Bruce M

Can a 91.5 Cummins Engine be started by connecting 12 volts to the fuel shut off valve and turning the engine over without preheat? The truck has Been sitting for two years when I purchased it for $300. Also disconnected the high pressure lines from the injectors to check for flow.Got diesel out of all lines. Still it does not start. What should I look at next?

jogl

Yes, I just started my '92 W250 wreck like that the day before yesterday. It had been sitting for about the same time.

It took quite a bit of cranking before it finally fired off then ran fine. Once I got it going it fires right off now.

Wish I would have only paid $300 for my wreck, good find!

Look for nests in the intake. Can you smell the fuel in the exhaust outlet? All I can think of for now.

Good Luck,
JP.

12valve@heart

You may just need to bleed your injectors but you can always try running it on WD-40 if you suspect a fuel problem.

Cowboy_Customs

Apply 12 volts to the fuel shut off to see if it clicks. If not, I belive u need to pull it out and gut it. There is a lever on the pump to shut the engine down manualy, if the shut off valve is inop. The preheaters u wont need either.

Bruce M

Was told that the 91.5 had a bad lift pump by the second owner who was given the truck with the starting problem. It was a work truck and boy was it over worked. Has a lot of cut wires and everything has been patched in one form or another, also has a utility bed. Just trying to get it running to see the condition of the running gear. Knowing that its getting fuel to the injectors, I was thinking about adding one injector to a high pressure line not connected to the engine to see if the pump output is high enough to pop the injector.
Do you guys have any other thoughts?

wannadiesel

It should start with a lot of bleeding. Leave 3 lines loose, crank it, tighten the loose lines and loosen the tight ones, crank again. Sometimes it will take 3 or 4 go - rounds of this to get it to fire on 3. Once it lights, try to keep it running while you tighten the other 3. The air should work its way out in a few minutes of fast idling.

Bruce M

Connected one injector external to the engine, it would only drip and not produce a spray pattern. Could it be the pump pressure is not high enough or the flow rate is low or a combination of both???

jogl

Double check that there is lots of fuel getting to the IP. Loosen the supply fuel line (the one on top at the front of the IP) and crank the engine. Make sure that you loosen the line and not the fitting going into the pump. There should be a lot of fuel come out. If not then check filter and lift pump.

If there is lots of fuel then start back in to bleeding the injector lines. When you crack a line at the injector fuel should squirt out forcefully and plentifully.

If you can't get lots of fuel to the injectors then back to troubleshooting at the IP.

JP.

Bruce M

JP,
The lift pump looks new. It has a suction filter which I was thinking of bypassing.
The filter after the LP does not have a water drain and looks old. Thats one thing I have to change. Will open the line to the IP to check flow as you suggested. Also will try bleeding as Dave said. Any other thoughts???

jogl

If there is lots of fuel getting to the IP no need to bypass or replace anything yet.

First get fuel to the IP, and then to the injectors, and then, with luck, you are done.

JP.

BearKiller

We cranked and ran my engine, sitting in the shop floor, not in a truck.

It had been in storage for a few years.

We stuck a draw line,and return line, in a gallon jug, put 12-volts to the shut-off solenoid, touched a wire to the starter, and she immediately kicked off.

Just the merest breath of ether will work wonders on a hard-to-start engine, if bleeding doesn't seem to get it.

Bruce M

I connected all the injectors external to the engine and got them all to produce a spray pattern. Put them all back in the engine and still no starting. Next I removed the #1 valve cover and disconnected the high pressure line from the injector and cranked the engine over by hand. Fuel would come out of the line when the exhaust valve was closing. I would think the fuel should flow just after the intake closes before TDC.
Does this mean the IP input shaft is 180 degrees off from the High pressure plunger??

jogl

That does not sound right at all. Probably a good time to check out the timing.

Does it look like the IP has been off previously?

JP.

Bruce M

Yes, the pump has no timing mark and no black paint on the body.
You can only see the timing mark on the engine.

Bruce M

The first time I did a seal job was on my son's VE pump on his VW,found that the pump Cam can go on two different ways, either inline with the input shaft woodruff key or opposite thus having the ability to put the high pressure plunger in line with the woodruff key or 180 degrees off.
Because the pump is spraying just before the exhaust valve closes, I think the IP Cam was set 180 degrees off with respect to the high pressure plunger.
What do you guys think??