KE Jetronic EHA Adjustment

I discovered at the MBCNSW Dyno day that my 560SEC was running dangerously lean.   Lean enough to cause damage to the engine.  While I was in the USA for work, I went to the Mid Florida Auto show.  I met Pierre Hedary there (who runs an independent Mercedes workshop), who suggested that I should start by testing my fuel pressures and that he had a couple of videos on youtube to help.   The first video was on checking KE Jetronic Fuel Pressures.  The second video was on KE Jetronic EHA adjustment.

As I own two KE Jetronic cars and one K Jetronic, It made sense to purchase some fuel pressure gauges.   They were about $100 USD.  The test gauges plug in to the fuel distributor in two places.   The first plug (without the valve) goes into the test port on the side of the fuel distributor.   The second plug goes into the outlet for the cold start valve.     The gauge set comes with the right fittings to rig it up.

KE Jetronic fuel pressure gauges

Immediately I was able to rule out the fuel pumps and fuel pressure regulator as my starting fuel pressure was good.   The test calls for two readings.   the first one is from the test port and the valve closed.    The second is with the valve open to the cold start fitting.   The ideal readings are 6.0 bar with the valve closed and 6.4 bar with the valve open.   What is more important than the actual values is the 0.4 bar difference.

KE Jetronic EHA Adjustment

As can be seen from the picture above, I had an 0.3 bar difference.   This meant the car was too lean – which is what I had observed on the dyno.   Most KE Jetronic cars have an oxygen sensor that controls the operation of the electro-hydraulic actuator (EHA).  The 560 ECE does not have an oxygen sensor.  In this case, the EHA can be adjusted manually.   It is the small back control unit on the right hand side of engine.

KE Jetronic EHA adjustment

Once removed, the slotted screw is removed to allow for adjustment.  A small allen key is then used to adjust the EHA.  In my case, I adjusted it in about one third of a turn.  The EHA is then replaced, carefully to avoid disturbing the o-rings.

With the EHA adjusted and re-fitted, I re-ran the test.  This time, I saw 5.9 bar on the test port with a bit over 6.3 valve open.  Success! I now have the pressures in specification.  I’m happy to leave that bit extra over 6.3 – I would rather be ever so slightly rich than too lean.

560SEC after EHA Adjust

These test were all done at idle.  Next thing was to check the pressures at some higher RPM levels.   I asked a neighbor to hold the car at 1,000, then 2,000 RPM.  The fuel pressures stayed steady at these increased revs.

KE Jetronic EHA adjustmentI also ran another test from a member of BenzWorld.   Holding the revs at 2,000, I pressed on the air flow meter plate.  This tricks the car into adding more fuel.  If the engine is lean, the revs will increase, but if it is not, the car will bog down from getting too much fuel.   In my case, the car bogged down.  This was another sign the pressures were at the right level.

The final test was to check the readings of the potentiometer for the air flow meter.  This is on the other side to the EHA.  Correct spec is 0.7 volts at idle between pins 2-3.   My car was at 0.9, so very close even if not perfect.  The voltage also increased as I pushed down on the air flow meter pressure plate.

Potentiometer

After these tests, all evidence points to having fixed the lean running condition of my car.  I don’t have a dyno to test it on, but the car is now adjusted back to the correct specification.    I found the KE Jetronic EHA adjustment to be fairly straightfoward, with the pressure gauges.

2019 Mid Florida Auto Show

A couple of weeks ago, while I was in the USA I attended the Mid Florida Auto Show and Lake Mirror Concours.     This posting is a few weeks old, as I didn’t have the cable for my camera to transfer the photos.   I was in Orlando for work, and Lakeland is about an hour or two away.    The Mid Florida Auto show is normally a picturesque event set on the shores of Lake Mirror.   This year, Tropical Storm Nestor hit North Florida.  While Nestor was a fair way away, it was close enough to cause torrential rain in the Central Florida area.     The rain meant the show was moved to a set of multi-story parking lots.   It also drastically reduced turn out.

While I at the show I met Pierre Hedary, who runs a YouTube channel on Classic Mercedes.    If you have not seen his channel, I suggest you check it out.   Pierre runs an independent Mercedes-Benz workshop in the Central Florida area.   He focuses on Classic Mercedes such as the Adenauer,  Fintail Era (110, 111, 112, 113, 108, 109), Compacts (W114/W115), and the cars of the 70s and 80s.  (116, 107, 126, 123, 124 etc).   He is especially known for his expertise on the more esoteric Mercedes designs such as the M189 engine.

