John Speake

Hi Michael,
Yes.

bd0nalds0n

John, thanks for the clarification. The delay in the feedback loop you describe is similar to what I'm seeing. A blip on the throttle and my AF drops to somewhere in the 14-16 range (from 12:1 at idle) and within a second or two finds/hunts right around stoich.

heinrich

John ... where can I get good info on the Euros like yours, that use LH and MAF? I find almost nothing online!
All the best, and keep developing
Heinrich

John Speake

Hi Heinrich,
What kind of info are you after ? They are faily well covered in the Workshop manuals.

let me know.....

heinrich

John, I'm taken aback at the lack of photos, enthusiasts' pages, writeups, discussions etc on those models. I'll look at the manuals thanks, but I was hoping to find pics of engine bays; common problems; interior shots; discussions on tailpipe treatment and the subtle differences pointed out as compared to the earlier cars ..... pretty much what's available in abundance for my other cars

John Speake

Hi Heinrich,
Well, you're correct, they are not well covered for that kind of general information. There are of course the road tests of the 84-86 period that the Euro S2 was available.

One reason for the lack of much info is that there were only 989 cars of this type sold into the UK over these three years !

As far as I know the LH 16v was only sold into the UK, most of Europe had the L Jet with cats.

I expect you know the Euro S2 in '86 was the equivalent of the US "86.5" 32v, in that is had the S4 seats, front suspension and brakes.

If you want copies of the road tests I have, let me know.

I think most of the S2 Euros that ended up in the US were adapted to run with cats and O2 loop, but to the best of my knowledge this was not available in Europe.

What year Euro LH do you own ?

heinrich

THank you much John I just received my 1985 Euro S which has been through a bit, but I think will clean up nicely. I'll post pics tonight on a new thread.
Cheers,
Heinrich

klatinn

Only partially true. Most 'current feedback' WB METERS react slower due to the delay in their feedback loop. This delay is caused by the meter, not the sensor. The Bosch WB sensors themselves are actually as fast or faster than a typical NBO2. The LM-1 does not use the usual 'current feedback' loop, but uses a different (pat. pend.) measurement principle and therefore reacts with the inherent speed of the sensor itself. One characteristic of NBO2 sensors is that they get slower with age (like people). When slow response is seen, it can be due to a NBO2 at the end of it's useful life.

Regards,
Klaus

Tony

Klaus! long time no hear

This guy knows his stuff!
Hes been a great source of info for me with answers to my LM1

FYI, theres a few of us on here using the LM-1 for set ups and tuning.
great device!

mspiegle

very good info. thanks for the education

klatinn

Hey,

I love Porsches, grew up about 6 miles from Weissach and still have many friends there. The LM-1 was originally developed for my own Porsche powered vehicle (68 VW bus camper with 3.0 CIS engine, on it's way to EFI, turbo, AWIC and WI).

Regards,
Klaus

Lorenfb

"My guess is that instant 1/2 throttle doesn't trip the WOT switch and the ECU doesn't widen the pulse width of the injectors. Instant full throttle gives the wide pulse width right away providing you with a rich mixture instantly."

The LH unit (any ECM) will always increase the injection pulse width during an acceleration
(or throttle movement) just as the carbs did via the accel pump. Obviously, the amount of the
pulse width incease is a function of the throttle opening change, i.e. the load change
that the ECM determines. Without extra fuel to compensate for the extra air at the
"delta" throttle opening, as lean condition would occur, e.g. backfire.

At this time the ECM feedback system via the O2 sensor goes open-loop until a "steady state"
re-occurs, e.g. cruising. Once WOT occurs, even at cruising, the ECM system runs open-loop.