Introducing me and Laurie - and a few queries..

[GWD]

Hi
My name is Greg and I live in Sydney, Australia. After reading these forums for quite some time, I've finally become a member. This is a great resource! Your posts have guided me through some work on my Mercedes "Laurie"- which is a 1968 280SE which I bought off an elderly widow about 18months ago - her husband had owned the car since 1972 and had spared no expense in maintaining it over the time so I scored a very nice original example - RHD, black with cream mb tex.

So far I've refinished the walnut which has come up a treat, but took a long time to get the right result - i'll restate everyone elses main points here - BE PATIENT, and DON'T USE SANDPAPER.

My aim with this car is to restore it to original condition (it's not far off now) and make some improvements to performance and fuel economy. It could become my daily driver once again provided I can resolve a few issues which I'll be posting questions for soon.

For the moment, my big problem is that I've had the car off the road for a year and garaged/covered. It was being started regularly and driven short trips until about 3 months ago - returning to the car, I'm now finding the engine cranks but will not start - I have spark but no start - will try again later today with a fresh strong battery and some "start ya bastard" which is an ether based starting spray.. any advice would be appreciated.. I am prepared to throw some money at this car to make it as good as can be but want to make sure I'm spending money on the right things..

Mechanical problems:
Brake booster appears to leak air - vacuum noise evident on pedal depression. Brake fluid appears to leak from master cylinder. My mechanic has suggested that this could be causing my starting problems due to vacuum system connections - any pointers here guys?? Should i replace with second hand parts, new parts or can these be reconditioned?

Heater and Aircon - both have been disconnected - heater core is bypassed with heater hose - heater levers are stiff to move, and attempts to flush the heater core make me think it's blocked... any tips here - NO ONE I HAVE FOUND WILL TOUCH THE HEATER ON THESE THINGS!!..
Aircon has also been disconnected. I do have the york compressor and all hoses etc and the condensor is still attached to the car - is this a hard thing to refit/regas or would i be better to install a newer compressor as mentioned in some recent posts on this board?

Performance/Economy mods..
I understand that an ignition upgrade would be a good idea - who makes the best setup for this - i've heard pertronix/crane..

fuel.. I use premium unleaded RON95 and have been told many times over that it's fine but am concerned that the engine won't like it. Should I use the LRP available here or up it to 98RON premium. My other option is a conversion to LPG which may be cost effective in the long run.

Sorry for such a longwinded first post. Any assistance or referrals to posts I've missed would be great. I'll keep trawling the boards here for answers, but any pointers would be great.

I'll post some pictures of my car soon - you EURO light fans should be impressed.

Thanks for reading

[300SDog]

On the Heater problem:

Its gotta be mid-winter downunder....... nevermind the levers, but how are valves at engine compartment firewall?? There are two directly controlled by cable levers on the dashboard. These valves can jamb and leak - better address them from engine compartment instead of risking brakeage of fragile dashboard heat control nibs. Hell, you can set them from behing the firewall for the season, then forget about them. Also gotta flush, flush, flush the cooling system and heater core..... something MB recommends twice each year that garages hate to do - because the process trashes their shop.

If the system has been bypassed, we've gotta see pics to sort out the hoses. One generally runs from right side of engine to valve system, then from valve system to cyl head on left side.

On the crank/no-start problem:

If the spark is Orange not Blue at disconnected sparkplug line, then the coil/ign system is weak. Hell yes, buy the electronic upgrade and somebody will talk you through the installation. Otherwise gotta suspect fuel filter, fuel pump blockage on the SE fuelie. Basically, itsa car that MUST be driven. My advice is blowout the tank with fresh fuel at long distance high speed run.

The less these cars are driven, the more problems they will have. Losers get hammered owning and constantly bringing them out of storage. Widow's husband probably got screwed at professionally maintaining the car while driving maybe 9,000 miles per year..... meanwhile savvy DIY'er can rack up many more miles in daily use with merely vigilant maintanence and zero major repairs. Most of them die from decay, rarely from being driven to death.

[230/8]

Regarding your heater problem, it would be wise to assume the bypass arrangement was done for a specific reason. And, the most likely reason is a leaking heater core. So be prepared that it may leak once you have O'hauled the valve and properly reconnected the hoses. Core replacement is not an easy or pleasant job. As to the valve, simply remove it from the firewall and disassemble. Small snap rings hold the cores inside the casting, and they are sealed with special O rings which cost an arm and leg last time I bought them. Simple O rings from the parts house should work once you carefully clean the innards of the casting and the valve cores. I used regular O rings but had to stack two as I recall. The special rings have a sealing taper to prevent leaks. Mine have not leaked in 20+ years, so I never used those special parts, keeping them just in case...

Regarding the start problem...too many things can cause this to deal with it over long distance. Remember the basics: An IC engine needs three things to run 1) fuel in the proper proportion to air; 2) compression to a reasonable level; 3) ignition (Spark) at the right time in the rotation cycle. If you have these right, then she'll run.

