DANG THIS HARD STARTING!- Please Help
02-19-2004, 09:01 AM
#61
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I spoke with the dealer on the phone and he says there IS no check valve on the LP. Moreover, since my FP doesn't bleed off instantly, he says it's likely there's nothing wrong with the fuel delivery. His suggestion?
The injector connector tubes. He says they have seen cases where the injector tubes aren't quite seated right and allow air back into the system.
My question is this: IF the injector tubes have a small leak in them, wouldn't I be seeing diesel in the crankcase?? If the leak is big enough to let in air under atmospheric pressure, wouldn't it be big enough to let OUT diesel fuel at 24000 PSI??? The connector tubes leaking seems plausible enough if I could get this one question answered.
I don't quite feel comfortable taking it to the dealer yet, because I am NOT sure that the leak isn't my doing (i.e., max flow install, FFC, what have you).
The real wrinkle in all this is that the truck started this after sitting for 10 days in cold weather. That batch of fuel had previously been trouble-free for 200 miles. And this was before the Max flow install.
So if the problem was there with the stock parts before, how could it be blamed on my max-flow install?
The injector connector tubes. He says they have seen cases where the injector tubes aren't quite seated right and allow air back into the system.
My question is this: IF the injector tubes have a small leak in them, wouldn't I be seeing diesel in the crankcase?? If the leak is big enough to let in air under atmospheric pressure, wouldn't it be big enough to let OUT diesel fuel at 24000 PSI??? The connector tubes leaking seems plausible enough if I could get this one question answered.
I don't quite feel comfortable taking it to the dealer yet, because I am NOT sure that the leak isn't my doing (i.e., max flow install, FFC, what have you).
The real wrinkle in all this is that the truck started this after sitting for 10 days in cold weather. That batch of fuel had previously been trouble-free for 200 miles. And this was before the Max flow install.
So if the problem was there with the stock parts before, how could it be blamed on my max-flow install?
02-19-2004, 09:14 AM
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Do you still have your stock injectors?
If so, have you tried putting them back in to see if the problem is still there? I am no injector guru, but this will rule them out as a possible culprit.
If so, have you tried putting them back in to see if the problem is still there? I am no injector guru, but this will rule them out as a possible culprit.
02-19-2004, 09:20 AM
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Originally posted by HOHN
I suppose my LP COULD be to blame. I would hate to replace a pump that puts out such good pressure.
What is everyone's FP when the intake heaters are on? My FP barely registers at all. Then I crank it a little, and the LP kicks on and my FP goes to 18-20. I let it run a little while then I crank it over and it starts.
But it will never start on the first crank, when the LP is in the "startup" mode and the FP is low.
If the truck has only been sitting briefly, the FP will spike to 10 or so then hold 5psi at startup. It starts on the first crank in those cases.
This all seems to point to the LP allowing pressure to bleed off and then the whole system has to reprime if its been sitting for any length of time.
Maybe it's time for a trip to the dealer to get a new LP under warranty...
Justin
I suppose my LP COULD be to blame. I would hate to replace a pump that puts out such good pressure.
What is everyone's FP when the intake heaters are on? My FP barely registers at all. Then I crank it a little, and the LP kicks on and my FP goes to 18-20. I let it run a little while then I crank it over and it starts.
But it will never start on the first crank, when the LP is in the "startup" mode and the FP is low.
If the truck has only been sitting briefly, the FP will spike to 10 or so then hold 5psi at startup. It starts on the first crank in those cases.
This all seems to point to the LP allowing pressure to bleed off and then the whole system has to reprime if its been sitting for any length of time.
Maybe it's time for a trip to the dealer to get a new LP under warranty...
Justin
This is how mine works:
I turn the key to the start posistion. I can hear the LP running. It pegs my gauge to 15, and the LP shuts off (as if it is programmed to do this). The pressure falls to zero. (temp.does not affect this) It starts right up after the wait to start light goes off.
02-19-2004, 05:32 PM
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Ok, Justin. I thought of one more thing you could do to see if you are getting air in.
Take the return line off (maybe at the tank if you can get some slack)and place the the end of the line submerged in a container with some fuel in it. Run the truck. If you can see bubbles coming out of the line, then you are getting air in.
I've seen that procedure in a Cummins shop manual before.
Boyd.
Take the return line off (maybe at the tank if you can get some slack)and place the the end of the line submerged in a container with some fuel in it. Run the truck. If you can see bubbles coming out of the line, then you are getting air in.
I've seen that procedure in a Cummins shop manual before.
Boyd.
02-20-2004, 10:16 AM
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That's a good idea, Boyd. I think I will have to try that one. Thanks.
One thing I noticed this morning. Not only do I have a hissing sound at shutdown (sounds like a rattlesnake that's angry), but I have diesel fuel on the frame rail near the tank.
It's a wet spot that runs about 2 feet of the driver's side frame rail right behind the rear wheel.
I think I have a leak somewhere in the plumbing at the tank. Maybe time for a dealer visit?
Justin
One thing I noticed this morning. Not only do I have a hissing sound at shutdown (sounds like a rattlesnake that's angry), but I have diesel fuel on the frame rail near the tank.
It's a wet spot that runs about 2 feet of the driver's side frame rail right behind the rear wheel.
I think I have a leak somewhere in the plumbing at the tank. Maybe time for a dealer visit?
Justin
02-20-2004, 10:53 AM
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That was in a NT-855 shop manual, but it should still apply.
This problem must be getting on your last nerve by now. I hope you find the trouble soon.
Good luck.
Boyd.
This problem must be getting on your last nerve by now. I hope you find the trouble soon.
Good luck.
Boyd.