Pierre invited me for a tour of his workshop and collection of interesting Mercedes-Benz models.   He also gave me some tips to tune my lean running 560SEC.    At his workshop was a plethora of 111s, 108s, 109s and 113 SLs.  He also had some really interesting models in his own collection such as a W108 280SE 4.5, a W109 300SEL M189 etc.   In some ways his workshop reminded me a bit of MB Spares and Service in Canberra.    Both specialize in similar models and have the same sort of cars at their workshops at any given time.

The highlights of the Mid Florida Auto show was seeing the 300S, which belonged to a local Attorney and Nicolae Ceaușescu’s Rolls Royce Phantom V.   The Phantom and its competitor, the Mercedes-Benz 600 seemed to all too regularly end up as the conveyance of bloodthirsty dictators.     It was also fun to see some Amphicars frolicking in Lake Mirror, as the weather had cleared up by the afternoon.

Despite the weather it was an enjoyable day.   I would like to visit again to see the show as intended.

2019 ACT Marques in the park

This weekend I planned to drive down to Canberra for the MB Spares and Service clearance sale.   Originally I was going to do a Saturday day trip, but I noticed that the Marques in the park show was running the next day.   From what I read this is a fairly large, but still informal show, with normally a few hundred cars in attendance.

I decided to make a weekend of it – stay down Saturday evening and then attend the show Sunday morning.   It worked out quite well – I attended the show from 9Am to 11:30 and then headed back to Sydney.    I stayed in the same hotel as the ACT German Car show.   The Woden hotel that offers reasonable prices and loads of secure undercover parking.   The show itself is held in a park in Belconnen near a lake.  A great spot and easy to get to.

The show was quite good – everything from a rare Bentley Continental (the real one, not the VW) to pre-war Packards to a beat up old Camry.    Some of the highlights for me were:

  • The 50’s Ford Convertible with the folding metal roof – 40 years before the SLK.   I saw a similar car the Concours D’Elegance of America.  Given how rare these cars are, it is great to see one in Australia.
  • A Chrysler 300H.  I prefer the rear end of the G, the H is still a very impressive automobile and the dashboard is almost out of the Jetsons.
  • The Pre-war Packards.   The 1927 model even had a spot to carry your motorcycle!
  • A lovely red Austin 3 Litre.  These cars are rarely seen in Australia.
  • A black Corvair Coupe.  The Coupe has such elegant lines.  One of the most innovative cars to come out of the United States in the post war era.
  • Seeing a 220SE Cabriolet parked next to its contemporary – a 230SL.
  • Getting a tour of all the clever touches of a 1967 VW Microbus camper.

If you’re in Canberra,  the Marques in the park show is well worth stopping by.   I’m glad I went and checked it out.   If I go again, I will drive my car into the display field.   This show is rather informal, you don’t need to be a club member to participate.    I like these informal shows.

MB Spares and Service Clearance Sale

Today I traveled down to Canberra for the MB Spares and Service used parts clearance sale.   I managed to score a few bargains that will hopefully come in handy in years to come.

MB Spares and Service closed down the spares side of their business a couple of years back to focus on the service and restoration.    The spares business catered for both new and used parts.    So they can consolidate down into one building, excess used stock was on sale today.   Having a stock of good used parts is quite useful for a restoration and service business.  The point of the sale was not to liquidate the entire stock of used parts, but bring it down to a level that made sense.

MB Spares and Service

I didn’t have urgent needs, but keeping these classic cars on the road can be quite expensive.  I’ve found its generally a good idea to buy commonly used parts cheaply when they are available.     It is difficult to predict what you might need in the future, so easy to get quite silly during these sales.   I focused on things that would not make sense from insurance.   For example, even though they had some good rust free C107 doors, if my car is hit and needs a new door, I will get this from insurance.    If on the other hand I crack a front headlight, having a spare one is better than $800 excess.

MB Spares and Service

Considering the effort to dismantle the cars and store the parts, the prices were very reasonable.   I am surprised more people from Sydney didn’t make the trio down given the wide range of inventory.     There was so much there it was even tempting to look at parts for models I would be interested to own in the future!  In the end pragmatism ruled and I ended up with some things that I should be able to use easily, and are not too difficult to store.

