What can go bad inside the pump that would allow air into only 1 DV and corresponding line & injector???

Here's whats happening.... Engine has been running great (needs oil change but seems irrelevant) New fuel filter in January.
Had to go rescue my Mom last night when her 1500 gasser torched a water pump, when I got there about a 40 mile trip one way I noticed it was smoking at idle ( it has never smoked at idle unless its cold) Kinda greyish. Thought maybe its the new load of fuel I got (looks kinda pinkish) IT IS NOT red offroad.

This morning it fired right off like always.... But had a miss on one cyl. thought must have an air leak. Took off going slow down the road after a short warmup, and the missing cyl started popping on. It was actually blowing smoke rings. Then it kicked in and started firing normally.

Got to work about 15 miles and at idle it was missing again. Cracked inj lines at injectors 1,2,3,5,6 and they squirt fuel out normally and start missing.

Cracked #4 and out squirts a huge load of air and fuel ( actually hit underside of hood with the spray) and of course thats the cyl thats missing. So reved it up and opened the line at the dv and same thing loads of air out of it.

#4 is the only one doing this. Is the injector not seating and compression is blowing up the line or is something wrong inside the pump where #4 is the only one getting air?? Sorry for the long post but this has me cornfuzed. Thanks

 

I would swap 3 and 4 injectors to see if the problem moves.

 

Do you hear any extra clatter under the hood when #4 doesn't fire?
I'm thinking you have a sticking plunger in the pump.

 

No extra noises from engine or p-pump. But this morning #4 never did start firing. It would pop every now and then, but not run.

i will swap injectors today to see if its the injector or the pump.

 

Keep us updated on this. Im interested in what you find.

 

I had the stainless washers under the DV's push out when running it hard one day. It basically wouldn't fire on #4 and sometimes #5. I would pull the DV's out and see what it looks like in there.
After checking injectors of course.

 

Ive heard other talk of washers under thier DV's, mine doesnt seem to have any. Ive looked both times ive been in there and sure didnt see any? I have a set of 181's comming so ill be back in there in a day or two and will look again. Has anyone else found there to not be any in thier pump. mines a 911 180hp version. Thanks

 

no washers in my 215 either.

 

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stock600 is right. Some of the P-7100 fuel pumps do not have the washers while others do.

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John_P

 

Well I pulled #'s 3&4 to swap... and found the nozzle on #4 is split. Straight across 2 of the holes up each side of nozzle about 1/4".

What would cause that. I do not tow heavy and never let EGT stay over 1200 for more than a few seconds.

 

Well that sucks but at least you know what it is. If you can buy just 1 injector that should be an easy and faily inexpensive fix for ya. But also this would be a good time for an inj. upgrade if you so desired. Good Luck

 

Pintle hung, only the 160hp and 175hp pumps have copper sealing washers under the delivery valves.

 

Great to know thanks Don.

 

Has anyone had any experience with the Pensacola diesel 100HP injectors?? A stock injector is 45$, but I would like to upgrade if the 100hp injectors are worth it. Thanks

 

Well I splurged and got the stage 2 injectors from Pensacola Injection.

I am pleased with them although not Bosch they seem to be a quality injector for the $$$. Put them in and immediatly noticed lower EGT by about 100*-150* and the stock turbo spools much quicker. I have a feeling i will be sliding the fuel plate all the way forward.

Now I do have to fix the wastegate (its stuck) cause it will run the boost gauge past the rivet on the face, its only a 35lb gauge. IMHO if you are looking for an inexpensive upgrade they are worth it.