use a cheapie cause you wont get much use after...50 at idle...i think 30 to start...

have you had the hpop off? is it upgaded or anything? this is important for the res draining down! check the oil for fuel since you just did inj...did you do inj cups?

 

I have not had the HPOP off and I am pretty sure it is original. I did not do the injector cups. Cleaned them as best I could but did not replace.

 

ok,I battled a drain back issue that had been caused LONG ago and several owners later I fixed it...after getting my butt kicked for a few weeks by it.

how much have you added to the resivour anyway? one qt would not show much change on the dipstick. 3 would. how far was the dipstick level up?
Just trying to diferentiate between what has been added and possible fuel in the crankcase raising the level.

is it the stock fuel pump system??? you never said I dont think

 

As far as I know/can tell, everything is stock except for what I have just done to it. Bought it March 2012; crapped out on my first trip hauling my Jeep and it has been sitting in my driveway until this Dec.

I checked the HPOP after the first run after installing the new injectors. I think I added about a half quart that time. When I checked the oil it looked like it was almost 2 quarts over. I drained a quart at that time. I have added to the HPOP twice since then but no more than a quart total. I checked the oil today after adding to the HPOP and it was approx. a quart over.

 

I believe you have just found the problem. smell the oil. I bet its full of fuel.

either cut o-ring or bad inj cup...but dont take my word...that is where I would be looking IF it were mine.

I am going on a limb and throw out... the cup when hot the crack opens up and lets fuel pressure drop.when cold it closes enough to let fuel pressure climb and it runs until you shut it off...anyone??? I hope IM wrong.

 

A cup would be mixing fuel and coolant. My guess is the oil smells like diesel and you've got some o-ring issues.

The good news is, the valve covers seem to come off quicker the more times you done it.

 

Well drove it again today. Checked the HPOP and the level was just about where I left it Saturday. Oil showed about a quart high; (same), but again it was sitting on a slope. Started it up and it smoked quite a bit until about 10 - 15 miles, then the smoke cleared up completely. Drove it about 25 miles and ran fine the whole time. It does tend to stall at low rpm especially when backing/turning. Idles at 500-600 according to the tach.

After 25 miles or so, stopped and let it sit for about 20-30 minutes. Then, same thing.........no start and loud knocking. When it stalls, you can start it right back up but after it sits for more than 10 minutes or so, no start. Also found the valley filled with fuel. Cannot detect where the fuel is coming from.

This just keeps getting better! I had to leave it and will go back tomorrow to get it. If things hold true to form, it will start when I try it tomorrow and I will be able to drive home again???

 

I forgot to mention, there wasn't any smell or evidence of fuel in the oil at all. So, I got that going for me!

 

Well,THats great.Check fuel pressure?

 

Couldn't check it yesterday. Borrowed a fuel pressure gauge but could not hook it up as the engine lift bracket was in the way and the hose on the gauge was too stiff to make the bend. Need to remove the bracket or get a 90 degree adapter.

 

OK, so I grew tired and frustrated trying to figure it out and just didn't have enough time to work on it so I had it towed to a local shop with very good rep.

Got the call I didn't want while on vacation this Friday. Guy says it has 3 cylinders with bad/low compression and he suspects the cylinders are scorched. Says I am looking at approx. $6K for a rebuild and doesn't recommend a used engine. Problem is I am too far in debt on this truck already and a used engine looks like the cheapest/quickest solution.

Question is, what years of the 7.3 will swap into my 1996? What should I look out for when buying a used 7.3?

As always, thanks for your time and help!

Tom

 

Okay, so I took the truck to a second shop and I just got a call from the guy. He says he thinks the injectors are leaking internally. Says when he disconnects power to the injectors they are all still leaking oil out of the "spill tubes" and they should not be? He said some are worse than others but they all pretty much appear to be leaking. I asked him if it could have been something I did when I installed them and he said that he didn't think so as leaking the way they are would indicate an internal problem with the injectors.

I asked him how this would relate to the starting problem after the truck is hot and sits for 15-20 minutes and he said he thinks it is because when the oil is hot and leaking more there is not enough pressure being built up to open the injectors.

These injectors were purchased from Swamps last year and installed this past Dec. They only have maybe 120 miles on them at best? I do not know as much about diesels as I do gas and less about the inner workings of injectors. Any help, opinions, advice would be greatly appreciated!! I want to at least have a general idea of what I am talking about when I call Swamps.

Thanks,
Tom

 

I really think you need to slow down here before you start worrying about a new motor. These trucks are difficult at times to troubleshoot, and if you are not familiar with them they can send you in the wrong direction, just like your motor toast mechanic.... First off I would pop your valve covers and inspect your o rings and reseat the injectors, properly retorque. While you have them out INSPECT THE VALVE CUPS! make sure you are clear in that department as well. Also inspect your under valve cover harness and valver cover gasket/w plugs.

It sounds like you could have an injector seat issue, or o rings, which would cause the low compression.

The knocking you are hearing typically is attributed to fuel issues. A weak pump starving out, low fuel tank, improper fuel feed and oil feed in the heads, or even burnt up UVCH. It takes 2 seconds to pop your hood and get fuel pressure off the bowl... should be the first thing you did and I typically see 50-55psi at idle. Then pop your valve covers off and inspect your injectors. You need to make sure you are not making oil with coolant or fuel.

The fact you had a smoky startup after your first couple of runs sounds like to me you could also have oil pushing past your O rings. Residual oil was burnt and gone after 5 miles hard on the pedal on all the trucks I service.

I really have not heard of injector leaking oil after the motr shuts down. They may drip the residual out momentarly but they are not bleeding down rail pressure quickly.

If your HPOP is draining back you would know, 1-1.5" is not your problem.

 

The second shop's explanation sounds reasonable. It's unusual to have so many be wrong at once, but since you bought a set, it's possible you got a bad batch.

The first thing to do is call Swamps and get their opinion of the diagnosis and see if they would like any additional testing done, or if they want you to send them in so they can test them.

Of course if it's not a warranty item, I'd think about talking to a different injector builder about getting them fixed. Injectors aren't supposed to spit or leak oil if they are disconnected or if they are not being fired by the IDM.