1974 914 1.8, the mystery of the EC-A and EC-B Options

[Van B]

Here’s my rain tray. All original, all philips head metric fine pitch, no stand offs, and not even removed when they did the garbage paint job some years back

[StarBear]

Fellas!

NOS TTS for our cars on ebay:
https://www.ebay.com/itm/255490292323

I bought one so… three left!

Thanks! Thinking about it though at that price maybe hold off as just bought a $100 orbital polisher to do my windshield this winter.
How critical are these TTS, and do they fail often? Mostly for initial, cold starting?

BTW, checked PET page 124; the part numbers are different: 022 906 164 for ECO 037 551- and 043 906 163 for ECO 037 552+. Would this make a difference? 022 vs 043 just supplier part number (VW vs other?).

Also, I've never been quite sure, but is ECO 037... referencing the engine number? If so, what is the difference for a 1.8 at that split (551/552) in the numbering?
Still learning this stuff....
@wonkipop
@L-Jet914
@Van B

[wonkipop]

Fellas!

NOS TTS for our cars on ebay:
https://www.ebay.com/itm/255490292323

I bought one so… three left!

Thanks! Thinking about it though at that price maybe hold off as just bought a $100 orbital polisher to do my windshield this winter.
How critical are these TTS, and do they fail often? Mostly for initial, cold starting?

BTW, checked PET page 124; the part numbers are different: 022 906 164 for ECO 037 551- and 043 906 163 for ECO 037 552+. Would this make a difference? 022 vs 043 just supplier part number (VW vs other?).

Also, I've never been quite sure, but is ECO 037... referencing the engine number? If so, what is the difference for a 1.8 at that split (551/552) in the numbering?
Still learning this stuff....
@wonkipop
@L-Jet914
@Van B

yes its the engine number.
up to 551 is 74. from 552 on is 75.

regarding the first three numbers on the part number.
usually in VW parlance the first three numbers refer to the model the part was first used on. in this case however i don't see that for either of part numbers in PET for this thermo time switch. they do have other conventions on those first three numbers. belonging to a parts group etc.

so is the thermo time switch different for 74 to 75?
i'm going to guess its the same because i am pretty sure the cold start injector is the same and the TTS controls that. its only the first three numbers are different.
what would have possibly made it different. only emissions laws, some fine details on cold start warm up emissions? i don't think there was anything that fussy going down in 74/75.

anyway. i can do a bit more poking around on that but i am sure @Van B will have already done his research.

[Van B]

You both may remember all the learning I did sorting out the FI last year, but I’ll give the sort version.

When the TTS fails, your CSV will only work during cranking. Which means you don’t get the 8 sec extra when cold. The later versions for the 75 and 912E give you 13 sec.

So, in warm weather, TTS is irrelevant, but it’s an important part for cold mornings. It gets your RPMs up long enough to get the flow running through the AAR and open the barn door on the AFM.


Bosch and Porsche say this is the superseded part, which I bought, but it is digital circuits and I’m not sure it works correctly in our cars.
https://www.fcpeuro.com/products/bmw-thermo...sch-13621362599

[StarBear]

On the AA site it provides a 928 part number availability. Have seen that in a few other instances. Maybe a small difference in the eBay part number, bring Bosch instead of VW or other. I think I have an alternate parts listing, from Bowlsby IIRC.

[StarBear]

You both may remember all the learning I did sorting out the FI last year, but I’ll give the sort version.

When the TTS fails, your CSV will only work during cranking. Which means you don’t get the 8 sec extra when cold. The later versions for the 75 and 912E give you 13 sec.

So, in warm weather, TTS is irrelevant, but it’s an important part for cold mornings. It gets your RPMs up long enough to get the flow running through the AAR and open the barn door on the AFM.


Bosch and Porsche say this is the superseded part, which I bought, but it is digital circuits and I’m not sure it works correctly in our cars.
https://www.fcpeuro.com/products/bmw-thermo...sch-13621362599

(IMG:style_emoticons/default/pray.gif)
Will keep this in my reference notebook. Thanks!

[wonkipop]

You both may remember all the learning I did sorting out the FI last year, but I’ll give the sort version.

