At wits end

[wmoguy]

I am at my wits end with this damn truck. It's a love hate relationship. I'd love to finish off the build on this truck, but I've about had it with the "issues" this damn thing seems to have every week...

Latest is the starting issues. It SUCKS to start if the motor isn't hot. I have Brand new Beru's in it, along w/ a brand new fuel filter, manual Glow Plugs that are getting proper amperage. It also has a brand new fuel return line kit on it.
If the truck has been running and warm, it starts like a champ, barely a flick of the key.
If it's been sitting more than 4-5 hours expect to crank on it for a good 20 seconds and HOPE it starts.
I can't handle it! If I can't figure it out soon, the truck goes bye-bye.

Just now for the very first time, when the truck was at the shop to get the turbo installed, it flat wouldn't start. We had to put ether on it to start the damn thing! So now prior to installing the Turbo we got to figure out EXACTLY why it's hard starting (or now no starting)
Ideas????? Injectors? Injection Pump? The fuel pump itself is fine. When cranking on it if you tap the schrader valve it spews fuel just fine. Also, it's not my WMO mix. The issue can be had on my front tank which is straight Diesel (and had been purged for a good 10 mins on last run)

I need idea's fellow IDI'ers. I am literally one short decision away from selling this damn thing and never owning one again.

 

[bike-maker]

Mine's been having the same exact symptoms. Mine has always started though..............just takes a while.
It started when I put a load of 50% WMO in it. Since it wouldn't cold start without fogging the neighborhood, I switched back to straight #2, and it has been getting slightly better ever since; but I still have to crank it for about 15-20 seconds until it lights.
I'm thinking I have a small leak somewhere, which is sucking air. I'm wiring up an electric fuel pump this weekend, maybe that will help with the diagnosis

 

[Agnem]

Crankspeed, fuel, air, timing, heat. These 5 things need to be right in order to get it to start. You can verify the crank speed with an external tachometer. Air is pretty much a given. Fuel you can verify by cracking an injector line and holding the pump at full throttle while you crank. You should also see white smoke at the exhaust. Drop your Y pipe to make it easy to see. Timing and heat tend to be the two hardest to verify.

 

[7.3 powerstrok]

sounds like motor has low compression ?check screen in ip pump?

 

[wmoguy]

sounds like motor has low compression ?check screen in ip pump?

oh yea forgot to add it had a compression check about 60 days ago, all good there.

Whats the check screen in the IP?

 

[7.3 powerstrok]

there is a fuel screen in the injector pump .could be cloged .if compression is fine ,then i"ll bet the injector pump going going gone ,my truck had very similar problems and after a lot of troubleshooting found the injector pump was the problem .......if the injector pump is gone truck may start at times with no problem ,only to run several miles then die ...sometimes lots of smoke chugging ,,then run perfect again ,im telling you that the standine injector pumps in these engines 6.9-7.3 were not desinged to be throttled all the time thats why after they have more than 75,000 miles they can quit at any time ...

 

[wmoguy]

there is a fuel screen in the injector pump .could be cloged .if compression is fine ,then i"ll bet the injector pump going going gone ,my truck had very similar problems and after a lot of troubleshooting found the injector pump was the problem .......if the injector pump is gone truck may start at times with no problem ,only to run several miles then die ...sometimes lots of smoke chugging ,,then run perfect again ,im telling you that the standine injector pumps in these engines 6.9-7.3 were not desinged to be throttled all the time thats why after they have more than 75,000 miles they can quit at any time ...

good to know. I'll order a pump instantly if that is what it can be diagnosed down to. I've thrown so much freakin money at this truck its not even funny.
Hows the simplest way to determine if the injection pump itself is suspect?

 

[7.3 powerstrok]

oh yea but the injector pump usually does not completely fail ,it will just play the stop -go-start -no start ...run-good-run -bad smoke no-smoke -game until you say ok its gotta be the injector pump

 

[wmoguy]

forgot to add, this truck DOES NOT SMOKE going down the road. I mean you can lug it all you want and it won't smoke at all. If I try really hard, and start in 2nd and drop the clutch it'll give me just a tiny puff. Other than that, no smoke.
I've always thought that to be suspect.

Again, the truck starts ALWAYS starts like a champ when the motor is warm. Cold starts it's always 2 cycles of the GP's (10 seconds each) and it comes to life with a ********* puff of smoke, then all is good. I always thought if the IP was going out, warm starts usually is what would go first?

I've never had the truck chug, or die on me when it's running. it runs pretty well for a currently N/A truck.

 

[7.3 powerstrok]

oh yea forgot to add it had a compression check about 60 days ago, all good there.

Whats the check screen in the IP?

the two tell tail sign of a bad injector pump is remove the top cover and view tiny broken up bits of black plastic( nylon)or confirmed milege is 75,000 or more

 

[7.3 powerstrok]

check the sylinoid in the cover on the pump they usualy outlast the pump but its possible its malfuncitioning.

 

[wmoguy]

check the sylinoid in the cover on the pump they usualy outlast the pump but its possible its malfuncitioning.

k will do on both items. Thank you

What else should I be diagnosing if thats not it everyone?

It sat and idled for a good 20 mins at the exhaust shop it's at right now. Then they had to move it out of the shop for a while. It started right up. WTH????? It's definetely a cold start issue, not a warm start issue.

P.S. Anyone have a Moose Pump laying around they want to send my way if it's the IP? I don't have time to ship mine off and wait for it to come back.

 

[wmoguy]

Crankspeed, fuel, air, timing, heat. These 5 things need to be right in order to get it to start. You can verify the crank speed with an external tachometer. Air is pretty much a given. Fuel you can verify by cracking an injector line and holding the pump at full throttle while you crank. You should also see white smoke at the exhaust. Drop your Y pipe to make it easy to see. Timing and heat tend to be the two hardest to verify.

If it cold starts poorly, but warm starts excellent, could that be a timing issue?

 

[itsacrazyasian]

First off make sure you are getting power to the glow plugs and make sure they are getting hot. Just because they are new and beru's doesnt mean they are functional.

2nd i really feel that you have a air leak somewhere and the system is bleeding down after it sits. If you can't find the bleed down, toss an inexpensive electric fuel pump and bypass the mechanical pump for now (leave it in, just slide some hose from the hard line onto the filter head line so you don't modify anything) and wire in the eletric pump to run with the igntion on. Let it run for a few seconds while you wait for the glow plugs, should pump fuel back into the motor.

 

[GOOSE]

I would look into your pump as well. I forget the technical name but as the pump wears the tolerences get sloppy. when this happens, heat is no longer transferred uniformly. This causes hot starts to be a PITA. Thermal.... something or other. Somebody help me here.