New Timing chain, now wont start
 

I have a toughie, folks. My project car is a 1981 240 D in which previous owner replaced the timing chain and then it wouldn't start. Only 100K miles. He said probably bad glow plugs. NOT! So far I have checked cam timing, adjusted valves(WAY OUT!) , bled the system(lots of air bubbles top of filter, and cracked the injector lines. NO fuel coming to injector lines! He also had removed the vacuum pump(WHY?) which I replaced. The vacuum pump is driven by the timing chain and I assume is keyed to the injection pump. I can see the vacuum pump turning when I manually rotate the engine. Is it possible the injection pump is not turning ? IE., could he have disconnected it somehow? Is there any way to tell if the injection pump is rotating short of removing it entirely? Note I have done the timing chain R&R twice on 123 cars and everything went smoothly so I don't see how he screwed this job up. IDEAS!??

I have 18 years working as a diesel mechanic and have several times still managed to get fuel injection pumps timed wrong. Don't know about you but you can't have your A game going all of the time. And the person first changing the timing chain had what type of skills?

Other Members have lost control of the timing chain and had it drop down inside while they are rotating it in. They ended up with issues.

You need to check the timing chain itself and be sure that it is an Iwis/jiwis Timing Chain.

Also you said you are getting no Fuel at all up to the injectors. That means you could be having more then one issue.

So check the Valve timing to see if that is correct then you are going to need to check the fuel injection pump timing to see if that is correct.

If it won't start after that you need to deal with the no starting issue.

If your fuel injection pump has a plug on the right side that you need a 17mm wrench to turn to remove it; it has the port for the Timing/Locking Tool.

You can rotate the Engine to top dead center on the compression stroke and then continue past to 15 degrees after top dead center.

You put something under the 17mm plug to catch the about 1/2 cup of oil that is going to come out when you remove the Plug.

With the plug off look inside and see if the blade type tab is centered in the hole. Try not to view it on an angle if you can.

If it is not lined up your fuel injection pump timing is off.

Thank you 911 for your thoughtful informative reply. Yes it is OEM chain. The old chain was in the new box. Cam timing is perfect @ TDC. Even if the timing is off shouldn't you be able to get fuel out of the injectors? No fuel comes out at all. I tried starting it while pumping the primer pump with no luck. Previous owner was a marginal mechanic. EG the adjusting nuts for the valves were chewed up probably from needle nose vise grips. I had to hammer my offset wrenches on a few of them! I will go hunting for the 17mm plug. On the engine side or the fender side? Thanks in advance. Looks like pump timing check is in my future.

You are right that you should get fuel up to the Injectors even if it is out of time. However, in this last year people have been having trouble with that on Cars that have sat unused for long periods of time.

Personally am for using one of the methods to get it started by spraying something into the intake.

For me that would men un-plugging the large electrical connector at the Glow Plug Relay so that the Glow Plugs are not going to go on and careful use off Starting Fluid.

What careful means you spray into the Turbo Inlet if you have a turboed Engine while most important someone else cranks the Engine. The other person starts cranking getting some air flow going and you spray and use the minimum needed to start the Engine or find out if it is going to start.

If you do that you are avoiding spaying in a bunch of Starter Fluid and running to crank the Engine and having a huge amount of evaporated Starting Fluid hit the Engine all at one time. Done it that way at work many times on various Diesels with no issues. My Boss used to do the spraying while I did the cranking.

Or you can find some of the thread on the other stuff people have used.

You got to get fuel to injectors before worrying about timing. Keep cranking and pumping the manual pump with the lines loose enough at injectors to allow them to leak. Once you start getting fuel out tighten that one down then crank some more to get out of next one, tighten it and, on a healthy engine, should be able to get it to crank with 3 working.

Vac pump is not timed to anything, just the injection pump.

Thanks 911 in advance. Well I was able to check the pump timing with The mercedes source kit and it came in at 2 deg BTC! No wonder it wont run. I soaked the pump in the lubromoly diesel cleaner overnite. I was able to only advance the pump 4 degrees and now it sits at 6 deg BTDC. I think the previous owner must have removed the pump? Or could he screw up the timing by putting in a new chain? I got another 18-20 degrees to go before it's timed and I assume I have to pull the pump out and rotate it one direction or another. How much and which way? I am lucky to have an old 240D pump on my bench to compare things and I see the collar with the notched teeth but I don't know which way to turn things. No info on how many degrees each tooth is. Any Ideas. I would like to avoid trial and error because it is a bear to get to the bolts. BTW I didn't have any 17 mm plug bolts to check timing on my pump, just a fill plug(18mm) and maybe a drain plug(?) at the bottom which was smaller like 14 or 15. Regards. Hugh

There is no plug on drivers side (USA vehicle) of pump? Do google search and read up on removal/installation of ip. The vac pump has to come off. Sounds like cam and crank are ok.

