Archived trouble starting when motor is at operating temperature

[av3fire]

My "Problem" has escalated to now have me very concerned.

it started a couple months ago where it would occasionally not stay running after turning the key when the motor was at operating temp.
not all the time, just ever once and again

NOW it seems that once it gets to operating temp, the only way i can get it to run is to depress the throttle half way or more while turning the key.
it starts and stays running.

it seems to start normally when cold.

when warm, if I turn the key it does fire off, but immediately shuts down and will do this as many times as i turn the key (tried it once to see if it was just a once or couple times thing and it did it for 8 times until i depressed the throttle and then it stayed running)

motor is a '94 12 valve with a cold air intake and open exhaust. all other parts are still stock. I have adjusted the fuel plate and afc just a little, but only to find the sweet spot in lighting the turbo. Do not run it too hard (do not tow daily) and try to keep the boost under 30 lbs.


any ideas??? I am thinking it may be in the p-pump..... maybe needs more lube added to the fuel? I had not been doing this on a regular basis until the past month

thanx for your input

 

[GAmes]

motor is a '94 12 valve with a cold air intake and open exhaust. all other parts are still stock. I have adjusted the fuel plate and afc just a little, but only to find the sweet spot in lighting the turbo. Do not run it too hard (do not tow daily) and try to keep the boost under 30 lbs.


any ideas??? I am thinking it may be in the p-pump..... maybe needs more lube added to the fuel? I had not been doing this on a regular basis until the past month

Your p-pump is probably a good diagnosis. The early ones have a problem of delivery valve warpage that manifests itself when the pump gets hot and causes problems. You can troubleshoot it by pouring some ice water over it when the engine starts stumbling. If it smooths out it is repair or replacement time. Forget about fuel "lube" because it is totally unneeded, in yours and every other diesel. The myth about ULSD being low in lubricity was started by the snake oil makers and stays alive because of the gullible. I'm still running the original p-pump in mine, the only time it gets a fuel additive is in the dead of winter, and that is only if I buy fuel in the south and am going way north.

 

[cerberusiam]

Once it gets started can you lift off the throttle and it stays running? Never a problem cold but always warm? Have you check LP pressure and fuel delivery once it is warmed up?

DV's may be compromised or even the barrels, hard telling exactly what without more testing and probably disassembly.

While the main body of the p-pump doesn't need fuel for lube the rest of it does and it will be impacted by fuel quality. Not as much as the pumps that rely on fuel for internal lube but enough additives are recommended. Ignoring the fact ULSD is lacking lubrication properties of LSD or older fuel is just head-in-the sand tactics, every single chemical analysis of the fuel has proved that beyond a doubt. The other pumps rely heavily on fuel for internal lube and they don't like when it is lacking

The pump is 23 years old, if you have never had it refreshed it is way over due, aside from the miles. Might as well pull the injectors and have them replaced also, the whole system is likely overdue for maintenance.

 

[GAmes]

...... every single chemical analysis of the fuel has proved that beyond a doubt. The other pumps rely heavily on fuel for internal lube and they don't like when it is lacking

The pump is 23 years old, if you have never had it refreshed it is way over due, aside from the miles. Might as well pull the injectors and have them replaced also, the whole system is likely overdue for maintenance.

Really? Care to link just one? How about some scientific evidence that injection pumps that are lubed and cooled entirely by fuel need an additive. Not just the BS anecdotal crap found on the web, real studies. Oh, that's right, you have that one from California, the one that was written 10 years before ULSD ever was pumped.:-laf

My pump is 20 years old, never had a fuel lubed part replaced. 12 valve injectors are good for 400+k miles. Millions of diesel engines, old and new operate just fine without snake oil. Check the trash cans at a truck stop. You won't find them full of additive bottles because truckers know additives aren't needed. Come to think about it, there are seldom any snake oil bottles in the trash cans of the auto pump lanes either.

