ve pump over flow valve

[gozapper]

Do the VE pumps have a over flow valve?
If so , if bad, will keep it the the engine from starting?
I have 92 that will not start without a shot of ether. It will run until shut down and still will not start without a shot of ether.

I know that ether is bad. I disconnected the heater before doing so.


Thanks , Tom

[Tacoclaw]

Have you checked your fuel inlet and return lines for wet spots? That sounds like its losing prime more than anything.

Have you tried pumping the lift pump or cracking a couple injector lines before you start it?

[gozapper]

Did all that.

I removed the solenoid plunger, connected a line from the IP to a electric lift pump, aline to a fuel can, still have the problem,

I have bled the injectors and have fuel there.

How can I tell if the IP is bad before I spend the bucks for a rebuild?


Thanks, Tom

[oldestof11]

Turn the idle up a bit and see if that helps.

[welderboy250]

If it has fuel and won't start that is a compression problem.

[E9-500]

The end cap is loose on the head of the injecton pump. The big plug (cap) in the center of the head and rotor comes loose over time and will not allow engine to start. Engine will start with starting fluid and run.
Need a special socket to torque. Or drive to the nearest Bosch shop and see if they will torque it on the truck.
The cap is a crush fit and over time it will back off causing your problem. Todd

[PToombs]

I've never seen one of those loosen up before. There is an overflow fitting, it holds the return line on the pump.
Sounds like a losing prime condition to me too, but it may be a bad pump. When you had the electric pump on it did you run it, then shut it off and it wouldn't restart?

[ahale2772]

I'd like to hear more about what E9-500 is saying, sounds interesting

question is, when it runs, does it run strong/normal?

[E9-500]

I have "fixed "many VEs with hard starting due to a loose end cap. When Bosch makes the head it
drills it the way thru . Of course a oring alone will not contain the high pressure developed so the cap has a crush wedge on it. When torqued(cap) it acts like a head gasket, but over time it will relax a little bit just enough to allow
the plunger not to develope high pressure for starting and combined with low cranking speed you get a hard start.
Using starter fluid will start it.And because of higher engine speed it will stay running may also have low power.
This problem has nothing to do with the over flow valve. It has a hole in it , its not like a p-pump valve that has a spring and check ball.

[E9-500]

Also in the few years I've been reading this site I've never heard anyone talk about a loose end cap. Two months ago I got a call about a dozer with a no start problem. Had a 4bt in it. I took the socket and a torque wrench. In two minutes it was running . Loose cap. All I did was retorqued the cap. Saved him alot of money. Many of the bread trucks had this problem.

[ahale2772]

yeah, Its an "orifice return" not a valve, anyways, thanks for that tidbit of VE info E9, good stuff

I would assume the cap would leak eventually? any idea what the TQ value on it is?

[E9-500]

Cap could leak, but when that would happen the engine most likely wont run.. Torque is 60-80 NM or 59 LBFT.
Think of this cap as a head on an engine. Over time and miles the head bolts loosen up and the head gasket relaxes. Then you have a blown head gasket right? No compression ,no power ect... Thats the way this end cap is.
Over time and miles it relaxes a bit. The plunger cant develope enough pressure at cranking speed to pop the injectors.But if you crack the lines loose it will pump fuel out. It also could be the 10mm bolt that is in the center of the cap. It has a copper gasket under it.
Hope this helps.

[ahale2772]

helps quite a bit, just dont get where the pressure from the cab bleeds off to when/if it relaxes

[E9-500]

Years ago when the p7100 pump came out it had a copper gasket under the delivery valves. Over time these gaskets would break, erode, ect... The engine would then have a miss. Well the fuel would escape around the DV via the broken gasket not letting high pressure to be reached to open the nozzle . There was no external leak. The fuel is
dampened due to a broken gasket . In the VE the fuel is dampened because the cap is loose. I guess you could say it (fuel) is just being squished around. A loose cap will give you a hard start problem.

[welderboy250]

I guess the reason it doesn't leak externally is because of the oring on the end cap and the return port they drilled in the head to keep anything more than case pressure from building on the oring. To tell u the truth I thought uwere full of poopy cause I thought it would cause an external leak until I remembered the relief passage. The little bolt in the end cap would cause a drip if it were loose. I've seen that before on tractors.