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Discussion Starter · #1 ·
Here's my dilemma, I bought an 87' f350 with a non running VE 12v in it (to use the frame/axles/motor/trans in an upcoming project). I ran some fuel directly to the lift pump, charged the batteries and bled the system and found good fuel at only the second injector from the rear. So I purchased a supposed good pump from a member on here with good trader feedback, after installing it and bleeding the system I found the same thing. Great spray at the second injector from the back, all the others just drizzle out fuel.

Obviously I should have bought a new/reman. pump, however now It's got me thinking what are the chances that two pumps have identical failures like that?

And also what else could possibly cause such a situation? I cant think of anything short of clogged injector lines...5 of them.

Sean
 

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Does either pump turn? I doubt you have two bad pumps. Do the shut off solenoid work? Seems fishy to me that both pumps do the exact same thing...
 

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Discussion Starter · #3 ·
Does either pump turn? I doubt you have two bad pumps. Do the shut off solenoid work? Seems fishy to me that both pumps do the exact same thing...
both pumps turn, in fact the other 5 cylinders DO increase flow in order (a couple even "spurt" fuel) but none spray like #5. I assume the FSS works, it clicks with 12v...on the old pump it was gutted.

Seemed fishy to me as well. Hopefully I can find an answer here.

thanks
 

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Are you opening all the injectors at the same time when your trying to bleed it, sometimes it takes a while to get all the air out of the IP.
 

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Discussion Starter · #5 ·
Are you opening all the injectors at the same time when your trying to bleed it, sometimes it takes a while to get all the air out of the IP.
I've tried all injectors, i've tried 3 injectors at a time. I've also gravity fed fuel right into the IP and it seems to take very little fuel.

Since someone will likely ask soon: no, i'm positive I didnt lose the timing key while switching pumps, and I can see the shaft turning through the front.

I've actually been at this problem for quite a while, but this truck as a whole is a side project of mine. So I fabbed up the whole truck around a non running 12v. Its ready to atleast yard drive now, So this has been my first inclination to really attack the problem.

Thanks for the help gent's, keep it coming.

Sean
 

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Have you checked the LP's fuel pressure, it's best to check it after the filter. 3-5 PSI is what the stock LP puts out.
 

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Have you tried giving it a little shot of ether? Disconnect the air heater first.
I just replaced a bad IP myself and with the bad one on it would only start with a shot of ether. Also the bad pump could be turned over by hand, the new(used) pump I had to use a wrench to turn it (it would sort of pop as I turned it) Once I got the new(used) pump on and bled the injectors it starts right up.

Also are you pumping the lever on the lift pump about 30 times before you try to start it?
 

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Discussion Starter · #8 ·
Have you checked the LP's fuel pressure, it's best to check it after the filter. 3-5 PSI is what the stock LP puts out.
I have not, I don't have a gauge. However I did switch to a new lift pump, and I've plumbed it up so its gravity feeding right into the IP.
 

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Discussion Starter · #9 ·
Have you tried giving it a little shot of ether? Disconnect the air heater first.
I just replaced a bad IP myself and with the bad one on it would only start with a shot of ether. Also the bad pump could be turned over by hand, the new(used) pump I had to use a wrench to turn it (it would sort of pop as I turned it) Once I got the new(used) pump on and bled the injectors it starts right up.

Also are you pumping the lever on the lift pump about 30 times before you try to start it?
Honestly it doesn't even seem to want to start with a shot of ether. Neither pump can be turned over by hand.

I think Ill switch back to the Lift pump, but maybe use a clear hose straight to the IP with a bleeder in the top, to eliminate all the pre-IP lines and separator (drawing fresh fuel out of a can).

If it still doesn't start, or pump at all then I guess Ill take the injector lines off and see what's happening at the back side of the pump while turning over.

Sean
 

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Honestly it doesn't even seem to want to start with a shot of ether. Neither pump can be turned over by hand.
Batteries charged up good? Sounds like its not spinning fast enough.

