1984 300d, 151k will not start

[Mercury]

1984 300d, 151k will not start

Over the last few months several symptoms were observed.
Idle continued to get rougher with a lower rpm, Idle screw was continually adjusted in to max, ramp damper was set full in.
No power coming off of idle, but high speed response ok.
Cold power (in Texas summer) was very bad, got a little better as engine warmed up.
The last night it actually ran, I had to keep throttle wide open at stops, or the engine would die.
I was then able to run a diesel purge through, but it did not start afterwards.

What I have done:
Replaced all three filters.
Replaced lift pump
Streched the fuel return spring out
Used temp fuel tank in the engine compartment (think diesel purge) as source and return of fuel with no change

Observations:
When cranking, fuel comes out the return line, but will not come out of any of the cracked inector lines
Spray pattern and pop (1900psi) of injecters are good.
Disconected the vacuum line into the fuel shutoff valve.
Used external vacuum to test fuel shutoff valve, and could hear it open and close.
I have run WVO, currently pure diesel in tank.

Where I am now:
Glow plugs are not an issue at this point, as no fuel is getting to the injectors.
The lift pump is working.
Battery and starter are in good shape

What else can I do? I detest the thought of replaceing the IP, only to find out a line was clogged...

[toomany MBZ]

It would seem you have adjusted a couple of items so far out of spec, it's going to be "fun" trying to figure out your problem.
Idle adjust, the engine should be at a very high idle, you may want to come back some.
Rack damper, if too far in, the you won't have any fuel getting to the pump, hence no fuel out of the injectors.
Stretched fuel return spring, get a new one.

So, back off the RD bolt first. If you start, be aware your idle will be quite high, take precautions.

[JEBalles]

So fuel comes out of the IP return line, and no fuel comes out of the cracked injector lines. Take off the hard lines, to see if they are clogged (unlikely), check the tank screen. What WVO setup were you running? It could have taken out your IP.

[Mercury]

The 3 filters that were replaced were:Tank screen, Spin on, and clear plastic.
I'll go try the rack bolt at half.

[lietuviai]

Do you fully heat your WVO when using it? It's possible for it to gum up your IP over time especially if it is not fully heated before it gets to the IP.

[Mercury]

lietuviai, very possible on the IP gum up. Heating was added recently (not initially). The tank screen was replaced due to severe growth clogging. The rack damper and idle adjust was done in response to a problem, and they provided a temporary fix. Current readjust back out did nothing. If the gum up was an issue, the last diesel purge may have dislodged something and the created a downstream clog? I do use a racor biocide.

[lietuviai]

I'm not sure how Diesel Purge would work on any WVO gumming.
You're best bet now is to crack your injector lines while cranking to see if any fuel is being delivered.

[Mercury]

Just tried again, still no fuel comes out of the cracked injector line

[kingdoc1]

Mercury,
Your symptoms sound exactly like a friend of mine who runs WVO in his 300d's. After about 30,000 miles the engine idle becomes terribly rough and eventually the car will not run anymore. The solution seems to be simple--he simply spends $800-$1000 for a IP rebuild and the car is purring like a kitten again, at least for another 30,000 miles. Doesn't seem very cost-effective to me. I hope the IP is not your problem but I wouldn't be suprised.

[lietuviai]

That doesn't sound good. Sounds like it may be clogged delivery valves to me but I am no IP expert.
I'm just wondering if by trying to remove one the delivery valves like it's done in the timing procedure to see if fuel dribbles out, could test to see if the pump itself is at fault or not.
I would see if one of our more IP knowledgeable members could chime in on this.

[moon161]

Greasy?

Single tank SVO
Single tank blend
Unheated 2 tank
Or heated 2 tank?

Filter? Dewater? Hot Pan Test?

Has engine set w/ grease in it?

[Ian White]

Take the injector lines completely off and crank the engine, you should see fuel spurt from the delivery valves. I was having very similar issues but it turned out to be a faulty fuel shutoff valve. If no fuel is being ejected through the delivery valves, I suspect you may have a clog in the inlet lines or possibly worn barrels and plungers in the I.P.

Good Luck!

[Mercury]

With injector lines removed , no fuel comes out. tried with fuel shutoff vacuum line attached and again removed.
Single tank, 50/50 wvo/diesel mix summer, 30 wvo/70 diesel winter.
filtered to 1 micron, dewatered, hot pan has very small bubbles indicating smaller presence of water then pump diesel. biocide and cetane boost each tank.

[Mercury]

Ian, One last answer, Engine performance has been decreasing , until the point of non-functional, so it has not been sitting. Daily use until nothing.

[kingdoc1]

Mercury,
Do you have a spare IP that you could swap in? I don't know exactly what the WVO does to the IP, but every time my friend has this problem a rebuilt IP has always fixed it.