strange hard starting issue
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From: Gardendale Al
I'd suggest that you take a look at the starter- the connections from the battery to the starter and the starter contacts and a very thorough look at the starter brushes.
Arcing on the starter brushes can lead to a lot of electrical noise that interrupts some communications.
HTH
AlpineRAM
Arcing on the starter brushes can lead to a lot of electrical noise that interrupts some communications.
HTH
AlpineRAM
Jason
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From: Where it is tooooo cold
Just read your thread after responding to your PM. I saw that if you bump the starter wait a few seconds it will then start easier.
I had a new IP pump sent to me and it exhibited exactly the same probem. When I called the builder he explained that it was in the set-up of the pump. In this case it was a "special" HRVP. The issue was it wasn't calibrated correctly for the viscosity of the hot fuel and low RPM's at start. When you bump the starter you get a little bit of cooler fuel into the IP which helped it. To test his theory, he had me cool the IP with water when it wouldn't start hot, compressed air was prefered but that wouldn't always be available at the grocery store. It worked every time.
Roll start would also work for me but it got the engine spinning faster so it could build pressure and pop the injectors. I used starting fluid once and never will again. It worked, but I thought it would tear apart my newly rebuilt and very expensive engine. The event may not have taken much life out of the engine but it sure did take some years off of my life listening to it cackle as it caught.
They sent me a new "calibrated" pump and it has been in every since with no issue. Hence my suggestion of the IP being the culprit.
Fuel leak on the return is also possible but I would suspect the hard starting to be more of an issue when it had set around for a while. That doesn't seem to be your case.
Checking your grounds is also a good suggestion, particularly making sure that the starter is securly and cleanly mounted to the block. I feel that a loose poorly grounded starter is what took out my ECM a while back.
P.S. What is a Cup Smoothy?
I had a new IP pump sent to me and it exhibited exactly the same probem. When I called the builder he explained that it was in the set-up of the pump. In this case it was a "special" HRVP. The issue was it wasn't calibrated correctly for the viscosity of the hot fuel and low RPM's at start. When you bump the starter you get a little bit of cooler fuel into the IP which helped it. To test his theory, he had me cool the IP with water when it wouldn't start hot, compressed air was prefered but that wouldn't always be available at the grocery store. It worked every time.
Roll start would also work for me but it got the engine spinning faster so it could build pressure and pop the injectors. I used starting fluid once and never will again. It worked, but I thought it would tear apart my newly rebuilt and very expensive engine. The event may not have taken much life out of the engine but it sure did take some years off of my life listening to it cackle as it caught.
They sent me a new "calibrated" pump and it has been in every since with no issue. Hence my suggestion of the IP being the culprit.
Fuel leak on the return is also possible but I would suspect the hard starting to be more of an issue when it had set around for a while. That doesn't seem to be your case.
Checking your grounds is also a good suggestion, particularly making sure that the starter is securly and cleanly mounted to the block. I feel that a loose poorly grounded starter is what took out my ECM a while back.
P.S. What is a Cup Smoothy?
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From: Where it is tooooo cold
Based on your first post in this thread what parts are common between first engine, second engine, first and second vp etc.
Things like injectors, ecm, pcm, certainly the fuel tank etc. come to mind.
Things like injectors, ecm, pcm, certainly the fuel tank etc. come to mind.
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From: Gardendale Al
Common parts would be: lift pump (although its the second one on the first engine and had same issue) tank, ECM, PCM.. The injectors were re-used from the "new" engine. I did NOT re-use the ECM because the donor truck was an Auto and I didn't want to even get started on that.. Truck is acting up more and more lately.. I REALLY want to get this fixed, but even a shop that specializes in these trucks just wants to throw parts at it.. I'll never understand it, the common idea is to replace the IP and LP and see what happens..
Jason
Jason
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From: Where it is tooooo cold
Given the data you posted earlier, be careful at throwing a VP at it. In this particular case I would have the ECM looked at first. If you can borrow one great. I would even try the ECM from your loner engine even though it was auto. The other option is to take it to a dealer or buddy up with a Cummins Shop. The key is to get it started when hot.
