Wrecked my injectors/HPOP...

[SMOKNZ]

Guys,

Looking for a little help on diagnosing a problem with my truck. I ran my truck low on oil (4 quarts) due to a slight leak from my rusty oil pan. I dont drive the truck much and knew enough to buy some oil for my trip last weekend but was too stupid to not check the oil... I was driving at 65 mph for about 2.5 hours and i slowed down because I was coming into a town when all of a sudden the idle became very erratic and the motor started loping real bad. I pulled into a gas station and checked everything, good fuel pressure, good oil pressure, good engine temp and EGT's. I immediately thought oil level and possible starvation of the HPOP. I was 4 quarts low and filled it up and restarted and it ran fine for about 3 blocks and just stopped dead. I was able to restart and it was doing the loping thing again and the SES light came on. A Ford dealer was 2 blocks away so I towed it there. They said it was a bank of injectors and wanted $2900 to start there with the impression that they may have to go further. I'm towing it home to do the work myself.

My initial thought was the HPOP died due to oil starvation and that the injectors couldn't function due to low oil pressure. It does start and run normal but will just die suddenly at idle and even at rpm. When it restarts it is loping real bad. Seems to me the injectors do function but just dont have the oil to work. If the HPOP did crap out would this put crap into the oil, and will an oil change get it all out.

I have plans to change the Pan, can this be done without pulling the engine? Also is there a guage to monitor the injector oil pressure? I remember seeing an electric one years back but cannot locate it anymore.

This is a 99 F350 early version with 360,000 miles on the odometer.

Sorry for the long post.

Bill

 

[BIG JOE]

At 335K, I'd say yer due for a set of Injectors And HPOP. And while yer at it..
New UVC harnesses. (and Glow plugs ? while yer in there ?)

I recently had the same basic symptoms, smoke at start-up, slight, occasional lope at idle. Changing out the Injectors, harness's (GP's)

I'm thinking New HPOP soon too ?



Joe

 

[Dogman]

If the HPOP did crap out the truck would not start and the problem would be a cross all the injectors. I would look at the injectors them self. Also check the wires harness to the injectors. The 7.3 have a chaffing/and shorting problems with the plugs.

 

[SMOKNZ]

I got word back from the dealer that the tech did some work to it and I might be able to "limp" it home 100 miles...

Sometimes it wouldn't start at all and when I say lope I mean that it wasn't slight it was huge!

Injectors were replaced just under 100K miles ago by the previous owner.

Can someone explain how oil gets to the HPOP reseviour? Is it supplied by a separate pump or is it the same one that supplies oil to all the engine bearings? Why does the HPOP starve when the engine oil is down a couple quarts?

Thanks

Bill

 

[BIG JOE]

The (separate) low pressure oil pump supplies oil for engine lubrication. The HPOP increases the low(er) pressure to "Pop" the injectors. If the HPOP lost part/most of it's prime, due to being 4 qts low on oil.. THAT, could be the cause of your issues.

I'm thinking the Tech re-primed the HPOP reservoir.. purging the air.. making it possible for you get it home.. for further troubleshooting.

If the HPOP is the Original pump.. with 335K on it, and only 100K on the Injectors.. you may just need to R&R the HPOP.. or at the very least (first).. run a Scan, and see if you get any Injector~HPOP pressure related codes.

Joe

It requires 500 HPOP psi minimum.. to pop the Injectors.. to start it.. and maintain an idle.

 

[DaveBen]

The other thing I that comes to me is; you don't know what injectors were used in the replacement. New or junk rebuilds?? You need to scan it to see what codes come up, like Joe said.

Dave

 

[dpantazis]

yes, the LPOP feeds the HPOP. if you are not pushing low pressure oil to the HPOP, same effect I would think.

2900 for new injectors sounds a 'bit' on the high side. get a second opinion.

as far as limping on the HPOP home, i dunno.

could you be suffering from a bad injector o-ring too?

 

[Dogman]

Or If the oil was that low it could have air in the system. It could clear up on the way home.

 

[DaveBen]

Two things you want to avoid; running out of fuel and running low on oil. These are basic needs for a diesel engine.

Dave

 

[Tbar]

Maybe just air in the system.........top it off with oil then drive it like you stole it. If it doesn't clear up in 30 miles of wide open throttle then think about other issues.


Tbar