Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: mistertj on November 14, 2023, 22:59:22
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Had this issue a year plus ago. The engine just cranks and cranks and eventually starts to fire and eventually catches. Last time it turned out to be the cold start valve. Just wasn't getting voltage. Turned out to be a dirty fuse and was fixed by turning (rotating) each fuse to make better connections.
Did not use the car all summer and up until now. The symptoms are back...engine just cranks and cranks. I have a lamp connected to the cold start solenoid...it lights and I can hear it "click". Disconnected the fuel line from the cold start valve and aimed it into a plastic bag tie wrapped to the line. It gets fuel but I'm thinking maybe just not enough for a good spray. Is there an easy way to check the fuel pressure? Where and how would this be accomplished? The fuel pump runs and puts out enough fuel to support the engine running once it gets started but I'm wondering if there is enough pressure for the cold start nozzle to spray nicely? Suggestions?
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Hello, maybe the actual valve, filter or the nozzles are blocked, it describes on here how to clean the CSV and test it
https://www.sl113.org/wiki/Engine/ColdStartValve
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Is there an easy way to check the fuel pressure? Where and how would this be accomplished? The fuel pump runs and puts out enough fuel to support the engine running once it gets started but I'm wondering if there is enough pressure for the cold start nozzle to spray nicely?
If you have the connectors/adaptors, I believe the best place to measure fuel pressure is at the port on top of the main fuel filter canister. Others my have better suggestions.
The best place to measure fuel flow rate is at the return line to the tank - measures full fuel circuit. Do not under estimate flow rate, it is as important, or probably more important, than pressure. This is per Baron Youngman, a member here who has rebuilt a few hundred fuel pumps.
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Sorry for the delay but finally got to check the fuel pressure coming from the pump. Screwed a pressure gauge into the top The larger fitting) of the engine fuel filter holder. The photo says it all. Just a tad over 1 psi. So, before I just change the pump...will drain the fuel from the tank and then change the tank filter. While I am in that area, change the small filter that I have in the line between the tank and the pump and at the same time, check the input filter to the pump itself. If none of those show clogging/restrictions...then I'll pull the pump and put in the spare that has been rebuilt. While I'm all messy with that, will put in a new fuel filter at the engine. Will let you know what the results of all that are.
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If I may...
Perhaps others will have another explanation and suggestions for such a low pressure. I am assuming you checked the pump is working...
But if you are getting to filters, I would do the tank filter last. If you have additional in-line filter - do it first. If the gauge shows pressure after the main filter, I would do it next. Then the screen in the pump (you may need to hit it with the impact gun, the nut may be difficult to move and it is difficult to hold the pump on its hanger if you do not want to remove it).
Reason I am suggesting to check the tank filter last is because it may be very difficult to unscrew it... I would do the easier ones first.
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Hi Paul - Thank you for the input. I screwed the gauge into the top of the filter where the larger nut is. Don't know if that is before or after filtering. With your input though, since it's been years since I last changed the main filter, will start with that first and work backwards toward the tank. Next would be the filter at the pump inlet. I'll pinch off the fuel hose and do that. Yes...an impact wrench on that fitting, otherwise might damage the pump mounts and still not get it loose. Again...thanks for the input.
Tom
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MisterTJ,
Good job, you're on to it! You know all the filters and as Pawel said, start with the easy ones! My fuel tank screen came out easy the first time I did it, but every car is different. The first time I changed my main filter, a couple weeks after buying the car, the canister was 1/3 full of rust!! Clearly, I had fuel tank issues and the previous owner had maintenance work issues.
I can't wait to hear your findings. Best of luck.
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I do not want to take it too far not to side-track you in the wrong direction, but there may be other topics - clogged lines, e.g. tank-pump or return line or you may have the flower pot issue, in which case the fuel supply will be fine until low fuel level, when fuel does not get to the flower pot from above but through a narrow passage near the tank floor.
So, again, there may be other issues for this low pressure than filters, I am not sure where is the best to start.
P.S. I spent half a day on my fuel tank filter. I had to finally drill it through and cut the threads from inside the hole to loosen it. I was very scared - working with drill and saw blade practically inside the fuel tank...
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Hi Paweł - Had the "flower pot" issue years ago with the original fuel tank. So much rust flakes that it would block fuel getting to the filter. I replaced the tank to fix. What I am going to start with is the filter since it's long overdue for a change. Then I may pull some hoses to check on the fuel flow before I go back and mess with the pump input. Oh...on the tank filter, I made a crude tool to unscrew that filter. I've only used it once though. (See photo)
Tom
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Then I may pull some hoses to check on the fuel flow before I go back and mess with the pump input.