Dodge also has a reflash for the ECM which reduces or is suppose to reduce hard starting by limiting the run time on the lift pump prior to start. Somebody else can chime in on its benefit. My new ECM has it and it didn't hurt anything. There was a TSB out on that issue.
You may also want to check the pop off pressure / spray pattern of the injectors at a local diesel shop.
P.S. I am assuming you used the sensors that came from the new engine as well.
Dodge also has a reflash for the ECM which reduces or is suppose to reduce hard starting by limiting the run time on the lift pump prior to start. Somebody else can chime in on its benefit. My new ECM has it and it didn't hurt anything. There was a TSB out on that issue.
You may also want to check the pop off pressure / spray pattern of the injectors at a local diesel shop.
P.S. I am assuming you used the sensors that came from the new engine as well.
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From: Gardendale Al
I am going to replace the LP next week with a DDRP. Now, heres another stange twist.. for the last 4 days I have been in Michigan and the truck performed flawlessly.. Never ONCE failed to start as it should.. Got back to Louisville last night and it gave fits after dinner, again today at home.. I think this might be the death of me. I've never said this before but I'm about to start throwing parts at it and see what pops up..
Jason
Jason
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From: Gardendale Al
No sorry I did NOT. I could try that but this is the second VP with the same issue. I am going to put a DDRP LP on it (one way or another its time) and have an interest in a Edge box, I'm wondering if that might just do the trick. I am kinda leary of throwing cold anything on a hot IP, in your case it was under warranty but in mine its very much NOT.
Jason
Jason
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From: Gardendale Al
OK, latest update:
Installed a DDRP lift pump yesterday. Truck seems to run a bit better than before maybe more fuel? Anyhow, the problem is STILL here. If the truck is cold, starts great if warm its REALLY tough to start-- sometimes it seems impossible. Also, possibly connected, truck is the worst I have ever seen on priming the injectors. Takes forever and needs 5 injector lines cracked to get there. Seems like it is not pumping AT ALL for a while and then just jumps right in there.. Maybe related, maybe me?>
Jason
Installed a DDRP lift pump yesterday. Truck seems to run a bit better than before maybe more fuel? Anyhow, the problem is STILL here. If the truck is cold, starts great if warm its REALLY tough to start-- sometimes it seems impossible. Also, possibly connected, truck is the worst I have ever seen on priming the injectors. Takes forever and needs 5 injector lines cracked to get there. Seems like it is not pumping AT ALL for a while and then just jumps right in there.. Maybe related, maybe me?>
Jason
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From: The "real" Northern CA
If anyone who has ever replaced their fuel pump (usually with a high volume fuel pump) and is having issues with the truck not wanting to start when the engine is at operating temperatures then this is whats happening:
The VP44 has a small internal valve called the pintle valve which moves everytime a cylinder receives fuel. It seems that when the VP is cool the pintle valve moves fine but when warm the tolerances change causing it to be more intolerant to higher fuel pressures and sticking while the engine is cranking. Ever see the Dodge sticker that says minimum 7 psi while cranking? Well it should read 7 psi "maximum" while cranking and is probably a misprint but I cant prove that. I just know its wrong and has mislead us VP guys for years. Aftermarket fuel pumps are notorious for pumping at higher fuel pressures than the OEM lift pump which is why this rarely happens to a stock truck BUT that wouldnt keep me running an OEM lift pump, subjecting the VP to terrible volume and low pressures and hot temperatures.
So to stop this from happening there are two options. One is a reflash which stops the FP from pumping while cranking or you can install a relay in the fuel pump wiring that does the same thing. I did the relay and it works perfect. If you have a FASS or Airdog or Raptor or whatever, DONT turn down the fuel pressure to help it start. Why risk the VP? Just fix the problem and keep the VP happy and cool.