When the TTS fails, your CSV will only work during cranking. Which means you don’t get the 8 sec extra when cold. The later versions for the 75 and 912E give you 13 sec.

So, in warm weather, TTS is irrelevant, but it’s an important part for cold mornings. It gets your RPMs up long enough to get the flow running through the AAR and open the barn door on the AFM.


Bosch and Porsche say this is the superseded part, which I bought, but it is digital circuits and I’m not sure it works correctly in our cars.
https://www.fcpeuro.com/products/bmw-thermo...sch-13621362599

excellent summary.

i could half remember you had done all that homework @Van B .

i'll look into maybe picking one of these TTS. the aussie dollar is very weak against the USD at the moment so its a pretty expensive bit to pick up but i may just bite the bullet.

thanks for the tip off.

[StarBear]

Good thing I checked my stash inventory list - I already have a used/tested unit.
In the process, I seem to have taken good notes (see pics); in 1974 and earlier they used 022 for the fuel injection group, changing this part to the electrical group, 043, by July 74 (see pic with date) hence the change in part number. 13C and 8 secs as shown in pic.
As further pics show the 022/043 part number is VW/Audi; the 028 number is Bosch. Same unit. Should work just fine, @wonkipop .

[Van B]

Yeah that’ll do nicely. The resistor type are what our cars need. The new style with the long hex body don’t speak the same language.

[L-Jet914]

Fellas!

NOS TTS for our cars on ebay:
https://www.ebay.com/itm/255490292323

I bought one so… three left!

Thanks! Thinking about it though at that price maybe hold off as just bought a $100 orbital polisher to do my windshield this winter.
How critical are these TTS, and do they fail often? Mostly for initial, cold starting?

BTW, checked PET page 124; the part numbers are different: 022 906 164 for ECO 037 551- and 043 906 163 for ECO 037 552+. Would this make a difference? 022 vs 043 just supplier part number (VW vs other?).

Also, I've never been quite sure, but is ECO 037... referencing the engine number? If so, what is the difference for a 1.8 at that split (551/552) in the numbering?
Still learning this stuff....
@wonkipop
@L-Jet914
@Van B

The TTS complete with bracket, I acquired from Jeff Bowlsby as part of a L-Jet roadside fix it kit for the TTS shows VW PN: 022906163 Bosch PN: 0280130202 11/73 (build month?) and 15 degrees C 8 seconds.

[wonkipop]

EPILOGUE to the 74 L Jets with some information gathered along the way concerning the 75 L Jet 1.8s.

In 75 there again was 2 different versions of the 1.8 L Jet.
One for USA (49 states) and one for California.

@JeffBowlsby has a publication on his website which identifies these two different engines with non-clamenture similar but not identical to the 74 models.
The publication is MODEL 75, Service and Training Information.
on page 11 the following is listed.
EC-a (USA)
EC-b (California).
This is the only place this designation is found in literature to date.
note - it is the reverse of the notation for the 74 engines and lower case a and b is used instead of the upper case used in 74. in 74 the B was the USA engine and the A was the california spec engine.

For 1975 the production cars and CARB documents identify the engines instead using a new notation named Engine Family.

Engine Family 15 is the EC-a (USA engine).
Engine Family 16 is the EC-b (California engine).


--------------

Engine Family 15 and 16 engines are most obviously identified by 1) Emission Sticker and characterised by 2) Engine Tune-up Sticker, 3) painted number stamp and 4) the fitment of EGR and CAT in the case of californian spec cars.

---------------

ENGINE FAMILY 15. (49 states).

1. Emission Sticker.

Located on the cast fan shrounding, left hand side of engine.
USEPA compliant only.





2. Engine Tune-up Sticker.

Located on the upper tin-ware, left hand side of engine.
shows both vacuum hoses to distributor, both to be disconnected for tune-up.
(unlike 74 models both engine families had identical tune up stickers in 75).




3. Painted Stencil Number on Engine Tin.

located on either left hand side of engine,
or on both sides of engine. the engines are marked with either 918 or 920.
Similar to 74 cars the two different numbers designate whether the engine was fitted with the oil temp sensor sump lid and associated wiring (for console and gauge option) or the standard sump lid.
918 = standard sump lid cars (no temp gauge).
920 = oil temp sensor lid (console + gauge cars from factory).









