Fuel In Air Filter / Throttle Body

[RonnieStiggs]

Hi all, long time lurker, first time poster.

I've been working on getting my 1966 230sl Automatic moving after sitting in storage for about a decade. Today I had some success, I thought, but ran into a new and interesting issue I've never seen before. The complete situation is as follows:

• I replaced the fuel pump with a clean rebuilt model from Vintage Euro Parts (mine was non-functional and too rusted to get apart without damage)
• I replaced the fuel pump with a clean rebuilt model from Vintage Euro Parts, appears to run great
• Replaced fuel filter as a matter of corse
• Confirmed that fuel flowed through the pump and reached the filter when key was inserted
• After a few tries of about 15 seconds  the car started, had a low idle for a few minutes but eventually leveled out
• I let it idle for several minutes, baked out and drove back into my garage (basically just a function test that everything was working)
• Turned it off and let it sit for an hour or so so far all seems good
• Turned the car back on to move it over to my lift, same start up story. took a few tries, had to crank it for a while but eventually started, and had to run for a minute or so to
• When I put my foot on the break to change gears it died, figured it might be idling too low, break booster engaged and took too much power for it to keep going, no worries I'd just feather a little bit of gas next time
• Car cranked again, but wouldn't start back up after several attempts
• Had to call it quits for the night, but while cleaning up I noticed a leak coming from near the front passenger wheel well
• Further investigation showed that the leak smelled like gasoline and was coming from around the air intake filter
• After removing the filter I discovered that it was damp, smelled of gasoline, gasoline was pooled in the intake housing and was dripping from the throttle body

I've been trying to investigate what would have caused this. As I'm more familiar with newer cars, (w123, w124, and other cars from the mid 90s to present) I may be missing something completely obvious to ya'll, but so far I'm at a loss.

Has anyone run into this issue before, or know what could cause this?

[Lorsar]

Check the gaskets on the cold start valve. In my case I could see the fuel squirting out the side of it.

[RonnieStiggs]

I don't believe any fuel was squirting outside of the air filter / throttle body housing, but this definitely gives me a starting point, thank you!

[RonnieStiggs]

Apologies for the double post, as I just thought of this, Is it possible that me, over-cranking the car when it wasn't starting caused this?

[ja17]

Not likely but possibly. It does sound like a mal-functioning starting valve. Make sure your ignition spark is good.

[stickandrudderman]

Remove the small 8mm (or is it 7, I can't remember) plug just under the cold start injector and confirm that you have not got a constant supply of fuel there when cranking or running.
If you have then search here for cold start injector details.

[RonnieStiggs]

Thanks for the assistance everyone!

I removed the 5mm bolt from the CSV and, after turning the key into the on position (not cranking) fuel was jetting out of the hole like fountain. Definitely the issue here. Is there a specific seal or gasket that is the general cause of this issue? or should I be sourcing a replacement CSV? So far from what I've read the answer is "rebuild CSV" which leads me to believe its more complicated than a gasket or seal.

[Pawel66]

I think all you need to know is here: https://www.sl113.org/wiki/Engine/ColdStartValve

Become a Full Member - it really pays out.

[Lorsar]

Authentic classics sells this kit. 

https://www.authenticclassics.com/Mercedes-Cold-Start-Solenoid-Hardware-Seal-kit-p/auth-003542.htm

Worth a try to soak the jets in carb cleaner and replace the 2 o rings.

New one is over $1000

[ja17]

The cone valve is probably stuck open. Take it apart and clean it. Remove the fuel line, it is built in the fitting at the fuel line. don't loose the small spring when your taking it apart.

[RonnieStiggs]

The cone valve is probably stuck open. Take it apart and clean it. Remove the fuel line, it is built in the fitting at the fuel line. don't loose the small spring when your taking it apart.

That was exactly it, Removed it, disassembled and cleaned it, works like a charm after re-installing. Started up, idles great, and the CSV seems to be operating as expected

...

Then spark plug 3 shot out of the car, so now I'm dealing with figuring out how to convince a shop to install a Time-Sert for me, or work up the courage to do it myself, but thats likely a story for a new forum thread.