02-20-2004, 11:00 AM
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I find myself having to find new nerves just to make more that this problem can annoy
Overall, it's pretty minor. But I don't like having to ALWAYS start my truck with a custom routine:
1) bump starter to activate LP at full pressure
2)let pump run for about 10 seconds
3) crank it until it starts
The only way I can start it normally is if it's only been shutdown for less than 10 minutes or so.
My Red Ram goes to the dealer on Monday AM. I will report back what I find.
Overall, it's pretty minor. But I don't like having to ALWAYS start my truck with a custom routine:
1) bump starter to activate LP at full pressure
2)let pump run for about 10 seconds
3) crank it until it starts
The only way I can start it normally is if it's only been shutdown for less than 10 minutes or so.
My Red Ram goes to the dealer on Monday AM. I will report back what I find.
03-02-2004, 04:57 PM
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Dealer still hasn't gotten to see it yet. Their diesel techs are only there during certain days and I have had one conflict after another force me to reschedule.
I am going to pull the valvecover and check the injector holddowns. Someone said that it's possible for the copper washers to have a small leak and that will mean air in the return line. It's a stretch to me, but it's an easy one to check. So that's what I am going to do.
Justin
I am going to pull the valvecover and check the injector holddowns. Someone said that it's possible for the copper washers to have a small leak and that will mean air in the return line. It's a stretch to me, but it's an easy one to check. So that's what I am going to do.
Justin
03-09-2004, 01:46 PM
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Well, the mystery continues.
Today the hard starting just up and left. Gone. Adios. Ciao.
When I shut it down, there's no hissing at the tank, either. It seems that the hard starting and the hissing from the tank accompany each other. No hissing, no problem and vice versa.
I never did take it to the dealer. I am glad I didn't have to take it there-- exposing the BOMBs to the dealer any more than necessary isn't wise, IMHO.
A few days ago I pulled the valve cover and tightened the injector hold downs. Not a single one was loose, most were almost TOO tight imho. So I just loosened them and retightened.
There was no immediately noticeable difference after doing this. I still had to do my starter-bump dance to get it to start (which it always did).
Now out of the clear blue sky, the hissing is gone and so is the starting issue.
At least, that was the case over lunch.
We'll let it sit overnight to see if this is a glitch or if it really went away.
Justin
Today the hard starting just up and left. Gone. Adios. Ciao.
When I shut it down, there's no hissing at the tank, either. It seems that the hard starting and the hissing from the tank accompany each other. No hissing, no problem and vice versa.
I never did take it to the dealer. I am glad I didn't have to take it there-- exposing the BOMBs to the dealer any more than necessary isn't wise, IMHO.
A few days ago I pulled the valve cover and tightened the injector hold downs. Not a single one was loose, most were almost TOO tight imho. So I just loosened them and retightened.
There was no immediately noticeable difference after doing this. I still had to do my starter-bump dance to get it to start (which it always did).
Now out of the clear blue sky, the hissing is gone and so is the starting issue.
At least, that was the case over lunch.
We'll let it sit overnight to see if this is a glitch or if it really went away.
Justin
04-20-2004, 05:22 PM
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The hard starting is back, but only on a part-time basis.
It was gone completely until we had another cold snap. Now it's back. It's only there when it's been sitting a long time now.
There is no hissing from the tank.
When the weather's warm, the starting problem is gone. It seems only to do it when it's making a cold start after sitting a while.
It also seems to be more of a factor when it's parked nose-high instead of nose-low.
Looks like I'm going to have to recheck/re-torque all my fuel lines and fittings again.
My FP gauge is acting differently. Instead of shooting up to 15-17psi after it starts, it seems to crawl up to it. Almost like it's having to fight a clogged filter. Same thing when I get into the pedal and then let off-- the FP recovers more slowly than it did before.
Maybe time for another Fuel filter change, but it's only been 3K miles.
Is it possible that an air leak would cause the slowed FP recovery? There aren't any kinks in the supply side that I can see.
Justin
It was gone completely until we had another cold snap. Now it's back. It's only there when it's been sitting a long time now.
There is no hissing from the tank.
When the weather's warm, the starting problem is gone. It seems only to do it when it's making a cold start after sitting a while.
It also seems to be more of a factor when it's parked nose-high instead of nose-low.
Looks like I'm going to have to recheck/re-torque all my fuel lines and fittings again.
My FP gauge is acting differently. Instead of shooting up to 15-17psi after it starts, it seems to crawl up to it. Almost like it's having to fight a clogged filter. Same thing when I get into the pedal and then let off-- the FP recovers more slowly than it did before.
Maybe time for another Fuel filter change, but it's only been 3K miles.
Is it possible that an air leak would cause the slowed FP recovery? There aren't any kinks in the supply side that I can see.
Justin
04-20-2004, 11:05 PM
#75
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Am curious if you have tried a relay to feed power to your lift pump instead of being powered off the ecm circuit.
Was just thinking what do cooler weather, and sitting for awhile have in common. They both lower the volts in the batts, especially if your grid & fuel heaters kick in.
Was just a thought... I do remember reading more than one post indicating a relay solved a hard start condition due to low voltage.
Either way, it is a good thing to run a relay. Might just use a toggle switch for a temp test.
The thing that makes it hard to believe it is electrical, is the hissing noise from the tank.
It is possible there are 2 issues going on here, making it hard to diagnose.
Was just thinking what do cooler weather, and sitting for awhile have in common. They both lower the volts in the batts, especially if your grid & fuel heaters kick in.
Was just a thought... I do remember reading more than one post indicating a relay solved a hard start condition due to low voltage.
Either way, it is a good thing to run a relay. Might just use a toggle switch for a temp test.
The thing that makes it hard to believe it is electrical, is the hissing noise from the tank.
It is possible there are 2 issues going on here, making it hard to diagnose.