I have 2 batteries(truck was originally a Diesel so it has 2 battery trays), and I also changed starters, I put a rebuilt on and it spins twice as fast (I suspected the original one was going bad, but I got in the deal for a bunch of parts)
 

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Discussion Starter · #11 ·
Batteries charged up good? Sounds like its not spinning fast enough.

I have 2 batteries(truck was originally a Diesel so it has 2 battery trays), and I also changed starters, I put a rebuilt on and it spins twice as fast (I suspected the original one was going bad, but I got in the deal for a bunch of parts)
I usually use a Very HD jumper pack...It spins her over pretty damn good.

Ill try again with Ether later today or tomorrow.
 

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I'd try cracking the fuel lines on the back of the IP and see if its doing the same thing there.
 

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Discussion Starter · #13 ·
I'd try cracking the fuel lines on the back of the IP and see if its doing the same thing there.
I was thinking the same.

Unfortunately I got 5 inches of snow yesterday and its currently 5 degrees outside before windchill...in other words, i'm not touching it!

Does anybody see a problem with bypassing the filter/separator, and pre-IP lines with a clear hose from the LP to the IP with a bleeder up top and pumping fresh fuel out of a can? just to simplify the problem.
 

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I was thinking the same.

Unfortunately I got 5 inches of snow yesterday and its currently 5 degrees outside before windchill...in other words, i'm not touching it!

Does anybody see a problem with bypassing the filter/separator, and pre-IP lines with a clear hose from the LP to the IP with a bleeder up top and pumping fresh fuel out of a can? just to simplify the problem.
I wouldn't bypass the filter, if you have 3-5 PSI at the bleeder for the filter then you your going to have enough pressure for the IP.
 

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To rule out injector line problems...small critters, or rust and debris etc...I'd disconnect the injector lines form the back of the pump and from the injectors. Then place paper towel under the lines at the injectors, and blow compressed air through the lines.

Just a side note on being able to spin an IP by hand easily. This is usually what happens when the two big springs break inside the injector pump. This is a fairly common problem, and happens more times then you'd think. Pulling the IP and cleaning it out, reseal and a Couple new springs will get that pump back up and running.

It is possible that the fuel pressure control collar has come loose in both pumps. It can cause a situation similar to this...though usually all 6 injector lines just dribble fuel instead of only 5.
 

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Just a side note on being able to spin an IP by hand easily. This is usually what happens when the two big springs break inside the injector pump. This is a fairly common problem, and happens more times then you'd think. Pulling the IP and cleaning it out, reseal and a Couple new springs will get that pump back up and running.
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:thumbup: Good info, when it warms up I am going to check out the pump I moved.
 

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Discussion Starter · #17 ·
To rule out injector line problems...small critters, or rust and debris etc...I'd disconnect the injector lines form the back of the pump and from the injectors. Then place paper towel under the lines at the injectors, and blow compressed air through the lines.

Just a side note on being able to spin an IP by hand easily. This is usually what happens when the two big springs break inside the injector pump. This is a fairly common problem, and happens more times then you'd think. Pulling the IP and cleaning it out, reseal and a Couple new springs will get that pump back up and running.

It is possible that the fuel pressure control collar has come loose in both pumps. It can cause a situation similar to this...though usually all 6 injector lines just dribble fuel instead of only 5.
I'm going to run out to the shop and check the old pump tonight, IIRC neither pump can be turned by hand. Also I haven't noticed any leaking fuel from either pump.

Is it fair to say that if the pump doesnt turn with a wrench, and doesnt leak fuel that my problem is probably something other than the IP?

Im going to try to work on it a bit this weekend if I can bare the cold, or drag it into the shop.

Thanks again for all the input, Very much appreciated.

Sean
 

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Discussion Starter · #18 ·
Just checked the old pump, no way can it be spun by hand...its hard enough with a wrench. I spun it 360 deg. and all the "clicks" seemed the same.

I remember specifically that the new pump was the same, as I needed to spin it to install it.

Now i'm half tempted to tear into the old pump and see if anything is wrong.
 

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Discussion Starter · #19 ·
Also the new pump came with a 3200 gov spring installed and the pump HAS been tampered with.
 
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