Ya, well 240Ds have M type Fuel Injection Pumps Pumps and MW type Fuel Injection Pumps.

The older MW Fuel Injection Pumps have a plug that has a 14mm head and the later versions have the Plug with the 17mm head. Both those plugged holes are for a timing tool to go into. I have seen pictures of the older timing tool and I own one of the timing locking pins for the 17mm ones.

In the picture the red X marks the 17mm plug and in the next pic you see a 240D MW Pump with the smaller plug although it is not usually an Allen head type plug that I have seen anyway it is in the green circle.

I am not sure if the blade inside can be seen through the smaller hole.

I have no pictures of the M Type Pumps to reference so I don't know what is there on them.

If you go to the service manual and it has that you can use the A&B Light or the RIV method of timing on your Fuel Injection Pump you have a hole for that to fit into and there is a blade in side to actuate the A&B Light or the RIV method.

I see with your great pictures.It would be nice to have that nifty tool but I am doing the drip test method with high pressure. easy enough. I am assuming the lift pump is moving fuel from the tank and I see it is driven by a cam inside the pump on my old pump on the bench. I will try to pull the pump out today and see if the collar assembly is lined up with the mark on the flange. Previous owner had removed the vacuum pump for some reason and maybe he screwed up the injection pump timing. Is it possible to test the function of the cam driven lift pump? Does it have a rubber diaphragm or a piston setup.? It is a thrash getting to all the nuts holding the pump. I'll be in touch. If it doesn't start and run I guess it is a bad lift pump or lousy compression. After that I am out of ideas. Thanks

Because of the plastic lines it is not easy to T in a gauge to check the lift pump pressure. And when you can the needle bounces back and forth so much it is difficult to tell. Some have dealt with that by using liquid dampened gauges and some have used some sort of restricted orifice.

One person used that skinny plastic tubing that people use when they add on a mechanical Oil Pressure gauge and I guess the small inside diameter and the length of the tubing dampened out the impulses.

The Lift Pump is a piston type pump and is positive displacement in one direction and when the spring is compressed the spring tension move the Piston back I think the pressure was high enough it would hold the piston in that position till the pressure bleeds off. The Fuel Pressure Relief/Overflow valve determines the pressure.

Post 5 and post 11 have pictures of the innards I posted in a previous thread.
http://www.peachparts.com/shopforum/diesel-discussion/356205-can-617-injection-leak-into-oil.html

Note that if you are removing the big plug on the Lift Pump when you put it into a vice keep away from the thin flanges on the casting as they are easy to crack off.

Well I put the pump back in. V hard to line up to get the notched teeth to engage. I was able to advance it to 19 deg BTDC. I am waiting for the gasket. Can I just turn the pump(retard direction) and then reinsert it so I have enough rotation to get 5 or 6 more degrees of advance or is there a formula on how many teeth(to the R or L) on the pump flange? Lining it up with the mark is not giving me enough to get to 24 deg BTDC. I am also staring to wonder if my lift pump or the check valves are the reason I get NO FUEL TO THE INJECTORS no matter how hard I pump. I also do not get the chirping sound I am sup[posed to get after pumping the hand pump. I have a 1982 240 D and it chirps up a storm so that can't be good. Now What! Does the lift pump go bad or just the valves?

Well my saga continues. I managed to get the injection pump timed. It was 1 deg BTC but I indexed it and put it back in and set it to 24 deg BTDC. How it could be off 23 deg is beyond me unless someone messed it up. While I had the pump out I put in a new manual pump and 2 new check valvesI cranked it this am and still wouldn't start but am getting fuel to the injectors. I noticed blow by which seemed significant while cranking. I assume low compression. Stuck rings? Something worse? The car has set for 5 years in a barn before I got it. I guess a compression test is in order? If it's stuck rings would solvents like lacquer thinner or Berrymans help? This car only has 100K and looks it. As I mentioned it has a new timing chain and the valves have been adjusted and the cam timing is dead on. Anyone had experience with the harbor freight compression tester?

Uhh......That doesn't sound great. Where are you seeing the blowby? Typically the engine should be running to generate any meaningful blowby, even on a very tired engine or one with stuck rings.

If compression is low, yes a ring soak may and often does help. I'd try soaking the rings for days with occasional movement of the crankshaft. That engine has a rope rear main seal which could easily be damaged by solvents in the oil, I'd avoid cleaners added to the oil only soak them from the top.

I wasn't crazy about my HF tester.

Good luck!!!

Did you make sure that you were 24 btdc on compression stroke(#1 cyl)? because if it was 24 btdc on exhaust stroke then it surely won't run.

