87-300TD Not Starting - Injector Pump?

[1987-300TD]

Good Day Everyone!

I am having issues starting my 87 300TD. She cranks but does not seem to come close to catching...

* replaced the o-rings on the injector lines in November. Starts were hard before the change. She seemed to crank for at least 30-60 seconds before starting. After the change, there was little to no difference.

* brought battery to AutoZone to have it fully charged. Attempted starts had drained it to 49%.

I also recently had the engine cleaned to start troubleshooting oil leaks. It appears as though the Injector Pump is one of my culprits.

To that end, I ask ye gurus, Could my non-starting issue be because of the oil leak at the Injector Pump?

I am also questioning the filter in the tank as I have not checked that in quite some time. I am going to add 5 gallons of fuel tomorrow to see if that helps. :-)

Any advice is greatly appreciated!

Thank You all for sharing the knowledge!

g

[Diseasel300]

30-60 seconds of cranking is *ABSURD* on a 603. It should start faster than that even with a dry filter change. Even with no glow plugs. Even with a worn out IP.

You likely have a serious air ingress problem somewhere, or a worn out lift pump that's letting the fuel system bleed down.

Pull off the return fuel line going back to the tank and crank the engine. You should have fuel spurting out of it like a heartbeat.

[barry12345]

You have checked that the glow plugs are functional?

[sixto]

Does the stop lever pop up when you turn the key to glow? Sometimes the shutoff mechanism gets sticky or the key switch doesn’t release vacuum holding the stop lever down.

With a means to stop a runaway engine, remove the vacuum line to the shutoff actuator, confirm the stop lever is full vertical, hold it up if you have to, then try starting the engine.

Does it run normally when it starts? If it’s low on power you might have a clogged cat.

When you confirm adequate fuel and glow, remove the plug on the #1 exhaust runner that takes a 17mm socket. If the engine starts more easily, the exhaust system is clogged, likely at the cat.

Sixto
98 E320s sedan and wagon
02 C320 wagon

[1987-300TD]

Good Morning and Thank You All! I am heading to the girl shortly. :-)

Diesel300: I was going to check for fuel by cracking the lines at the injectors. I may try the return instead. :-)

Barry: The GP have less than 30K miles on them. Alas, I have not checked that they are actually working. I will do that. :-)

Sixto: The stop lever does indeed move when the key is in the "glow" position. As for the cat, it was removed before I purchased the car. :-)

When she ran last week, she felt smooth. My issue has been starting for the past several months...

I will get back with hopefully good news...

g

[sixto]

As a quick test, clamp the main return line from the filter block to the tank then start the engine. If it starts more easily, the regulating valve on the hidden side of the IP might be stuck open. Don’t run the engine with the return line clamped!

Sixto
98 E320s sedan and wagon
02 C320 wagon

[Diseasel300]

Originally Posted by sixto

As a quick test, clamp the main return line from the filter block to the tank then start the engine. If it starts more easily, the regulating valve on the hidden side of the IP might be stuck open. Don’t run the engine with the return line clamped!

Sixto
98 E320s sedan and wagon
02 C320 wagon

The 603 doesn't have a "regulating valve", it's a drilled orifice in the overflow bolt. Pressure in the rack is set by volume flowing against that orifice, not against spring pressure.

[sixto]

Hmm... I’m pretty sure I’ve seen 603 IPs with the sealed ball spring thingy vs the 617s removable bolt style. But I don’t bet on my memory.

This is a 602 IP but that thing with the ball is an orifice rather than a spring valve?



How about vacuum in the fuel tank?

Sixto
98 E320s sedan and wagon
02 C320 wagon

[Diseasel300]

Originally Posted by sixto

Hmm... I’m pretty sure I’ve seen 603 IPs with the sealed ball spring thingy vs the 617s removable bolt style. But I don’t bet on my memory.

This is a 602 IP but that thing with the ball is an orifice rather than a spring valve?

The pressed ball bearing seals the assembly and the weak spring and disc valve inside. The disc valve serves as a non-return valve, it does not regulate pressure. You can blow through one of these types of valve with your breath the spring is that weak. Pressure is regulated by flow resistance against the orifice.

[if6was9]

You should be able to verify glow using a cheap Harbor Freight non-contact infrared thermometer. The exact temp is irrelevant you just need to verify that the glow plug is heating up at all. A couple of cycles of glow should heat the part of the plug exposed. Check the glow fuse if the car has one.

Once you verify glow you need to be certain fuel is getting to the nozzles, crack the lines at the injector and observe. If you've got fuel good, if not rig up an under hood fuel bottle with a couple hoses and eliminate the tank/lines as a potential problem. Still no fuel means filter or lift pump issue or other IP fuel circuit issue.

Another diagnostic would be using the block heater to warm the engine for easier starting. If it starts easier with block heat then that would point to a glow plug issue. With a single dead glow plug and a cold engine the OM 601/2/3 can be a bear to start.

What's the ambient air temps when this starting problem manifests itself? I've had an occurrence where over time water in the fuel gets trapped in the secondary(canister) filter's cotton medium and then when it gets cold enough that water saturated filter will severely restrict fuel to the IP.

Don't know how cold it gets where you are but synthetic oil makes a night -and-day difference with cranking speed in cold temps.

[Mxfrank]

How much fuel is in the tank? The fuel tank has an usual baffle device in the bottom. Above 1/4 tank, fuel can flow over the top of the baffle and reach the filter screen. But below that level, there's an odd orifice system which can become clogged and prevent fuel from reaching the pickup. If filling the tank solves the problem, then you'll need to have the tank cleaned out. This is especially true of TDT's, because of the horizontal tank.

Another possible problem area is the fuel heater, which can develop air leaks. If the above doesn't work, just use a length of hose to bypass the heater and see if that helps.

[tyl604]

Lighter weight oil will make a lot of difference even if you have other problems with ignition. My '81 300SD still starts in about half a second every time in any weather.

Do you actually have a TD - that is a station wagon?

[1987-300TD]

So a funny thing happened on the way to troubleshoot my girl. A friend who was going to be helping me stopped by with her 91 300e. We wound up fixing a bunch of stuff under her hood as there were a bunch of issues. (Not the least of which was a serpentine belt down to 2 ribs...)

We got to my car to discover that both my main battery and my spare were both dead. Dropped them off to get charged. When we went back to pick up the batteries, one needed more charge time and the other needs to be replaced...

So troubleshooting is postponed for a day...

I did however spy dark oil around the lift pump. As I just cleaned the engine 2 weeks ago, I am surprised to see oil there. Thoughts?

Responses:

* If6was9 - I do not believe it is glow plugs. We are in Las Vegas and although we do drop below freezing, we are usually temperate. :-) My hard starts were occurring even during the summer months.

* MXFrank - Fuel level seems to be a possibility. I seem to have harder than normal starts if the level gets below 1/4 tank.

* Tyl604 - I like the synthetics also. Use them in all our vehicles. My wife's Honda is super quiet after an oil change. :-) And yes, my girl is indeed the wagon. :-)

Again, Thank You All! I will let you know how tomorrow progresses.
g

[Diseasel300]

Originally Posted by 1987-300TD

I did however spy dark oil around the lift pump. As I just cleaned the engine 2 weeks ago, I am surprised to see oil there. Thoughts?

Oil will come from one of two places:
1: The paper gasket behind the lift pump.
2: The side gasket for the injection pump.

#2 is probably more common. The rubber gasket dries out and oil leaks out. It's harmless, but annoying. Remember that the IP has oil circulating through it when the engine is running.

[1987-300TD]

Diseasel300, do you happen to have part numbers for those gaskets? :-)

Thank You!!!