with 747 classic electronics!!!! I think the FE must do some work on those old birds.

Perhaps. I doubt most Porsche mechanics were able to burn chips for oddball European cars back when I bought this thing. An '85 928 comes in the shop, and needs a new computer. They order one and install it; Out the door it goes-

I take off, I fly...I land. I don't want to know what lurks down in "lower 41", the electronics bay, since I'm sure there are some "creative" solutions to maintenance problems to be found there ...

[Our tech's are actually pretty good with these ancient beasts; they "re-rack" or remove/clean/reinstall a lot of connectors, but generally the planes don't give us much real trouble, despite being 30+ years old]

And you certainly can't use -400 electronics in a -200 airframe! [Good analogy, but the -400 was built with 1985 technology...] But you can use US parts in a "Euro" [creating problems], or Euro parts in a US car. I always wondered if the S2 chip would work in a US '85 car. S2's have fueling problems, with a tendency to go lean, though that's not my experience at all- just the opposite in fact. The chip that Speake burned for me raised my rev-limiter from about 6000 rpm to around 6500, and gave me better overall performance.

N!

N!

Red UFO 08-09-2005 03:12 AM

Whats messed up is I have more 'fun' taking this car apart, messing with it, seeing how it works or fixing something I think should, than I do driving the damn thing.

I'm getting paranoid (insert joke ______) that as soon as I get his Euro perfect with chrome spider, DVD player, Heinrich's rims, R2-D2 telling cops to go F themself, missiles, range finder, lasers, and telescope, night vision, that somebody in a H2 will crash into me and break my **** weeks after its perfected.

http://forums.rennlist.com/upload/r2.jpg

John Speake 08-09-2005 06:10 AM

QUOTE -The Euro LH board that I rebuilt had unpopulated areas for resistors and transistors associated with idle regulation and lambda regulation. I compared it to a US-spec LH that I have on-hand and it was a different revision board (several components were in different locations).

I've heard that my German colleague has updated old 25 pin LHs to support Lambda and idle speed, so it should be possible to go the other way.
>>>>>>>>>>>>>>>
Thanks Rich,
LH 2.2's are pretty reliable, so I don't repair them. But I have now heard of several that are failing on the rpm interface between the EZK and LH. The strange thing about this is that this only appears to happen to manual gearbox cars. As the kickdown relaly which has a rpm feed is connected to this interface, I can only assume there is a leakage problem in the manual cars that develops over time....I am thinking this is on the LH input, rather than the EZK ouitput...

I bought a pair of US LH 2.2 EZK/LH ECUs and would like to make them usuable on my Euro S2.

Regards


All times are GMT -3. The time now is 08:11 PM.


© 2019 MH Sub I, LLC dba Internet Brands