Check the flow rate at the return line at the fuel tank. That checks the whole system. If there's a restriction, work your way backwards through the lines/system.
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I'm looking at the fuel filter canister. Looks like I can do everything from inside the engine bay...no? It's been so long but I seem to remember having to do a lot from above before dropping the canister cup into a container below.
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Temporarily plug off the fuel return line to see if pressure increases. Reason; if the return check valve is stuck open, it will casuse a severe fuel pressure loss.
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Joe - Thank you. Where is the check valve anyway?
Tom
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Mechanical Fuel Injection pump. Do some searches for it, you'll find threads discussing it. I'm not sure what's in the tech manual about it, but worth a look.
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Injection pump outlet fitting. First check if you have this valve. I do the fuel line and look inside the fitting. There is or there is not a small hole. Its presence or lack of it indicates if the valve is there, but kill me, I do not remember if the hole means valve is there or vice-versa, you have to look up. It is connected with the presence of the T connector presence at the return line near the fuel pump.
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OK...today's activity. Pinched off the fuel return line...no change in pressure. Still read about 2psi, which is 1 psi more than yesterday. Then proceeded to change the fuel filter. Did it from up top but put what I call an absorbent diaper....one of those white things. Oh, the remaining fuel in the filter canister was kinds dirty but one might expect that. From there proceed to the fuel pump input filter. Think that's a 28mm and with a very small torque driver, it undid. Not too dirty but flushed with some spray carb cleaner. Put it all back together and checked the pressure...kinda down to nothing now. As a just in case, added a couple gallons of fuel. Tried again and still no fuel pressure. Next I pulled the fuel line coming from the injector pump and stuck the hose into a pint container. Flicked the key on and watch the fuel flowing out...maybe a pint in about 5 seconds. Anyway, will put in a different fuel pump next. Not sure if I'll have time tomorrow but whenever I do, will let you know the results. Cheers
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Next I pulled the fuel line coming from the injector pump and stuck the hose into a pint container. Flicked the key on and watch the fuel flowing out...maybe a pint in about 5 seconds.
I believe the proper flow rate is 1 liter / 15 seconds. Flow rate is very important and not always related to pressure. Keep at it!
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A pint in 5 seconds sounds about right. Let the pump warm up a bit, then measure - maybe more precisely. You need above 0,6L in 15 seconds (poor result but may work), 0,8L would be ok, 1,0L is good. So a pint in 5 seconds may be ok.
But you need it at the end of the return line.
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Thought about it early this morning...really early. How can I have that much fuel flow and so little pressure? Checked pressure this morning with a different pressure gauge. The pressure is there....hmmmmm! So will order a replacement gauge but in the meantime, back to checking the cold start components.
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Yes, your pressure is good! Also, with an 230SL engine most check valves are built into the large banjo type fitting at the return line connection of the injection pump.
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Thank you Joe.
Put it all back together and tried to start. After what seemed like forever, it finally started to fire on 1 cylinder, then a couple more kicked in but the others never did. Pulled spark plugs and they were all black. Put in new plugs but still only finally got it to fire on a few cylinders. Checked exhaust tubes temps and cylinders 2, 3 & 4 were much lower than other three so I replaced the injectors in those cylinders with known good ones. Filled injectors with gasoline and tightened all connections. Again, cranked forever and finally caught on a few but the others never caught. I'm at a loss as to what might be going on so gonna take a break.
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Then maybe you are experiencing the spark issue on those dead cylinders. I would perform my favourite exercise of watching blue lightenings around plug connectors in a dark garage when engine is running.
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Taking a break but will give that a try when I return.
Thanks
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Try cracking loose the injector lines at the injector one at a time while the engine is running. You will hear each cylinder kick off or kick in, when tightened, if fuel is being delivered.
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Been a year since I last posted on my 230SL cold start issue. I have made no progress since I haven't really done anything until now. Summer is long over so nice cooler working weather is here, I'm back at it. I did, however, do some things...filters, etc and have fuel pressure of around 7psi. (See photo) I also followed a couple of the previous suggestions and disconnected a few of the lines to injectors 4, 5 & 6.(See photo) Cranked the engine numerous, numerous times and no fuel coming out of the lines. No fuel to the injectors is the symptom and certainly would cause hard / no starting.
So...before I start disconnecting metal fuel lines, I wanted to ask for any input as to what might be going on and what my next steps should be before I start taking things apart. Car has been sitting for a year so there might be an air lock or whatever. Thank you in advance for any thoughts.
