Calling P7100 Gurus

m880cummins

m880cummins

New member
Joined
Apr 29, 2013
Messages
142
I bought a 4bt a few days ago mainly for the long block. Tonight, after replacing gaskets and swapping some parts, I decided to test run it to see how everything works before I sell the injection pump. I wanted to make sure the pump works before I sold it.

Engine runs smooth at idle and up to 1600 ish RPM. Once past that, white smoke and popping. I removed the afc and fuel plate and the engine will dump black smoke on a quick throttle up but still sputter with white smoke. From this, I can say the rack moves as it should and I know there is no air in the system. I removed the timing pin on the side of the pump with the engine at TDC and could see the locking tang but it looked bent up because it was more towards the top of the hole. I am going to borrow a timing tool tomorrow and mess with the timing even though I think it is right. Also getting another set of injectors to try.

If it is pump related and the rack moves freely, what else could it be?

Here is a video of it running.

[ame]http://i393.photobucket.com/albums/pp19/desertkart340/ebay%202014/2D865883-A62D-418A-BC4C-B933844630FF_zpsvvj20ojt.mp4[/ame]

Charlie
 
Timing on a cold engine will do that, or poor injectors.
 
Poor/low lift pump pressure.
Too low of timing.
Bad injector(s).
DV/Holder Issue.


But my bet is low lift pump fuel pressure and/or low timing or both.
 
Dv/holder issue is definitely worth checking. I had a pump that would idle smooth and between 1400-2200 RPM it chugged and acted extremely weird and low on power. Turned out to be a DV washer was smashed and not sealing all of the way.


The smallest thing can really ruin your trip to a dyno day :(
 
Thanks guys. I have some p7100 series seals washers and gaskets. Where is the DV seal?

I will throw on a different lift pump and check timing.

Thanks
 
Don't "throw on another lift pump", rig up a gauge. Crank it up, and rule that out.
Check your timing next. If that's not the issue, THEN start looking elsewhere. No reason to tear into the pump, before you rule out this other stuff.
 
m880cummins said:
Thanks guys. I have some p7100 series seals washers and gaskets. Where is the DV seal?

I will throw on a different lift pump and check timing.

Thanks
Click to expand...

It is under the holder. Like mentioned check other things first. Many don't even run DV washer (seal).
 
zfaylor said:
It is under the holder. Like mentioned check other things first. Many don't even run DV washer (seal).
Click to expand...


I have recently learned about these. I have never seen them in a 215 pump. Are they truly needed
 
I had some time to fiddle with it today.

Swapped injectors, lift pump and tried running it again. No difference. I changed the Overflow valve out for the tork tek I had on my truck which was bottomed out on adjustment. Hard to hand prime with that much pressure!

So I am going to stick a gauge on the pump to see PSI but I doubt there is an issue. The only thing I am left with looking at is the DVs.
 
Update,

Checked timing. Was spot on.

Fuel PSI hovers around 30psi (no snubber) at any RPM

Removed DVs and found the #2 DV spring broken. Snagged one from another pump and it ran somewhat better on top end

I am beginning to think that it just dumps fuel and since there is no boost being made, it just floods out on fuel at higher RPM
 
I noticed that you're running it with no boost.
I know they run way different with no boost, as opposed to having at least a crossover on it.
Give it some air and it'll probably be a whole different engine.

Mark.
 
97rada said:
I have recently learned about these. I have never seen them in a 215 pump. Are they truly needed
Click to expand...

I remove them if I do a set of DVS. The one I found messed up in my pump was aluminum so I couldn't see it.
 
Well I threw the towel in on this... Pump is off the engine. I had the DVs out, all looked fine besides one broken DV spring, I pulled two barrels and they looked fine. I installed new washer seals on all of the DVs. Everything was cleaned thoroughly and saw no issues.

In my research I saw there is a tiny spring inside each DV holder which is meant to keep the fuel from going back towards the pump. All I can say is the pump should have one or all of the DV springs replaced ($14 each) and be flowed. It should be fine after that. I imagine the lack of air for the engine didn't help in diagnosing the performance...
 
You must log in or register to reply here.
Top