Parts

Some of what can be seen in the boot of my 300SE includes a W126 front grille, a W126 alloy wheel, a 300SE radiator, a W126 front headlight, set of W111/W108 headlights, a window regulator for the 300SE and a mirror motor for the 560SEC.

The most pressing repair is the front left window regulator on my 300SE.   The good used unit I picked up should be great here.

This was also the first time I have taken a road trip in the 300SE.    Generally I am either displaying the 250SE in a show, or find the 450SLC or 560SEC beter road trip cars.   The 300SE was a better choice for this trip, as the MB tex interior is less likely to be damaged if I was carrying something inside the car (wrapped up of course).   Also, the 450SLC does not have rear brake calipers at the moment, and the 560SEC is still running lean.

The 300SE performed well on the trip.   I discovered that it has a minor vibration from the front suspension at freeway speeds.   The cruise control does not work either.   I’m not too concerned about cruise control as I don’t really use it much.  I will need to inspect the suspension.

300SE

While I was at MB Spares and service, I saw two barn find cars they are working on.   The first is a beautiful W108 250SE.   I understand it was taken off the road in the 1980s and it really is a time warp.   Normally I am not a fan of white cars, but it looked very smart in white with red MB-Tex interior.   They also had a unicorn in the shop, an Australian delivered 300TD W123 with a factory manual transmission.    My preference is the 250SE, but the 300TD is a really interesting car as well.

All in all it was good day – a road trip, some bargains and a poke around an Aladdin’s cave of Mercedes parts!

2019 Linnwood House Car Show

Today I attended the Linnwood house car show.   In prior years, this was focused around the Rolls Royce display, but this year it was more of a general car show.   I like this car show as it is informal, no marshals, security guards or crowds.   Just rock up with your car and park in the vast grounds outside the historic house.

This year the main displays were from Rover, Wolseley, Austin and various classic American marques.  The car of the day for me was a lovely 1937 Packard Super 8. These cars are hugely impressive in the flesh – pictures never do them justice.   There were a few other very nice classic American cars like a Chrysler Windsor and a lovely 50’s Cadillac convertible.

I was also keen to see the Rover display as I am a fan of the P5 model in particular.   There was a good selection of earlier cars, P4s, P6s and even SD1s, but only two P5s on the day.  That was a shame as in prior years there have been a great variety of models to choose from.

I drove there in the DS.  I didn’t display the car as I was not a member of any of the clubs participating, but I don’t think that would have mattered.   I hope in future years even more car clubs attend the Linnwood house day.   There is loads of room and its a very nice car show.

Citroen DS electric cooling fan

The Citroen DS cooling system is somewhat unique in that it relies almost exclusively on pulling air through ducting to cool the radiator.   Most cars have a grille where the faster the car moves, the more air is pushed over the radiator.   On modern cars this is the grille below the bumper.  It is only at idle they only rely on pulling air through the radiator.  The Citroen DS has a large plastic fan attached to the camshaft pulley.  That fan sits behind the radiator and then pulls air through based on engine speed.   The DS21ie and all DS 23 models augment this with an electric fan and an improved radiator / header tank.   The Citroen DS electric cooling fan is mounted alongside the mechanical fan (actually almost inside it) and also pulls air through the radiator.

My car, being a carburetor DS21 does not have this improved radiator / electric fan combination.    The Citroen DS cooling system worked quite well when the cars were new.  However, a combination of the hot Australian climate and an almost 50 year old car that spent quite a lot of time in South Australia means that my cooling system struggles in stop and go traffic.   For international readers, South Australia has very hard water resulting in mineral deposits if distilled water is not used.

While I was having some other work done, I had a Davies, Craig fan fitted behind the radiator.  This is to augment, not replace the mechanical fan.   The setup is basically the same as the Citroen DS electric cooling fan.   Over the years people have tried to replace the mechanical fan entirely. This is a recipe for disaster as the electric fans cannot pull enough air at high speed with no ram effect.     The Davies, Craig fan is equipped with a controller that allows adjustment of the cut in point.

Citroen DS electric cooling fan

I also wanted to know when the fan is running.   The Citroen DS instrument cluster has an extra warning light that is not used in my car.   This is for parking lights.   The spot for this warning light was taped up.   I have a spare instrument cluster for parts, so I was able to grab another bulb housing to enable this extra light.