4. Emission Equipment.

the engine family 15 (EC-a/49 states) engines are set up very similar (almost identical) to the 74 EC-A (california) cars. No vacuum advance port on throttle body and vac advance hose from distributor tucked under intake plenum. The decel valve was of a different design to the 74 cars. Charcoal Cannister location was altered to beside the battery. ECU and AFM was updated and was a different part # to 74 (though this may have occured early in the run of 75 models and not at the start of production, some 75s used the earlier AFM and ECU from the 74 until stocks were exhausted).





-----------

ENGINE FAMILY 16 (California)


1. Emission Sticker.

Located on fan shroud, Left hand side of engine.
USEPA and California Emissions compliant.




2. Tune-up Sticker.

Identical to eng. fam. 15 in same location.




3. Painted Stencil Number on Engine Tin.

Located on either left hand side of engine or on both sides of engine.
the engines are marked with either 919 or 921.
919 indicates standard sump lid engines (no temp gauge).
921 indicates oil temp sensor sum lid engines (console/gauges option from factory).







4. Emissions Equipment

the Engine Family 16 (EC-b/California) are set up with EGR (ex gas recirculation ) and a CAT. the EGR uses a throttle body similar (virtually identical) to the 74 EC-B (49 states engine), the TB has a vacuum port above the throttle body. the EGR is activated by a vacuum hose from that port and operates at times of high engine vacuum when not idling (ie highway cruise). the vacuum advance line from the distributor is not connected and is tucked under the intake plenum as per 74 EC-a engines and 75 E. F. 15 engines.
there are further detailed differences. unique distributor without ignition cut off rotor and a fuel cut off switch incorporated instead.
note - the position of this canister has likely been flipped 180 degrees to allow connection of a right hand side heater booster fan hose (non original-later dealer or owner modification) - the original hose connections have been maintained.

[wonkipop]

CARB documents covering the 1975 model year outline the differences in spec that cover Engine Family 16 cars for the californian market.

[L-Jet914]

hey hey hey stay out of my treasure trove carb archives (IMG:style_emoticons/default/wink.gif)

[wonkipop]

hey hey hey stay out of my treasure trove carb archives (IMG:style_emoticons/default/wink.gif)

let me into any archive and its all over. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/beerchug.gif)
thanks for the keys to that vault. (IMG:style_emoticons/default/beerchug.gif)

i never thought i would ever end up an emissions nerd.
but i have become fascinated by technology.
and its beginnings.
probably no different than being over interested in apollo moon mission technical artefacts. its a fascinating time in humanity when the 914 is in production.
up against the wall with the EPA really coming at them.
no different than LOR, lunar orbital rendezvous i have decided.
john houlbolt is one of my childhood heroes.
he stood up to werner von braun and the rest of them and told them he was right.
and he was.
basically the architect of the apollo design. at a concept design level.
which is what someone in germany was doing when they came up with L jet.
love to know who thought of L jet.
its the same heresy as LOR for the moon missions?

[wonkipop]

doing a bit of research.
images from the bundesarchiv (available from wikipedia).

914 on the VW banked test track.
date is interesting - Jan 1973.

they would not have been testing the 2.0 L engine at that time.
already in production. would have been earlier on that model.
all the early testing would have been done in 1968 on the original cars.

my bet (educated guess) is this is the L jet engine being tested.
probably on durability runs.

[wonkipop]

@StarBear

more 74 minutiae?
i recently collected some BAT data on 1.8
( a new member @Bwingate now has the car (IMG:style_emoticons/default/biggrin.gif) )
i noticed this. not something you normally pick re details. (IMG:style_emoticons/default/beer.gif)



can't tell if its my imagination or i am seeing what i think is there.
metal (chrome?) visor pins.
its a 11/73 car.

my car has black plastic visor pins. is a 01/74 build.
you have a 11/73 car @StarBear . what are the pins on yours.

@JeffBowlsby ?

