Has anyone recently had there injectors cleaned/calibrated? I've received a quote for $675 (US dollars) to have the injectors set, an induction service (check for and clean carbon) and to have a Vacu-Tech test perform (to look for vacuum leaks).

Not really sure if I need all of this done? When I called the shop I told them the car runs fine but a little hesitant in starting (almost like the car is flooding) and that I was interest in having the injectors cleaned and calibrated. Above is what they came back with. Does anyone have any experience in this area, suggestions, or thoughts.

Thanks

Scott

1966 230SL

Marshall,

First go to this site's Knowledge Base, click on Mechanicals, then Engine, scroll down to the Links section and click on Starting Relays and Valves. You might want to just cruise around in the Knowledge Base looking at anything relevant, there's been a lot of discussion on fuel system and starting system problems.

The Cold Start Valve can fail for several reasons: stuck valve; stuck solenoid; bad solenoid; bad thermo-time switch; bad relay; bad wiring. With luck, it's only the first 2 of these.

First test, jump a hot wire to the CSV solenoid terminal, it should click. If no click, it's stuck or bad. Remove it, clean it, put a dab of WD-40 on the plunger and work it to be sure it's free. Reinstall (or ground the case), jump it again, if still no click, probably bad.

With solenoid off, put a rod down in the solenoid plunger hole and try to move the valve. It should move easily, if it doesn't it's stuck. Disassemble, clean, and if necessary lightly ream out the valve bore with a roll of fine emory cloth soaked in WD-40, just until the valve moves freely. Don't turn the ignition on with the CSV fuel line disconnected.

Reassemble everything, hook a voltmeter to the CSV terminal, and try to start the engine (with engine cold). You should hear the click and see 12 volts for a few seconds while cranking. If it clicked and you see 12 volts, it will hopefully fire right up now, and you're done (for now...insert evil chuckle here ). If not, it's the thermo-time switch, relay or wiring. Write again when you get here...

Scott, My car sat for seven years. We emptied 15 gallons of seven year old gas, I can still smell it after 4 years.
After several weeks of messing with original tank and pump, I decided to bite bullet and but new. Tank $500, pump-$270, sending unit $110.00 the car started and has been running ever since. I did not touch injection or lines other than to adjust idle.
I do run standard injection cleaner through the system about every 5 tanks or so or about once a year and I have also poured a quart of 2 cycle oil with a full tank of gas as recommended by another site.
Unless gas has sat in line for a lenght of time, which I doubt, or seals have failed I would make sure you are getting proper pressure to the injection pump. These things seem indestructible.

Good Luck
Mike C

Oh, here's another question. Has anyone experience any problems from using fuel line / injection cleaners - is there any reason why I shouldn't use it? I'm thinking about using a bottle of Gumout to clean the injectors, not interested in paying over $600.

The more I drive the car and research how the car starts under different temperature conditions, the more I feel my warm starting problem is with one or all - cold start valve, solenoid and time switch.

I've finally located all of these items in the engine compartment but I'm really new at taking care of a vintage car however, I'll willing to learn and try - one of the reasons I bought the car. With that said, can someone please provide me with a step by step process to check each one of these items. I don't just want to start buying EXPENSIVE parts unless I have no other choice.

Thanks

Naj,
Don't sweat it!
I'm learning-as-I-go too.
It sure made me think I must have alot of misconceptions.
Im really no expert.
Bill Rader

Yep, it's port injection.
injector pressures over 200 PSI are what you need and 225 to 240 is really good. Compression pressures are still serviceable down 130 PSI .
Leaking cold start valves are a common problem but they can plug up too and that will really make the car hard to start when cold. Too many things to really point at just one cause for hard starting.
Dan c

Bill,
A apology is in order!
Just got the head off my car and yes! the injectors spray into the inlet port very close to the inlet valve.I suppose this explains why injection timing is 20 degrees ATDC.

Very sorry sir!

Alarm bells did start ringing after my comment as a good compression pressure is over 150psi while I think doc said good injectors sprayed around 125psi
naj

Scott, the cold start valve is on the intake manifold, far right side, has 1 wire and 2 metal pipes attached to it.

The time switch (thermo-time switch) should be screwed into a casting that is attached to the left side of the cylinder head, right above the injection pump. Has two wires attached to it, probably under a rubber boot.

Checking out the entire cold start system is a good idea, and it's not too hard with a decent wiring diagram.

6 brand new injectors should cost around $450. I use an injector cleaning additive once a year or so. Mercedes on their diesels actually recommends doing this (Techron). I'm definitely no expert, but from what I've heard, there's indeed not that much that can be done to rectify injectors that are not cleanable fairly easily.

Will, after doing a search on Mercedes113 I've learned that my problem with warm starting maybe a result of sticking solenoids/time switches. I've been able to locate the Solenoid on the injection pump (item #13 in the owners manual) However, not 100% sure where the time switch (item #17 in manual) and starting valve (#14) are located in the engine compartment. Can anyone provide a little more insight than what has been previously posted and contained in the owner's manual??

It is direct injection and they come out very sooty, as mine did when I removed them as I'm in the middle of a cylinder head job.
Took them to a local injection shop and he did them for me while I waited. Soaked them in some acid solution for a while and they came out reasonably clean. Cleaned off the rust etc. around the hex head with a wire brush and pressure tested. Charge - 10 pounds or about 15 dollars. They look totally sealed and therefore unrepairable.
naj

Also I don't think carbon would be an issue.The injectors are mounted in the intake ports in the head not in the combustion chamber.(indirect injection vs direct injection)

hehehehe
You can almost buy new ones for that much.
To my knowledge , you can't calibrate fuel injectors. You can test them and then match the pressure within a set, but that's about it. Never heard of this vacuum test but I'm not a fuel injection expert.
Usual cost to clean a set of 6 injectors is less than $ 100.00 in most cases.
These guys seem a bit......exspensive?
Dan c