Citroen DS Instrument Cluster

Looking at the parts instrument cluster the tape used to disable the warning lights not in use from the factor can be seen.   This is at the 12 and 6 O’Clock positions.   From there, it is relatively easy to run another wire to the back of the instrument cluster for the warning light.   The speedometer cable is already running right past this area.    The connections on the back of the cluster are well documented.

Citroen DS electric cooling fan indicator light

I would have preferred a green or orange warning light, but the red one is fine.    It works quite well.   I took the car for a drive in the 30 degree heat and the light was on for quite a lot of the time, but it did cycle on and off as the fan kicks in/out.   The fan is wired to be ‘always on’.   This means that after the car is turned off, the fan will continue to run if the engine is hot enough to warrant it.  I did this because heat soak can be an issue in these cars.   On my test drive, it ran for about 10 minutes after I switched off the car.   The risk is draining the battery, but on a hot day this is a useful feature for a short stop.

Citroen DS electric cooling fan indicator light

I don’t want my cars to be garage queens.  This modification, while not factory should make the car more usable in Summer.

Citroen DS Window rubbers and felts

After my Citroen DS was painted, there were a couple of cosmetic things wrong with the car that were far more noticeable.   One of them was the DS window rubbers and felts.    The previous owner had used generic units, and they didn’t fit all that well.   Proper reproduction units are available, which are the right size and use the standard mounting points.

I didn’t get a chance to take before and and after photos, but the new DS window rubbers and felts look much better.

DS window rubbers

As well as the proper window rubbers and felts, the correct mounting hardware is also required.

DS window rubbers and felts

This isn’t a job I tackled myself, as I wasn’t sure how it was done.    I did learn a bit more about the history of my car.   The window hardware, and maybe the doors are not original to this car.   Fairly early in the production run, the window mechanism was modified to push the top of the window harder against the seal when it is closed.   This modification was done due to sealing and wind noise complaints.   My car does not have this.   I know I have a DS19 boot lid, and an ID19 roof, so when the car was fixed up in the 90s, it would seem that a fair number of DS19/ID19 parts were used.     The car also used to have DS19 window winders, which I have since replaced.

DS window rubbers

In the picture above, the mounting hardware can just be seen.   It actually worked out quite well I did this job, as the adhesive I used for the plasic moisture panels had already started to come off.   This time, I used the same adhesive as I had used for the Mercedes W126 under bonnet insulation.

The car is almost ‘finished’.  I am waiting on one more piece of chrome trim around the roof I am replacing.  I also need to re-fit the boot badges that I removed to have the paint polished on the boot lid.

Speedometer Ratio Box

I changed the differential ratio of my E-Type about two years ago.    My car was first delivered in the USA, so it came standard with  3.54 ratio.    Most of the 4.2 cars were standard with 3.07.    When the car was restored in the 90’s, it was converted to 3.07.   However, the previous owner converted it back to 3.54.   My conversion put it to 3.07 again.    The car still has its original speedometer, which means both the speed and odometer were incorrect.   This page lists the different Jaguar E-Type differential ratios.

There are generally two ways of accounting for the differential ratio in the speedometer.   American cars have an easily changeable speedometer gear in the output of the transmission.   This allows them to have the same speedometer regardless of the differential ratio.   This approach simplifies things for their high production volumes.   It also simplifies modifications, although I doubt this is the aim.    European cars generally had a different speedometer for each ratio.      If the ratio is changed, then either the speedometer needs to be changed, or an inline Speedometer ratio box needs to be installed.

Speedometer ratio box

As Sydney is infested with speed cameras, I had the cable removed from the car and sent to a speedometer shop.    The original plan was to modify my cable to accept a ratio box.   However, my cable wasn’t able to be modified – it was too thick and the right fittings are no longer made for such a thick cable.    Therefore, a new cable and ratio box was made up.    Having the new cable made up was more expensive than I was hoping, but If I avoid two low range speeding tickets, I am ahead.

Helpfully, the Smiths speedometer actually lists how many revolutions per mile it expects.   In the case of an E-Type with a 3.54 ratio, this is 1312.    For a 3.07 ratio, it is 1120.   These ratios allowed the speedometer shop to correctly build the speedometer ratio box.    For reference, the 3.31 ratio should be 1216 revolutions per mile, and 2.88 is 1058.

The new cable was installed today and a small bracket fabricated to hold the speedometer ratio box.