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TJ, last year one of our members had several cone valves in his R11 injection pump that were stuck open. These same cone (check) valves may be binding or stuck shut on your fuel injection pump. Since you already have the fuel lines to injectors 4, 5 and 6 disconnected, remove the other end of one (or all three) of these lines from the injection pump and confirm the cone valves aren't seized up. There's some good photos here: https://www.sl113.org/forums/index.php?topic=36768.msg269483#msg269483.
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Charles - Where are the "cone valves"? Here's what my pump looks like.
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Charles - See photo.
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There's a good write up on these valves in here:
https://www.sl113.org/wiki/Restricted/PagodaNotes?action=download&upname=PNv8i1.pdf
And how to remove them:
https://www.sl113.org/forums/index.php?topic=15754.0
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Awesome! Thank you.
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The cone-valves and springs would have been under the 19mm outlet fittings, but looks like you've got the later ball-valves.
There's a few photos of the R11 cone-valves here: https://www.sl113.org/forums/index.php?topic=24659.msg177150#msg177150.
Just curious, is that an R11 pump? thanks, Charles
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Sorry for any confusion. The photo is of a spare injector pump and I had forgotten that Pacific Fuel Injection had modified it for me to the ball valves. It is an R11 otherwise. I will check the pump that's in the car during the week to see what's going on. Thanks though for the memory refresher. It's been a while since I last messed around with the pumps.
Thanks for the info though.
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Hi Charles - Think you're right on the stuck cone valves. I did what you suggested and tried to pull the valve out. (5 & 6) Doesn't want to move. (Photo) Took a look at another R11 pump and was easy to pull the valve and stem out. (Photo) Any suggestions on getting the stuck ones out?
Tom
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I'd apply some penetrating oil to each valve, let them sit awhile, and then try twisting them loose. If unable to get the valves loose, I'd just pull the valve and the seat both out of the pump. If I remember correctly, the only thing holding each seat in place is the nylon seal ring.
If the cone valves are badly corroded or you damage them getting them loose, you might want to consider replacing all of them with those ball-valves in your other pump. Not sure if you ever had a problem with hot-starts, but when these cone (check) valves wear out, the metal fuel lines will leak-down and make hot-starts difficult.
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Charles - Thanks for the info and suggestions. What I was thinking of doing is do the penetrating oil and then after a day or two for any of the cone valves that don't loosen, pull the valve far enough out so I can grab the top piece with pliers and twist/rotate to loosen. If it comes loose pull the cone shaft out and push the base back in. Hopefully most will loose with the Krill oil penetrant. If I do need to replace any of the plastic rings, any idea of a source?
Tom
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Check to make sure the rack in the pump is not stuck. A stuck rack is usually caused by one or more stuck pistons under the cone valve.
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Hi Joe - Thank you for the input. I'm guessing that I have as many as 5 stuck valves. Was hoping to fix without taking the injector pump out of the car but guessing that it's got to come out to do the job right. Any suggestions on "un-sticking" the valves without actually pulling them out?
TJ
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Joe, Charlie and any others. Decided to leave the injector pump in the car. (Photo) With home made tool, cone valve assemblies are coming out smoothly. I have removed cone valves to #1 and #2 cylinder thus far. They are frozen solid. (Photo)I plan on removing all of them aa I think most are frozen, remove sealing washer and let soak in penetrating oil for remainder of the day. I have another pump that I could rob for parts but would rather fix this one. Any idea on the part number for the sealing rings and a possible source. I see sealing kits for the whole pump but would rather purchase just the sealing rings. Also not sure that the part number I have for the whole kit for the right pump (R11).
TJ
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Finally got all of the R11 Injection cone valves out. Came out easier than I had anticipated a tool I made, some time ago. All the valves were stuck and took some coaxing (hammer and pointed driver pin) to come apart. Once apart, spray carb cleaner and some Q-Tips cleaned them quite well. The gunk on the valve mating parts was like one might find on the inside of an old carb...that brownish stuff. It all brushed off though with the solvent and q-tips. Now the valves slide just like new. Going to try to find new seals but if I can't soon, I'm going to reinstall the valves and not replace until I find some at a later date. See photos to include the removal tool I fashioned. Made the job very easy.
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..Going to try to find new seals but if I can't soon, I'm going to reinstall the valves and not replace until I find some at a later date..