 

[cerberusiam]

Nah, removing the sulphur from diesel didn't break the long chain molecules that provide the "lube" in diesel. Nah, the extra refining didn't dry out the fuel more than it was originally, just like the refining for gasoline doesn't remove lubricants. Nah, bio-diesel doesn't provide more lubrication that dino oil and is recommended for extra lube properties by every diesel engine manufacturer. Nah, Cummins and Bosch don't have a fuel spec that details lube properties of adequate fuel. It is all a big conspiracy that the fuel suppliers are attempting to add lube back with additives put directly into tankers at the pipe line ends.

Let me google that for you really quick for just ONE of hundreds of independent tests done when ULSD was mandated: https://www.ag.ndsu.edu/news/newsre...a-low-sulfur-diesel-fuel-affects-lubrication/.

Just because a 12V injector will operate for over 400k doesn't mean it is doing it correctly, same with the pumps. Most of us subscribe to a bit tighter spec on maintenance than "run it into the ground". You should familiarize yourself with Cummins specs on injectors and injection pumps AND the reasons for the recs.

 

[GAmes]

No where in that article does it state that the lubricity agents that are stripped by reducing sulfur aren't added back to the fuel after refining, nor does it state anywhere that the fuel we buy has less lubricity than the highly poisonous sulfur rich fuel of the past. If you had paid attention you would have realized it is basically an article promoting bio-diesel. In addition, you won't find a legitimate article that does state that ULSD at the pump doesn't meet ASTM standards. I never said, or even hinted, that bio-fuels do not have lubricity qualities. You love those red herrings don't you. So, once again, you are unable to provide any proof to the ULSD low lubricity myth.

Exactly how do you figure I am running my engine into the ground? If it performs well, doesn't smoke and gets excellent mileage I'm pretty sure it is being maintained pretty well. I consistently get 20-22 mpg empty on the highway and towing mileage is as good as it was when the truck was brand new. I have no qualms about going anywhere, summer or winter. Unlike a lot of people, I don't need to buy a new truck every few years because I can't depend on mine to get me where I want to go. Maybe it is because I don't abuse it by pouring strange brews into the fuel tank? I had my original injectors pop tested after I replaced them out of curiosity. They had over 400k on them and were within spec. The only thing wrong with them was the holes had enlarged due to the thousands of gallons of fuel that had been forced through them which affected my mileage. They worked very well in another engine that had been modified more than mine.

Face it, you are only parroting the inaccurate drivel spouted by those who don't have a clue.

Getting back to the OP. The fact that it starts and runs well when cold means the rest of the fuel system is in good shape. Try the ice water trick and let us know what happens.

 

[mfurrh55]

I think y'all scared him off

 

[cerberusiam]

Possibly. Too much tin foil, paranoia, and voodoo instructions can be a bit daunting.

He has some things to investigate and assess, takes time to run thru the possibilities.

 

[Missouri Mule]

Your symptoms seem to point to a bad starter (or starter going bad). Only symptom that doesn't fit is that it will fire up but die if you don't push the go pedal down.

No start symptoms if won't turn over in the morning battery if it start after you driven it for a while starter.
A symptom that the starter is on the way out that you have to depress the go pedal to get the engine running (mostly after you been driving a while turning it off and restarting.)
Both napa piece of junk life starters did that to me ( had to push the go pedal to get the engine to turn over (especially when I'm at the produce market) Lucky for me the first piece of junk died in my driveway (3 yrs old) the 2nd piece of junk died at my business (2yrs) My original starter last aprox. 15-16 yrs. I had another shop put on a reman Denso (I counting on this one to last more twice as long than the 2 from napa).
Mule 366,Plus and counting original injectors ( injectors holes probably bored out nicely) pump is doing just fine.

 

[MichaelOverfield]

Really? Care to link just one? How about some scientific evidence that injection pumps that are lubed and cooled entirely by fuel need an additive. Not just the BS anecdotal crap found on the web, real studies. Oh, that's right, you have that one from California, the one that was written 10 years before ULSD ever was pumped.:-laf

My pump is 20 years old, never had a fuel lubed part replaced. 12 valve injectors are good for 400+k miles. Millions of diesel engines, old and new operate just fine without snake oil. Check the trash cans at a truck stop. You won't find them full of additive bottles because truckers know additives aren't needed. Come to think about it, there are seldom any snake oil bottles in the trash cans of the auto pump lanes either.