Pertronix is great for ignition, it is the single best thing I have ever installed on my other old cars (Mustangs), but verify that Pertronix have the right unit for your Bosch distributor number. Bosch made MANY variations, each with a different number and using various combos of parts from the bin. Unless you plan to use the car a lot, you may find the original point set up to be just fine so long as it is in sound condition. My maintenance book lists this as a C service item. Setting point gaps and timing are pleasant tasks for most DIYers who enjoy their cars... for some of us it's a mental health aide to combat the stress of the day. Personal choice here...

Good luck and let us know how your work progresses. Oh, FYI, do you have access to Mercedes Benz Classic magazine? A very good glossy publication for those of us who admire the old timers. Check it out if you can.

230/8

[Russ114]

on the fuel issue, i run LRP on my M110, only because of the differences in valve stems/guides and seals on pre 84 Mercedes Engines.

Pertronix is the way to go for ignition, they have an advertisement in Unique Cars nearly every month.

why do you need a heater anyway? my valve is bypassed. and on a cold night the warmth of the engine seeps through the firewall and keeps me warm!

[GWD]

Thanks for all of your responses guys! Sorry for not posting again sooner - I've been rather busy with a new job. I appreciate the detail you've gone to

I've not been able to start the car yet - I have a strong blue spark, and i'm getting fuel and have clean filters...now i'm worried about compression - but although i understand how the engine works i'm not technically confident enough to go poking about or drawing conclusions and it's hard for you guys to diagnose being so remote, so I'm going to wheel in the old retired mechanic that serviced it for 20 years after speaking to the old widow about it.. more on that as news arrives..and i'll look into the pertronix once it's going again too -

Russ114 it looks like i'll be switching back to LRP from Ultimate - thanks - I know i shouldn't need a heater but sydney is a lot cooler in the winter than brisbane and it's nice to have everything working as it should.


230/8 & 240DieselDog
thanks for the advice on the heater - i'll look into it over the weekend and see how it goes - i've pulled the whole dash to bits and put it back together again fine for the refinishing, so i'm not scared of spending some more hours on getting this thing to heat again! Cheers!

Thanks guys, I'll be posting more often - any other advice of note would gratefully received!

GD

[GWD]

one of my heater cables was snapped at the valve.
This makes me think that maybe the heater valve is stuck in the on position? being always on that it was too hot to drive around with down here in summer so they bypassed the heater or that the problem could be the heater core is leaking and thats why they bypassed it.
from what i can see that valve is stuck pretty good. can i take it out without removing the ac surround and heater box or is this thing in the core??


I've had no joy starting my car yet javascript:smilie('')
frown
I haven't had a chance to get the mechanic in to work on starting - that will happen in the next few weeks - the car is not registered, so once started i can't just drive it on the road to give it an "italian tune" as everyone suggests - so i'm going to have to get it sorted then registered and insured and just start driving it again!! this project can take a little more time if need be while I get everything else back to scratch - once on the road I don't want to have to pull it off again for anything for a long while.. will post pics in the next week or so

GD

[psfred]

Greg:

DO NOT, under any circumstances, mess about with the fuel injection linkages or pump without a manual and great care -- it's possible to seriously damage the pump by attempting to adjust mixture while running, and if you get the linkages messed up, it will be impossible to get it to run right. Non metered airflow mechanical injection after all!

Your problem is very likely seriously crudded up fuel. Drain the tank and put in about 6 gal of fresh fuel. Add a bottle of injector cleaner (the good stuff, RedLine, may not be available in Down Under, but I'm pretty sure Shell Techron is). Jumper the fuel pump relay and let it run a couple of hours before attempting to start. This will often loosen up the slime in the injection pump and get the fuel rack moving again. It may help to remove the injection lines at the pump and crank the engine with the gas pedal to the floor to flush the plungers, too.

If you can then get it to run, keep adding some cleaner to each tank of fuel to clear the slime from old fuel residue -- when the volatile part evaporates, you will be left with some thick, slimy stuff mostly comprised of detergents and additives that isn't ignitable. This will stink to high heaven and foul the plugs, etc.

Mostly likely, alas, you have a stuck cold start valve and a stuck fuel control rack. The latter can require an injection pump overhaul to free it up. Hopefully, it's only dead, unburnable fuel.

For the heater, the valves are stuck. Remove them (instructions on this site, do a search) and clean them, then re-attach the heater hoses properly and do a citiric acid flush.

Peter

[GWD]

Thanks Peter.

I drained the fuel and will top up with some fresh LRP and injector cleaner (we do have techron but I've not seen redline) this weekend and see if I can get her kicking over again..

where is the cold start valve?? On top of my inlet manifold and hooked into the fuel injection linkages is a mechanical/electrical contact with two wires coming out of the top that have been cut but seem to attach back to this little doohicky.. Is this my cold start valve?? Why would these two little wires be standing in space??

I know a pic would help.. but alas no digicam..

On the heater front, I'll search the boards and try and sort the heater valve and flush the core on the weekend.. it looks like the PO was getting through the little problems like this before he passed away - the box of spares the widow gave me included some cables for the heater control !

>> I'll post more as things progress!

[psfred]

That is the cold start device. It's wired either to a set of switches and a relay from the ignition switch OR through the cold start solenoid on the back of the injection pump, depending on application.

Chances are the electrics failed, and it stuck open, so a bad mechanic cut the wires to prevent over-rich running.

Peter