I have had the injectors built and put in new o-rings of coarse and I am still getting fuel in the oil.Does anyone know what else could be wrong that could cause that?
Fuel pump shaft seal. Cracked or porous cylinder head. Dose it white smoke at idle ? if so check the AFC air line from the pump to the intake manifold for fuel in it. Had that trouble on my dozer. pulled the line off & noticed fuel in it. Best I could tell when the machine was at idle the pump was leaking fuel past the aniroid valve (AFC) and putting raw fuel in the intake causing some white smoke & putting a little fuel in the engine oil over time.
I fought and fought the same problem for a long time on one of my n-14's and it turned out to be that when the injector shop burnished the metering screw out they drilled too far and the drillbit exited the inj body and was in pumping fuel in the oil, sent the injectors to them twice and they tested good even bought a new STC box for it..... Yeah they never repaid me for my 5 oil changes, possible damage to motor, labor, or truck rental, STC box (bought it from them) or anything Not sure of the similarities of an ntc and a STC but a few of the possible culprits are on STC motor are. 1. STC box 2. "Macaroni" or "macaroni oring" 3. Head 4. Inj orings 5. Failed or FUBAR injector body lol Make sure the inj orings didn't get pinched or twisted when you installed them it can easily happen, I always use a little gun grease On an STC there is no way a fuel pump could cause this as there is a dry cavity between accessory drive and the pump itself fuel will just puke out the weep hole if front pump seal is shot and even that is rare
Thanks for the info fellows.I will take a look at some of the things you suggested and see what I can figure out.
I can tell you from bitter experience that if a dirt dauber makes a nest in that weep hole from very good clay, and then you run the engine and bake it into ceramics, the fuel won't come out. But, hopefully you don't have the kind of luck I do, and wouldn't disassemble a lot of stuff before finding it. :beatsme
I don't know what this engine is in but is there a tank above the engine or any way pressure can be in the fuel tank?
Hello, per my cummins book and years of 'spernce, I use clean motor oil on the injector O-rings, and I have seen the front seal on a PT-pump put fuel in the oil. it has a weephole yes, but it is possible , had a worn cam lobe on a BC-3 give a bad setting a cause a seep on the injector , got fuel in the base from that too. How are the injector bores in your heads , check them for scores and scratches , hope this helps.
Good god man wash the damn thing once in a while lol :tong
I don't know if you have dirt dauber wasps in the Midwest like we do here, but you can lay an air wrench down and go to lunch, come back and the air inlet will be plugged tight with hardened clay and wasp eggs. The right time of year there'll be 30 or 40 inside the shop at any moment, and just as many outside.
And you say you live in god's country...... he haw haw.
Thanks mitch504 but I pulled the pump first and it was not leaking,I also used clean grease on the o-rings when I installed the injectors,the original o-rings didn't look or feel bad but I replaced them,unless I pinched one I don't think they are leaking.Thebores in the head may be a posibility bot I didnt notice anything there.I am going to look at the AFC line that td25c suggested,by the way the engine is in a 81 International F2275 tandem tractor.
I was curious , is this why you changed injectors in the first place, if so you could have a bad or cracked injector body that slipped by the pump shop if they built yours and gave them back to you , it would be a bit+# but on a 2275 but if you pressured up the system with the engine static , you may could see something leaking to the inside with the valve covers of-------good luck with that on the center head ha-ha---- you may try using a porta power pump with a guage and checkvalve , if you do this use red fuel and or food coloring to help spot the leak. probably be best to have engine up to temp. for this. or plug in the block heater at least. p-s I cut my teeth on IHC fleetstars F-2000D's and F-2070A's so you probably don't have any hide left on your arms at this point ..........just an after thought......you don't have a restriction in the fuel return do you????
Yes GabbyVice27, Cummins dose list a procedure for checking the overhead for leaks using air. Cap off the return line & pressurize the system at the rear head fuel inlet using 30 psi. Then look for bubbles around the base of the injectors .
Ok folks,I'm going to go back to the advise I got on here last year when I first started trying this do it yourself approach and g look at the heads,especially the injector cups.Thanks for the input from everyone.