Those idiots at Bosch need to listen to you, apparently they put special coatings on their HPFPs due to US ULSD. What a waste, apparently.

https://www.google.com/url?sa=t&sou...ggsMAA&usg=AFQjCNH7osbECJSDpMmUsFXghEomeR9-fQ

 

[MichaelOverfield]

No where in that article does it state that the lubricity agents that are stripped by reducing sulfur aren't added back to the fuel after refining, nor does it state anywhere that the fuel we buy has less lubricity than the highly poisonous sulfur rich fuel of the past. If you had paid attention you would have realized it is basically an article promoting bio-diesel. In addition, you won't find a legitimate article that does state that ULSD at the pump doesn't meet ASTM standards. I never said, or even hinted, that bio-fuels do not have lubricity qualities. You love those red herrings don't you. So, once again, you are unable to provide any proof to the ULSD low lubricity myth.

Exactly how do you figure I am running my engine into the ground? If it performs well, doesn't smoke and gets excellent mileage I'm pretty sure it is being maintained pretty well. I consistently get 20-22 mpg empty on the highway and towing mileage is as good as it was when the truck was brand new. I have no qualms about going anywhere, summer or winter. Unlike a lot of people, I don't need to buy a new truck every few years because I can't depend on mine to get me where I want to go. Maybe it is because I don't abuse it by pouring strange brews into the fuel tank? I had my original injectors pop tested after I replaced them out of curiosity. They had over 400k on them and were within spec. The only thing wrong with them was the holes had enlarged due to the thousands of gallons of fuel that had been forced through them which affected my mileage. They worked very well in another engine that had been modified more than mine.

Face it, you are only parroting the inaccurate drivel spouted by those who don't have a clue.

Getting back to the OP. The fact that it starts and runs well when cold means the rest of the fuel system is in good shape. Try the ice water trick and let us know what happens.

Also, the VW debacle was more than the Emmisions cheat. They used those Bosch HPFP with Cam roller design, coated to resist wear due to ULSD. When they started to come apart,VW blamed customers putting gas in the tank. The NHTSA report showed that was not the issue. The distribution of diesel includes additives for lubricity, if done consistently and correctly, no worries.. problem is, it's not a guarantee it is being done consistently and correctly. Additives are cheap insurance for those times. If the "snake oil" guys were just in for profit, they would not sell a Gallon jug that treats 2250 gallons of fuel. (Optilube summer blend). My prior VW did show early signs of a HPFP going with metal in the fuel filter.. that is why I got rid of it. The crank piston pump like the CP3 used for Cummins are far more robust, my Chevy Cruze Diesels have a similar 3 piston crank HPFP, all these are fuel lubricated, and cooled. Only the much larger big rig engines use separate engine oil to cool and lubricate the HPFP.

 

[MichaelOverfield]

http://fueloilnews.com/2010/03/04/taking-the-mystery-out-of-lubricity/

 

[GAmes]

http://fueloilnews.com/2010/03/04/taking-the-mystery-out-of-lubricity/

I'll try to read through the prior post's link a little later. But for now...........fail!


"Jerome P. Sava is a ChemE and partner at C&S Scientific Corp., Box 1056, Hightstown, NJ 08520; a company identified with R&D and marketing of new fuel technology and chemical treatment. "

 

[MichaelOverfield]

I'll try to read through the prior post's link a little later. But for now...........fail!


"Jerome P. Sava is a ChemE and partner at C&S Scientific Corp., Box 1056, Hightstown, NJ 08520; a company identified with R&D and marketing of new fuel technology and chemical treatment. "

Read the information from NHTSA.. Bosch has made changes to their pumps design due to low lubricity from ULSD. This is a company that worked with VW to cheat emmisions to save $300 per car, something tells me they are not going to waste money with costly design changes for a non issue... But, I'm only a Mechanical Engineer that works on problems like this all the time.. not everything is a conspiracy. It's not a secret that lubricity additives are being added by the distributers also, why? They like wasting money too? Odd.

 

[jhenderson]

Don't waste your time. Ames powers of deduction are lacking, too say the least.