Thanks for your replies everyone. Mist is coming out of the breather cap/valve cover when cranking. I poured Parts cleaner(Berryman) in the cylinders to try to soak the rings overnite. only 2 cylinders held oil for more than a few minutes . The levels dropped fast but none held oil for long. Seems like the Berrymans going straight down into the sump. Probably stuck rings I guess. Turning the engine over with the crank pulley seemed a little too easy early on which made me uneasy. It was as easy as a gas engine. It wouldn't fire even with ether while cranking. I pulled the injectors and the tips were heavily carboned and a few of the injector parts were rusty. 2 nozzles were discolored. Terrible sign which I assume could be SVO caused damage?? I wonder if there is any hope. I did a spray pattern check and one injector was just a stream,one had a crappy sideways pattern and the other 2 were less than perfect but functional. Pressures were 1700 with 3 and about 1300 with one. If my guess is SVO caused damage I wonder if I am at the end of the line. Any ideas on freeing stuck rings besides parts cleaner? If the injector has rust I assume the injection pump might have rust. Putting in new rings is too much of a job with these old diesels I think. I have put new rings in my toyota corolla over a weekend with the engine in the car and it was a simple job. Am I looking at a used engine?

Waste vegetable oil burners can be bad news.


Personally if the car otherwise looks good you might consider trying to locate a good used engine. Depending on where you live and some other factors. It may not be that expensive.

Well, thank you in advance for your advice. To recapitulate My 240 D has 102K miles and the previous owner put in a new timing chain and after that it wouldn't run. No other info. I went over it and the valves were way out, the timing was way off(ie 1 degree BTDC). I set these to spec and pulled the injectors. they had very poor spray patterns so I put in 4 new nozzles and fixed that problem. I was worried about sticking rings because the injector nozzles had terrible carbon buildup and cleaning them released a orange thick scum which I guessed to be veggie oil? There was also corrosion on some parts. Once reassembled with 4 good nozzles I soaked the pistons for a week with lacquer thinner and MMO. Finally I decided to order a compression tester(should have done that first!!) The numbers were 95,90 ,80 and 80. Compressed air came out the intake manifold after setting the #1 piston at TDC. Bad sign. What happened? My guess is that the previous guy screwed up the TC installation and then cranked it over bending the valves? Any ideas from the resident geniuses on this site? If I need a valve and head job is there advice? Like reusing head bolts, putting in new guides etc? Any other ideas to be sure this is the problem? If this car wasn't in cherry condition I'd throw in the towel. O rust, O dents, good seats.

Sounds like removal of the head is next. If the cam is timed right. The blowby coming out the oil filler hole while cranking. May be stuck rings with wvo usage or scored cylinder walls.

I am wondering about his need to replace the timing chain as well. It should have not broken or been worn at the claimed milage. I would check the serial numbers to see if it is the original engine. Or the odometer reading is way off. That is not unusual with the 123s.

Waste vegetable oil residue can turn with sitting to a very strong glue in piston lands. Head work like many other things is not particularily cheap now.

A decent used engine checked out properly before purchase may be financially the easiest way . If you remove and install it yourself.

I am not a resident genius incidentally. Regardless of what the wife claims.

Cam towers will break before valves will bend.

Engine oil while using WVO does become sticky if not changed frequently. I was wondering about gummed up valve guides. Polermized base oil is known as a result of burning WVO. The valve faces could also be in a mess. Observing the valve train while rotating the engine by hand might be a move.

To me there is just a little too much going on with that engine. What an owner does with their car is up to them. Someone dealing with the consequeces or aftermath of what they did can be another story

Bent valves if present should be stopping the ability to rotate the engine. You mentioned the valve lash was way off.. Far too loose or far too tight? Far too loose could be valve face buildup of some sort. Or the owner did this. Normally these engines lose valve lash clearance never gaining it.

I personally have some negative bias about burning vegetable oil. Perhaps honestly acquired. Back in the day people would post problems they were having. Without mentioning the WVO they were using. After awhile if the problem was not typical. I asked them what they used for fuel. When they fessed up it became easier. Sometimes it took a lot of time before they admitted it.

Like most members we try to help other members. We are fortunate in having some really knowledgeable guys on board. I am but an greenhorn in comparison. The really sad part to me was they thought they were using free fuel. Many of the ensuing nightmares proved otherwise.