[JeffBowlsby]

I have noticed that too. As far as I know they are chrome up to 73, then black 74+

[wonkipop]

and 74 esoteric stuff.

got hold of some further photos of Dr. Horst Marchart 74 1.8 from porsche museum.


dashboard detail.



at first i thought i was looking at an EGR light.
but........whats an EGR light doing on a 74 euro spec 1.8 with twin carbs and zero emissions gear?



and why does it look different to the real deal EGR / CAT lights that were in 75 cali 1.8s?



then i realised the EGR "light" in Dr. Marchart's car isn't a light its a mockup.
an orange printed label stuck to the dashboard face with a piece of circular transparent tape. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)
the designers/engineers at porsche must have been using Dr. Marchart's car to test out the positioning of the lights during 1974.
pretty amazing the artefact is still there stuck on the dashboard 50 years later.
probably had a CAT light mockup "light" as well but it peeled off somewhere down the years? (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)

----------

anyway i can date this car i reckon even without a VIN number.
thanks to all the minutiae we stumbled over with the L jet research.

front trunk.


black headlight side covers + all cardboard tubes to heater/fresh air box.
= pre jan 01 1974.
after jan 01 74 headlight covers are grey until april 74.
when black again post april the heater box tubes have been changed to black plastic.

rear trunk.



no small formed dent to carry the engine bay charcoal cannister.
even though euro spec cars did not have vapor emissions equipment fitted they used the same body shells as the USA spec cars. the dent was there after 18/19 Nov 1973.

here is a euro spec 75 german delivered.


USA spec 74 1.8 with dent.


USA spec 75 1.8 with dent.
dent still there even though cannister position changed to beside the battery in 75.


this places the marchart 74 euro spec as very likely built before round about 18/19 november 73.
but there is more.
the european models have owners manuals following exactly the same pattern as USA spec cars that we tracked a couple of years ago.
ie there is a first owners manual dating from August 1973 print which has only 2.0 on the cover. there is a second owners manual dating from October 1973 print which includes 1.8 and there is a third print dating November 1973 print also inclusive of 1.8 on the cover.

I conclude (probably reasonably) that 1.8 euro spec production even though it was not an L jet engine did not commence until the same time as the L jets - end of October/Start of November 1973.

that would place the porsche museum car in a Vin Band covering the first three weeks of Nov 1973. approx 07500 - 09500.

have to get someone to go to the museum and open the trunk and get the Vin number one day to see if my prediction is correct. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)

i think is mileage is probably correct. less than 20,000 km car (12,500 miles).
or at the least its once around the clock but given its kilometers = 120,000km = 70,000 miles. either number is plausible. and still low mileage.
i thought it might have been repainted and restored.
but i am inclined to think its a very low mileage original car.
given the EGR mockup artefact? not meddled with much at all since the 70s.
likely why Dr, Marchart donated it to the collection?

whcih also means its black back pad in the engine bay is probably genuine?
@JeffBowlsby ?
another thing i spotted with the 1.8s.
some seem to have black back pads rather than grey.
i think somewhere in there was an alternative supplier for those pads - a bit like the windscreens. being either sigla or kinonglas depending on date. there were batches of cars supplied with either one brand or the other.






other examples from L jet files of black engine bay back pad similar to porsche museum car. black pads have a kind of ripple surface finish almost like orange peel paint.

11/73 Vin 08482


11/73 Vin 08442


Vin 09271


05/74 Vin 17931


they seem to pop up at start of 1.8 production in nov 73 and appear again towards end later 74.

my 01/74 has the more usual smoother grey engine bay pad as do most examples on file.

?????

[StarBear]

@wonkipop
@jeffbowlsby
Yep, my visor pins are chromed. My 74 1.8 (11/73 chassis, 5/74 completion) has quite a few leftover 73 parts, like seat upholstery; had never though about the pins.

[wonkipop]

@wonkipop
@jeffbowlsby
Yep, my visor pins are chromed. My 74 1.8 (11/73 chassis, 5/74 completion) has quite a few leftover 73 parts, like seat upholstery; had never though about the pins.

thanks buddy. (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif)
does your vin really say 5/74 or is that the date of sale?

anyways looks like they were maybe using chrome pins and changed somewhere between nov 73 and jan 74.
be hard to pin point when. got plenty of examples on file but hardly any have a fluke detail shot of the sun visors naturally. (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif) (IMG:style_emoticons/default/biggrin.gif)