[Arizona Dave]

I have about 10K on my rebuilt engine. There are lots of new parts and old parts trying to work together. The truck runs really great, reliable starting is the issue. 10% of the time it starts faster than a gas car on a hot day, the rest of the time it's a mixed bag from long cranks to just not starting. It seems like the no starts are more of a warm engine issue. It has always started if left alone for 8 hours and runs great as soon as it starts, no rough running at all.

Replaced lots of parts ICP and harness, main harness, stand pipe, cam sensor, glow plugs, injectors, AD 2 in the rebuild. Re-used HPOP and (2nd) FICM and batteries.

Sangauge reads FICM 49V, ICP/HPOP 660 low idle and peaks around 1400+. No codes, not even with a 'no start'. It has good crankspeed and battery voltage when it turns over.

I'm getting tired of being picked up and then going back 8 hours later to retrieve my truck. Any thoughts?

 

[dannyboy950]

Have you noticed what your readings were at the time of the no start condition?
Have you tested for fuel pressure and flow? Have you tested for combution gas in the fuel system?

 

[Arizona Dave]

I haven't tested the fuel pressure from the AD 2, however it is a brand new replacement unit and filter. The HPOP readings are pretty consistent at all times as is the FICM, that's is what is puzzling. The truck RUNS better than it ever did new, it's all about the starting consistently at this time.

I will have someone test for combustion gas, I don't know how. Any other suggestions to have checked when I run it back in to have that tested?

 

[dannyboy950]

The combustion gas test I use is a down an dirty field test. Remove the fuel filter cap on top the motor. Top up with fuel till just below overflowing. Remove the FICM and fuel pump relays or fuses and have a helper roll the engine over a few times [no more than 15 sec at a time with a 15 sec rest between rolls] observe for bubbles in the filter houseing. If you have bubbles comeing from the line going to the heads, you have combustion gas.

Further isolation of the problem requires a little work. If your truck has independant lines going to the heads disconnect the banjo fitting 1 at a time and tie a small baloon over the banjo tie with seveal rubber bands or tiewrap. Roll the motor a few times again, if it is leaking gas it will inflate the baloon.
should your system have the y-pipe you will need 2 old banjo fittings cut off from some old lines leave about 6 in of line. Install the fittings an washers and secure baloons on each line. Repeat the roll over procedure. The baloon that inflates is the problem side.

Further isolation can be done by removeing 1 glow plug at a time unill the bubbles quit, that is your leak, before pulling that injector plug the glow plug back in and test any cylinders left in case there is more than 1. Rinse and repeat. LOL

 

[Young-SC-Owner]

Sounds like an HPO issue.

 

[southend]

Sounds like an HPO issue.

I agree with this.^^^ But may be hard to find a leak with just the air test, that is usually best for larger leaks. Of course it wouldnt hurt to check for combustion gases, easy enough. OP, update your sig, it would help.

Sent from my phone that somebody didn't help me get.

 

[dannyboy950]

At first I thought HP oil leak also but he has good startup pressure and the 1400+ reading would be low for WOT but not for half throttle and he really doesn't say the rpm.
Coupled with the fact of no codes I had to eliminate the hp system. If the icp was low for the rpm range he should get a code for [ICP within range but lower than expected]
beside I was answering his question about the test, haveing it done by someone when he could do it himself.

 

[Arizona Dave]

Thanks for the advice. The truck started all day today, until my wife's 4th errand. It's now sitting overnight at her doctors office parking lot. I just got home from work and haven't had time to go over and look at it. The 1400 PSI was noticed on a short rev up to about 3/4 throttle. No codes have been present either on my Scangauge or at the shop.

I run the Air Dog 2 unit on the fuel system. Have there any common issues with those and dry cranking? (I can hear it running).

The ICP and harness were replaced last week, thinking they could have been the issue, but it didn't help.

Again, this truck runs great from the second it fires over and appears to be a just slightly long crank when cold and a complete failure to fire 1 out of 4 times when warm. I'm guessing it fires up in the morning. I'm taking it to a guy with different diagnostic equipment tomorrow, but still would like to give him as many of your suggestions as possible, because of the lack of codes and having already replaced so many of the suspect parts. Thanks for further suggestions.

 

[Mike 2000 f250 7.3]

dummy plugs mine did the same thing

 

[Arizona Dave]

Thanks for the advice gentlemen, I passed it on. The truck has started great today of course, it is on it's best behavior knowing it's going to be checked by another mechanic.

 

[justintime_3]

Any update on what was causing this?

 

[Arizona Dave]

Any update on what was causing this?

Sorry for the delay, February was an incredibly busy month on too many fronts. After three mechanics checking and re-checking each others work and replacing suspect parts in the order of lowest to highest costs, a fitting on the HPOP was replaced. It was leaking slightly when it was warm, but not cold. I have too many acronyms that I work with on a daily basis. But I think it was the STC fitting. The truck starts very well, even on cold days.

Hopefully, this helps someone else. Two mechanics both recommended the entire HPOP be replaced. This fitting fix was only a few hundred.

The Scangauge still shows pressures up to around 4,000 on my HPOP.

 

[PSDMikeB]

You didn't say what year it is, but if it has the newer style HPOP, from what I have read here they are pretty reliable. Based on your pressure, it is still peforming well. If it were me, I would leave it since they are so expensive.

MikeB