I guess the next step is head removal. The previous owner did not say why he replaced the timing chain and I should have asked him. The fact that the timing was way off and the valve adjustment off suggests to me the possibly the chain broke or slipped a cog. I assume if the chain broke the cam assembly would have been damaged. It appears just fine. A friend who is a cummins mechanic agrees with me that the valve(valves) may be bent nut not so bent that the engine can't be turned manually. So I will pull it and take a peek. I ordered a borescope and will try to see if I can view the valves thru the manifolds. Obviously can't thru the injector holes. I am looking for a used motor or head but they are few and far between in the mountain west. No one drives rear wheel drive diesel cars out here because of the ferocious cold and heavy snow. Even carpart.com has very few.A wrecked and running car is probably my only option. I have rebuilt a few motors but these old diesels look more difficult than what I have tackled before. The common notion that they last a million miles is nonsense unless they have had meticulous maintenance. I have several cummins trucks with a gazillion miles that still run with much less maintenance and 40-50 yr old tractors that still run almost like new. I do love the generally excellent engineering of these W123 cars and think they should never be scrapped unless they are rustbuckets but at some point it becomes a point of diminishing returns trying to find old serviceable parts and even new parts. I have out one AT and one engine in these cars in the past and it is an easy and fast chore compared to some modern cars and trucks so I guess I will stick with it for a while longer. I do have a restored 300D which now runs flawlessly but these 240D cars with their taxicab simplicity appeal to me.

You likely have a broken timing shaft.

This shaft is responsible for driving the Lift pump from the chain movement

and keeping the injection pump timed to the engine crankshaft.

This is why the previous owner took off the vacuum pump... to get a look at the bolt behind the injection pump drive gear.

He probably gave up to due to the complexity of taking that gear off of the IP timing shaft. There is likely a stripped out press fit pin holding a timing chain guide below the vacuum pump, which you will discover some day.

best wishes.

the shaft I am talking about goes from the injection timing device - driven by the chain - all the way through a bearing in the block where it meets up with the injection pump.

to replace this shaft, you will need to pull the injection pump and the vacuum pump

You are likely to find a sheared / mangled woodruff style key and a cracked shaft at the thin end near the bolt that holds it to the timing device.

Put a 240d engine wanted add in our parts wanted section of the site. Something may turn up. Within a reasonable distance.


If you are going to continue. There was a reason I asked if the valve clearances where far too tight or far too loose. Far too loose may be signifigant.


I also found your compression readings where odd. All cylinders read about equally very low. Personally I might want to check if the crank pulley indicator really corresponds with top dead center on the number one cylinder.


The easiest way would be to remove the injector and bring the engine a small distance from from indicated TDC. Fill the cylinder with oil. Best to rig a straw as a guide. Rotate the engine the oil level in the clear straw or tube will very accurately indicate TDC. Then check the pointer. Since you do not know why the chain was changed or if they had the engine pulley off. A waste of time perhaps then again you have some strange things.


On the other hand the current situation may just be a result of burning WVO. The residue in the rings has gone solid with time. Plus the valve faces are a built up mess. What I am suggesting otherwise is a long shot.


I just got to thinking what if this is a true low millage engine. If so it would be wrong to not check every possibility out. Even if unlikely. another thought is if the past owner burnt a lot of questionable WVO. Plus the combustion was poor. A more or less equal buildup of by products of the WVo that did not burn. Got built up. This could account for the similar compression readings. Even the excess valve clearances.

Had equally low compression readings, it was the gauge. Numbers that even are a good sign, numbers that low if accurate are not; however, the low could be due to valve timing. I'd follow barry12345's advice and be certain that the piston is at TDC and then/next confirm the pointer is at zero, then/next confirm the camshaft is lined up.

Every adjustment (except valve clearance) on that engine relies on an accurate TDC pointer, if it is off so are the other adjustments. If it's off it is like building a house on a sloped foundation...

Good luck!!!

Well I finally
+ received my compression tester and the numbers were terrible, between 70 and 90. All the air was coming out of the intake manifold. Perhaps exhaust as well. Crankcase was quiet. This was a lot of trouble for little yield. My guess is bent valves c/o the previous owner's screw up. So now it's up to me whether to pull the head and take a look see or retire it to the back of the lot as a parts car. A used motor is a possibility of course but the brake system is totally shot from MC to all 4 calipers. At some point it makes sense to call it quits. But no rust and no dents and only 100K miles makes it worthwhile...........except for the durn transmission is an automagic. If it were a manual.......maybe.

I would put an engine in it and fix the brakes. You have nothing to lose because it is worth very little as is. Throw $1,000 in parts and you'll have a nice, serviceable, comfortable, interesting car to drive.

I'd be thrilled if the only issues on my cars were engine and brakes. That's the easy stuff. Body work gets expensive and fixing all of the little stuff takes time and can cause frustration.

Cleaners were used to loosen carbon now the engine is cranked over where does that
carbon Go? out the valves, both intake and exhaust.
Recheck valve lash if loose guess what?