[ja17]

KD makes a nice one step tool which cuts new threads in one step. Used it many times. Be sure to use ample amounts of grease on the tool to collect aluminum shavings as you cut threads. Afterwards crank the engine over with the spark plug out, to expel any aluminum in the cylinders. The metal shavings are just soft aluminum and should not cause any damage anyway. Be sure to flush clean the threads in the head before inserting the new thread insert. Also be sure to use the 3/4" insert and locktite it into place so that it stays place the next time the spark plug is removed.
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=KD+spark+plug+re-threading+tool&_sacat=0

[RonnieStiggs]

Thanks for the confidence boost if it winds up no shops around me are willing to cut/install a new insert for me!

I was locked in on using a Time Sert kit (https://time-serts.com/store/4412e-111/ I believe is the correct one for a w113) due to a recommendation from an old post with a similar issue. Other than the vast difference in cost is the reason why you would recommend the KD kit over the Time Sert? (the overall process looks fairly different and less involved on the KD).

I'm as apprehensive as I am because I'm worried, with my inexperience with this repair, I'll tap in at an angle and effectively ruin the head, I'm not sure if this is more likely with one method over another.

[ja17]

Yes, it looks like that time-serts tool is even better. The "Time-Serts" tool is easier to get centered and started into the head correctly. They both use the same type inserts. Also the "Time-Serts" tool has the  slick seat cutter to help the spark plug seal. Thanks! Also make sure the piston is down in the cylinder before you begin, so that the threading tools do not run into it.

[stickandrudderman]

I always use Time Serts; they're an excellent product.
Drilling out the old thread does need to be done with car so as not to go in at an angle but it's not as difficult as you might think.

[RonnieStiggs]

Thanks for the assistance everyone! I called a couple more shops around just for peace of mind but still no luck with anyone willing to do the job, so I'm going to get a Time Sert kit and have at it myself.

As I'm not fully aware of the cars maintenance history it is possible that the thread was repaired in the past, as recently as a week ago there was a picture in the forum of a helicoil repair that stripped in a similar fashion to mine, but it seems that the image has been taken down. I don't think I can see anything off in my thread, but I'm not positive of what I'm looking for.

Here is the offending Spark-Plug-Way on my engine.


Are there signs of previous repair here? And if there are, what are they so I know what to look for in the future.

Thanks again!

(Edited for clarity.)

[ja17]

If it has a heli-coil insert already in place, it will have to be removed first.

[RonnieStiggs]

If it has a heli-coil insert already in place, it will have to be removed first.

What are the signs of an insert already being in place? Do the threads look obviously different, or anything like that? I'm just unsure of what to look for.

[stickandrudderman]

A helicoil is like a spring. If it has one inserted you'll be able to get a fine pick behind it and hook it out.

[RonnieStiggs]

I want to thank everyone again for the guidance, I discovered the thread was not repaired before. I received the tools on Friday and set to work immediately. While it was quite butt puckering the instructions that the time cert came with were clear, the build of the tool did indeed help keep the tool center before it started cutting new threads, and with the new insert the spark plug threads and seats well. Crisis averted!

After starting it back up it was running real rough, and would sputter out and die without the gas pedal applied.
I performed the following tests

• Checked for spark on all cylinders (all good)
• Checked to make sure the CSV is still doing good (it is)
• Removed spark plug cables one at a time to check for change, cylinders 1,2,5, and 6 saw no change when removed, if 3 or 4 was removed engine wouldn't start at all
• Removed spark plug wires from 1,2,5, and 6 all at once engine fired up and ran exactly as it did when they were all in
• Since I know we've got spark to all cylinders I checked the fuel injector lines to each cylinder, no fuel getting to the injector on the effected cylinders, fuel flowing freely to the 2 that fire
• Went back to the injector pump, same story, 1,2,5 and 6 no fuel leaving pump, 3 and 4 has fuel pumping freely
• Looked through the forum, my BBB we saw that we could remove a panel off the side of the pump to see a bit of the injection plungers, enough to see if they're operating at least. Plungers 3 and 4 are moving up and down, the others are stationary.

[ii]Pulled the oil inlet banjo fitting to see if oil was present (with the engine off and cool pressure at this fitting was built up enough to spray some oil out at the initial removal)[/ii]
[/list]

As it appears that the 2 that are moving are the two closest to the oil inlet I am assuming that the rest aren't getting enough oil, or are stuck closed and oil is failing to get introduced into them. Is there a way to move clean or lubricate the injection plungers without removing the pump from the car?