Speedometer ratio box

I have not yet compared the speedometer and odometer to a GPS, but it was reasonably accurate before the differential ratio change, so I expect it to be ok.   This is a timely change as the NSW Government have just announced the speed camera warning signs are to be removed.

Yet another way of attaching NSW Historic Plates

After using blank plates as a way of attaching NSW Historic Plates on the 450SLC and the 560SEC, the adapter I fabricated for the 250SE was looking rather shoddy.   I made it myself out of aluminium.   I used thin aluminium to make it easier to cut.   The thin aluminium bent easily and now had creases.

I liked how using the blank German plate filled in the spot for the plate rather well.   This plate is far too modern for the 250SE.   That style of plate was introduced in the early 90s.  It is quite contemporary for a late 80s car, but doesn’t fit so well for a mid 60s model.   Blank plates are also available for the older style German plates, which were white with a black boundary.    This is also the style that Swiss plates used at the time.   I have a photo of my car in Switzerland when it is new, on Diplomatic plates.   It would be great to find the square ‘CD’ tag one day to attach!

attaching NSW Historic Plates

I also used the last of my older style MBCSW badges.  I’ve ordered a couple of new ones as well.    Like with the other blank plate I bought, it was just a matter of drilling the holes in the right spots.   As this is the same size as the original plates, it fits very well in the bumper indent.   The factory plastic mounting wedges are pushing the plate out a bit too much, so I may replace them with something flatter.   They are invisible once the plate is mounted anyway.

At some point I will probably mount a badge on the right hand side.   I’ll be keeping an eye on eBay for something interesting.

Coomparison old vs new

As a comparison, I am much happier with the result than my previous attempt.  I also used screws instead of pop rivets, which will make removing the plate to add the second badge much easier.   I used a dremel to cut off the excess length on the back of the screws.   The links to my other cars above will outline the other ways I have been attaching NSW historic plates.

450SLC Dragging rear brakes – part 1

For the last couple of years I have noticed a noise from the rear of the 450SLC while driving.   At first I thought it might be a wheel bearing or some kind of bushing.   I mentioned it to my mechanic and he took and look and it wasn’t any of those things.

Last time I took the car on a longer drive, the noise was getting worse, and I noticed after I returned the rear wheels were hot to the touch.   Too hot to touch.    I realized that my noise had been dragging rear brakes all along.

Both sides were hot the touch, so it wasn’t just one bad caliper.    I went back and checked my maintenance records for the car and saw that the brake hoses were last changed in 2003 when I purchased the car, and one of the hoses changed again about two years after that.  16 years is about all the life that can be expected form these hoses, so I decided to replace them.   I also thought it would make sense to replace the master cylinder, as it is more likely to be causing dragging rear brakes on both sides.     Unlike when I had a similar problem with the Jag, the brakes were not locked hard on, just dragging.

Today, I did some further inspections.   I removed the rear wheels and looked at the condition of the calipers, pads and rotors.

Dragging rear brakes - calipers, pads and rotors

The rotors were still within the spec from the workshop manual.   The hoses looked old, and not particularly flexible.   It was also quite hard to push in one of the pistons to remove the pads, even with caliper disconnected from the brake system.     This led me to remove the caliper for further inspection.

It was the same story on the other side.   Removal of the calipers showed that the heat had made the seal rather crispy.

Rear calipers

These calipers can be rebuilt.  I may just replace them as the pistons don’t look great and the heat may have done other damage.   I am not sure if it is to do with the heat, or the 16 years on the car, but I found it almost impossible to remove the flexible hoses.  Even using the flare nut wrenches I managed to damage one of my hard lines.   I have liberally soaked the other side in penetrant to see if that will help when I get the new calipers.

While I was at it, I also replaced the master cylinder.    The brake fluid looked pretty good from a visual inspection.   I was quite surprised how much vile black fluid there was in the rear chamber of the reservoir once I removed it.   This is even after a flush about 18-24 months ago.

Dragging rear brakes - changing master

Some stained old shirts helped me protect the paintwork from the brake fluid.   In contrast with the flexible hoses in the rear, the lines were easy to remove from the master.   The coolant expansion tank needs to be unscrewed to get the master out. It does not have to move very far, so it does not need to be emptied.

new masterNext steps are to remove and replace the hoses from the rear, fit new calipers to the rear and replace the front hoses while I am at it.   At this point I do not have any indication that the front calipers need to be replaced or rebuilt.