Turning up IP primary pressure?

[GREASE FIRE]

i am still trying to figure out my no-start-when-cold situation and have it narrowed down to a few things.
there is a small shop in town that rebuilds injection pumps and i went to talk to the owner and he gave me an idea on how to test the primary pressure on the pump. He said take an extra injector line and injector and put it in place of one of the lines on the pump and see if that extra injector pops when cold cranking. If not, it could be that the primary pressure needs to be turned up.
He suggested 1/2 turn (done by inserting an allen wrench at the fuel inlet of the pump).

has anyone solved a similar problem by doing this? Will this actually turn up the fuel supply to engine or just increase the pressure at the IP inlet?
i have a few other things to check before i try this one but i just want to know what i am doing before i do it.

thanks,
Paul

 

[icanfixall]

No is the short answer. What happens when you turn up the fuel is you are adding more fuel per injection pump stroke. Not pressure. Before you try to turn up the fuel you need a pyro. Then you know what the exhaust temp is before and after. Otherwise burning a piston is a big possibility. You probably have an air leak somewhere and should repair that first. How many miles are on the injection pump and the injectors. They usually last 100,000 miles there abouts. Some longer ans some shorter. Are any injectors wet... If so thats a leak and air will be pulled into the fuel system.... To do what the pump mechanic told you to do will have some effects you don't want plus is really a tuff thing to do. Nobody on this forum has done that or at least they have not posted about doing that.

 

[dyoung14]

I messed with this screw your talking about in the fuel inlet of the pump, all i noticed was alot more rattle!!!! enough to drive you crazy

 

[GREASE FIRE]

No is the short answer. What happens when you turn up the fuel is you are adding more fuel per injection pump stroke. Not pressure. Before you try to turn up the fuel you need a pyro. Then you know what the exhaust temp is before and after. Otherwise burning a piston is a big possibility. You probably have an air leak somewhere and should repair that first. How many miles are on the injection pump and the injectors. They usually last 100,000 miles there abouts. Some longer ans some shorter. Are any injectors wet... If so thats a leak and air will be pulled into the fuel system.... To do what the pump mechanic told you to do will have some effects you don't want plus is really a tuff thing to do. Nobody on this forum has done that or at least they have not posted about doing that.

thanks for the reply.
i would really like for it to be an air leak - but the thing i don't understand is why would it start on the first crank with the block heater plugged in and run fine, but not start at all w/o the block heater? If it was an air leak, wouldn't there be trouble starting either way?
i have also wondered about the injectors - but again, why would they not pop when cold but pop with the engine warmed up with the block heater?
The IP was rebuilt less than 50K ago (i don't know the exact miles though).

i had an extra starter, new in box, so i put that on just in case it was a cranking rpm issue. It does crank a lot faster - but still no start....

i would be really thankful for any other suggestions right now - i am really at a loss to try and figure this one out.

thanks,
Paul

 

[OLDBULL8]

Are you runing straight diesel, waste motor oil or vegetable oil?

Are you sure all your glow plugs are heating?

At 40-60 degrees they should be on for about 10 seconds.

To check for air in the system. There is a brass schrader valve on the filter, back out the valve a little, attach a clear hose into a can/jar, have someone crank the engine and observe if bubbles/air is coming out, if so you have air getting into the system. DO THIS WHEN YOU HAVE A NO START.

 

[franklin2]

Are you getting stinky white smoke out of the tailpipe when it won't start? If so, you are getting fuel.

 

[Agnem]

If the truck starts fine when hot, your symptom is more indicitive of a glow plug/air leak/starter spin problem. If you have smoke at the tailpipe, you have fuel at the injectors.

 

[icanfixall]

How long does the glow plug "wait to start" lite stay on.... If it starts with the block heater that usually means the glow plugs are not working. Don't start messing with the injection pump just yet. Thats the last item you want to change settings on when you have a no start issue.

 

[GREASE FIRE]

i have a manual glow plug relay, activated by a momentary push-button switch on the dash. The stock relay also works but i have temporarily disconnected the red wire that turns on the relay when you turn on the key switch because i have to use starting fluid sometimes.
But, i have tested to confirm the gp's are getting power with the manual system - they are getting 9 volts. They are brand new Berus. Is that what they are supposed to get or should it be 12 volts? It was the same voltage with the stock relay.

thanks,
Paul

 

[GREASE FIRE]

i just did another test: i had a friend stand next to the tail pipe and watch while i cranked it. I gave two long cranks and there was no smoke at all. i did use the glow plugs for about 10 seconds both times.

if i plug the block heater in it starts right up....

 

[Dieselcrawler]

i would test the glowplugs. if it is plug in and starts then they aint working. even if they are new u might of held them on to long and burnt em out already. take a test light, hook aligator clip to + on batt, then unhook the pigtails going to the glowplugs and tap the probe to the glowplug terminal. if no light, plug is bad.

 

[Agnem]

How did you measure this 9 volts?

 

[GREASE FIRE]

How did you measure this 9 volts?

i disconnected the wire that connects to the end of the glow plug and put a volt meter to the connector, then cycled the glow plugs. i did this to a few of them. So, that's the voltage going to them.

i don't have the kind of meter that measures amperage draw so i can't confirm that part - but i know the gp's are good and they are getting power. The cabin light dims when i cycle them. I can't rule out the fact that perhaps they are not getting hot enough but if that is the case i have no idea why.

 

[OLDBULL8]

Nine volts is about right when GP's are cycling. Check battery before trying to start should be 12.3 to 12.7.

if i plug the block heater in it starts right up....

That is really strange. From all you've said, it appears to be a fuel problem.

To check for air in the system. There is a brass schrader valve on the filter, back out the valve a little, attach a clear hose into a can/jar, have someone crank the engine and observe if bubbles/air is coming out, if so you have air getting into the system. DO THIS WHEN YOU HAVE A NO START.

Have you done this yet?

 

[OLDBULL8]

The IP was rebuilt less than 50K ago (i don't know the exact miles though).

Does the timing marks look like this on the IP or close to it. The lighter mark is on the IP toward the passenger side, darker on the mounting flange,