I did not attempt to remove the actual injection plunger as the diagrams lead me to believe they are insanely complicated.

[Kevkeller]

That is a very odd problem. The engine ran a few days prior but now the majority of your fuel pump pistons are not moving. I’m no FIP expert but I did pull mine out to loosen up a couple of my pistons one time.

I assume that they are stuck in the full up position. You can remove the fuel injection lines along with the check valves from the offending pistons and using a brass or aluminum rod tap the piston down. You can do this in the car.

The important question is what would cause those to freeze up after running a few days earlier. It sounds like they were getting lubrication. Maybe a call to one of the pump rebuilders would give some insight.

I’m wondering if the fuel getting to the FIP is enough. I know you bought a new pump but I’m wondering if the multiple filters have clogged up from sediments in your tank.

[RonnieStiggs]

Before my current trials and tribulations the car had been sitting for about a decade, I'm assuming the same sort of gunk that gummed up my csv is doing the same to the affected FIP plungers. My plan, if I can gain access to where they're suck is to give the effected location a spritz of carb cleaner and/or seafoam to dissolve whatever the gunk is.

If I do pull the valves at the top of the plungers is there anything additional I have to worry about (springs under tension flying out or anything like that)? It was the only thing stopping me from pulling them before

[Kevkeller]

No there’s nothing that should come out when you remove the check valve. Obviously keep dirt form falling in.

I could understand if the car sat for 6 months without turning over the pistons might seize from varnishing but it just ran shortly before this problem. Very strange.

[RonnieStiggs]

I could understand if the car sat for 6 months without turning over the pistons might seize from varnishing but it just ran shortly before this problem. Very strange.

I think, because the previous issue was the CSV being stuck wide open, fuel was getting into all cylinders of the engine regardless of the FIP working properly.

No there’s nothing that should come out when you remove the check valve. Obviously keep dirt form falling in.

There was a spring, but it was not under pressure so no crisis occurred when I removed the fitting at the top of the pump. Here are some pictures to go along with the descriptions of what I found and did. (in short, no change in fuel delivery)

• I started by removing the pump side of the fuel lines on all cylinders so I could get them out of the way
• As cylinder 1 (FIP top, closest to the cabin of the car) was the easiest to get at, and wasn't moving or passing fuel I started there, removing the fitting and discovering the spring inside, and seeing the valve for the first time.https://i.imgur.com/pqmOtJV.jpg
• Using Needle Nose pliers I removed the valve pin (for lack of a better term) and inspected what I could see https://i.imgur.com/ftVuikm.jpg other than checking for cleanliness I'm not sure what I should be looking for here, but I didn't see anything dirty or marred up.
• I then set about cleaning the removed components with carb cleaner https://i.imgur.com/SITKQ9x.jpg (focusing almost entirely on the valve pin) https://i.imgur.com/WAiA4nQ.jpg
• While the valve pin was out I cranked the engine over as a check and fuel sprayed out of the valve like a fountain, so, fuel delivery seems good.
• I reassembled everything after cleaning and there was no change to the effected cylander's fuel delivery.

I had a very limited time today so I only checked the FIP valve for cylinder 1 before I had to button it back up, but fuel is still not running through after re-assembly. I plan on pulling the FIP valve for cylinder 3 or 4 (the working ones) tomorrow to see if i can spot any physical difference. My only thought is the valve pin I pulled had a channel in the middle that may be for alignment of the pin but may also meant to be clear all the way through for delivery of fuel, and it definitely isn't (from top https://i.imgur.com/JjDY9D8.jpg) (From Bottom https://i.imgur.com/uA8nzmb.jpg). I can't seem to find any pictures of a new pin from these angles, so I'm not currently sure, but from how I think this style of valve is supposed to operate the pin shouldn't be hollow (If I haven't made it clear already I clearly don't know for sure).

[ja17]

If the fittings are removed from the IP, the electric fuel pump will gush fuel even if the pistons in the IP are stuck. The early pagoda engines had "cone type" check valves with a spring. Later pagoda engines used a ball/spring check valve. In this case the spring is part of the check valve assembly and is not a separate part. If you remove your check valve you will see the cylinder and a small plunger (piston) in the middle if you crank the engine the plunger/piston should move up and down. If it does not move, the piston is stuck in the cylinder. You can remove your fuel pump fuse to prevent fuel from gushing out of the IP.