Tj, glad to hear you got the cone valves loose. Seems I bought some seals (separately) from Robert Fairchild a few years back which saved me from having to buy the entire kit. Robert Fairchild (Jerry Fairchild Industries) may be reached at http://www.fuelinjectioncenter.com (530) 474-4646.
If you use the old seals be sure to keep a lookout for leaks around the outlet fittings when the engine is running. gosh, I had no idea those seal kits had gotten so expensive: https://www.authenticclassics.com/Bosch-Injection-Pump-Seal-Kit-PES-6KL-70-120-Model-p/auth-009203.htm.
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Charles - Thank you, I'll give Robert a call. Did business with them about 5 years ago. So...no strangers and I was really impressed. He checked out one of my pumps just for the price of shipping.
TJ
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For Joe Alexander and any others interested. Well, very proud of myself that I was able to free up all six of the cone valves. Following that I checked the rack as Joe advised. Much to my disappointment, the rack is stuck. The pump is still in the car but would like any suggestions on how to unstick the rack while it is still there. Thanking you in advance.
TJ
Quick update - Did more research to find additional info. Found a 2015 article here on unsticking pistons by JA. Anyway I'm attaching a photo showing what I'm guessing is the top of my pistons so I plan on getting some hardwood dowel material and tapping to see if I can free up. Still...any additional info would be much appreciated.
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If anyone wants to get the seal kit cheaper, this is where I got mine from.
https://mercedes-classic-parts.com/en/product/dichtset-injectiepomp-m127981-m189-v-nr-f026t03028/
I also purchased the governor seal kit from them as well.
Very reasonable prices, for me, not having to pay VAT helps subsidise the shipping cost to Australia.
Doug.
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Current status. All cone valves were frozen but managed to get all of them freed up. Then found most or all pistons stuck/frozen as well. Have been using penetrating oil for the most part but first started with carb cleaner. Have been tapping on the piston surface with an oak dowel...now on second day doing that in addition to adding more penetrating oil a few times a day. Think I may have motion on one piston. I read somewhere that it may take a week or two. Curious as to where the liquid is going?
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Status update: Cone valves removed and eventually got them unstuck and moving nicely. Pistons, with lots of carb cleaner, penetrating oil and coaxing with dowels, are unstuck vertically but rack is still stuck. Still trying not to have to remove injector pump but it may be inevitable. Ideas welcome.
TJ
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Latest status update. Hooray! The rack is free. All the soaking and tapping worked but I was at a loss on manually unsticking the rack. I'm sure that it's written somewhere but since the rack rod has a threaded hole, I made a puller of sorts. It was all the coaxing the rack needed. A little rough at first but after moving the rack back and forth numerous times and having the starter rotate the engine, everything is pretty smooth. I'm going to put a little Marvel Mystery oil in the cylinders and exercise the pump more over the next couple days while waiting for new cone valve seals arrive. In the meantime I am also going to check the fuel in the tank and inspect if there's much rust in the tank. We'll see.
TJ
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Be sure to use the correct torque on the 19mm injection pump fittings.
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Joe - On the site I saw some discussion on 18 ftlbs but in reading through some of my books, I saw 25 ftlbs for the pressure valves.
Tom
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Yes I believe the 230 SL is 18 ft. lbs. and the the later SLs is a little more . It depends on the pump version.
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TJ, I responded to your earlier email. Perhaps OBE at this point but I found the bag the Bosch seal-kit came in and unfortunately part numbers for the valve seals were not provided in the literature. looks like you're well on your way getting that FIP squared away..
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Charles - The diagram that you posted here is the one that through me off. It looks similar to our R11 but it isn't. That's where I got the incorrect sealing washer number of 1 410 206 020. It's item 16 on the drawing. Cheers
Tj
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A happy ending...car is fixed. Cause I'm guessing was lack of car use allowing the fuel to dry up allowing sediment to form and stick the cone valves and at least one piston. Followed the guidance available on this site...choke cleaner, penetrating oil and tapping on the pistons for days eventually freeing up everything. Made a small puller to extract the cone valves and a "puller" to coax the rack into moving. Car is running pretty good now.
TJ
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That's good news, well done!
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yes, glad to hear that! :)
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…car is fixed. Cause I'm guessing was lack of car use…
When I was “interviewing” potential restoration shops back in 1999, the ONE THING every shop asked is, “…it hasn’t been sitting long, has it?”
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Well...kinda. It started over a year ago as a hard starting. Then because of other priorities, I let it stand for just about a year. Then it became more of a stuck rack issue. Now I will start her more often as well as adding StaBil to the non-ethanol fuel.
TJ