 

[GAmes]

Don't waste your time. Ames powers of deduction are lacking, too say the least.

Says the guy who doesn't have the nerve to ask a weight official a question.

 

[cerberusiam]

http://fueloilnews.com/2010/03/04/taking-the-mystery-out-of-lubricity/

Just one of the hundreds of studies and tests done by independent facilities and commissioned by pretty much all the Diesel manufacturers. It was known issue 10-12 years ago and it hasn't changed in the interim, universally accepted by all the particulars involved.

Everybody got the memo, some just choose to ignore the content as being pertinent. I guess it is too much to ask that opinions obviously developed from truck stop dumpster diving to integrate corroborated scientific evidence to the contrary.

 

[jhenderson]

Says the guy who doesn't have the nerve to ask a weight official a question.

No , says the guy who can read. Seems as though I remember you being the one who claimed to be in the presence of God in the weigh station,but forgot to ask how much wt. you could put on his rear axle before he got in trouble. Cerbs got you pegged.

 

[GAmes]

Those idiots at Bosch need to listen to you, apparently they put special coatings on their HPFPs due to US ULSD. What a waste, apparently.

https://www.google.com/url?sa=t&sou...ggsMAA&usg=AFQjCNH7osbECJSDpMmUsFXghEomeR9-fQ

Where to start? The paper is about model year diesels that were (unless they were all from CA) on the road prior to the complete change over to ULSD. As a result, there is no direct link to ULSD causing any of the failures, proven by the fact there is not ONE reference to ULSD fuel other than the notation about the HPFP with Anti Wear Package (AWP). That one reference is your proof that ULSD lacks lubricity? Good thing you added the caveat "apparently", you apparently can't link the paper with ULSD low lubricity either.
Why did Bosch coat their plungers? Good question, you'll have to ask them. But since you seem to like to play 20 questions, here's some back. Why would Bosch coat their components with some unknown substance when the technology for producing metals that are impervious to low lubricity fuel has existed for over half a century? Why not manufacture the affected parts out of the same metal used in gas turbine engine fuel controls if low lubricity was a concern? In 100 flight hours a UH-1H goes through approx 900 gallons of Jet fuel, arguably a very low lubricity fuel. That is probably more fuel than an average diesel pickup owner goes through in a year, yet fuel controls last for hundreds of flight hours and don't fail.

Read the information from NHTSA

The National Highway Traffic Safety Administration? Give me a link.

It's not a secret that lubricity additives are being added by the distributers also, why? They like wasting money too? Odd.

Really? Here's a news flash, lubricity additives were added to LSD fuel too. The same pipelines that carry diesel also carry jet fuel. No additives needed or wanted in jet fuel.

Just like your predecessor you can't come up with credible proof that ULSD has less lubricity than LSD did. Jumping to conclusions based on a salesman's pitch or an innocuous notation in a paper than has nothing to do with ULSD is laughable.

Hey, if you want to dump money into your tank for no proven gain, be my guest. Just don't pee on my leg and tell me it's raining.

 

[GAmes]

Just one of the hundreds of studies and tests done by independent facilities and commissioned by pretty much all the Diesel manufacturers. It was known issue 10-12 years ago and it hasn't changed in the interim, universally accepted by all the particulars involved.

Everybody got the memo, some just choose to ignore the content as being pertinent. I guess it is too much to ask that opinions obviously developed from truck stop dumpster diving to integrate corroborated scientific evidence to the contrary.

That isn't a study. That is an article written by a marketing guy. Assuming you got past the 8th grade you should know that a study contains real data and references. It carries the same weight as your "facts", which is none.

Since there are "hundreds" of studies and tests why can't you post just ONE ?????????

If it is "universally accepted by all the particulars involved" why do so few diesel engine owners actually use additives? Trying to equate the fact that truck owners aren't filling trash cans with additive bottles to "dumpster diving" only serves to illustrate how little you are.

If ULSD is so bad and additives are "insurance" why hasn't our host printed an article showing the analysis of the "low lubricity" fuels taken from several different pumps? With the contacts some of the writers have there would surely be tangible evidence if lubricity was an issue.