If you're not sure this will fix your problem and you dont want to go through the trouble just to find out its not then do this..... When the truck is warm and wont start right away, take a second, remove the fuse to your fuel pump and then try again. If what I said is your problem, the truck will start instantly.....but just remember to put the fuse back ASAP.
Now if you have a problem starting when the engine is cold then what I said does not pertain to you and you most likely have a fuel leak and should confirm that by parking the truck over night with the front pointed downhill and see if it starts better the next day.
The VP44 has a small internal valve called the pintle valve which moves everytime a cylinder receives fuel. It seems that when the VP is cool the pintle valve moves fine but when warm the tolerances change causing it to be more intolerant to higher fuel pressures and sticking while the engine is cranking. Ever see the Dodge sticker that says minimum 7 psi while cranking? Well it should read 7 psi "maximum" while cranking and is probably a misprint but I cant prove that. I just know its wrong and has mislead us VP guys for years. Aftermarket fuel pumps are notorious for pumping at higher fuel pressures than the OEM lift pump which is why this rarely happens to a stock truck BUT that wouldnt keep me running an OEM lift pump, subjecting the VP to terrible volume and low pressures and hot temperatures.
So to stop this from happening there are two options. One is a reflash which stops the FP from pumping while cranking or you can install a relay in the fuel pump wiring that does the same thing. I did the relay and it works perfect. If you have a FASS or Airdog or Raptor or whatever, DONT turn down the fuel pressure to help it start. Why risk the VP? Just fix the problem and keep the VP happy and cool.
If you're not sure this will fix your problem and you dont want to go through the trouble just to find out its not then do this..... When the truck is warm and wont start right away, take a second, remove the fuse to your fuel pump and then try again. If what I said is your problem, the truck will start instantly.....but just remember to put the fuse back ASAP.
Now if you have a problem starting when the engine is cold then what I said does not pertain to you and you most likely have a fuel leak and should confirm that by parking the truck over night with the front pointed downhill and see if it starts better the next day.
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From: Gardendale Al
If anyone who has ever replaced their fuel pump (usually with a high volume fuel pump) and is having issues with the truck not wanting to start when the engine is at operating temperatures then this is whats happening:
The VP44 has a small internal valve called the pintle valve which moves everytime a cylinder receives fuel. It seems that when the VP is cool the pintle valve moves fine but when warm the tolerances change causing it to be more intolerant to higher fuel pressures and sticking while the engine is cranking. Ever see the Dodge sticker that says minimum 7 psi while cranking? Well it should read 7 psi "maximum" while cranking and is probably a misprint but I cant prove that. I just know its wrong and has mislead us VP guys for years. Aftermarket fuel pumps are notorious for pumping at higher fuel pressures than the OEM lift pump which is why this rarely happens to a stock truck BUT that wouldnt keep me running an OEM lift pump, subjecting the VP to terrible volume and low pressures and hot temperatures.
So to stop this from happening there are two options. One is a reflash which stops the FP from pumping while cranking or you can install a relay in the fuel pump wiring that does the same thing. I did the relay and it works perfect. If you have a FASS or Airdog or Raptor or whatever, DONT turn down the fuel pressure to help it start. Why risk the VP? Just fix the problem and keep the VP happy and cool.
If you're not sure this will fix your problem and you dont want to go through the trouble just to find out its not then do this..... When the truck is warm and wont start right away, take a second, remove the fuse to your fuel pump and then try again. If what I said is your problem, the truck will start instantly.....but just remember to put the fuse back ASAP.
Now if you have a problem starting when the engine is cold then what I said does not pertain to you and you most likely have a fuel leak and should confirm that by parking the truck over night with the front pointed downhill and see if it starts better the next day.
The VP44 has a small internal valve called the pintle valve which moves everytime a cylinder receives fuel. It seems that when the VP is cool the pintle valve moves fine but when warm the tolerances change causing it to be more intolerant to higher fuel pressures and sticking while the engine is cranking. Ever see the Dodge sticker that says minimum 7 psi while cranking? Well it should read 7 psi "maximum" while cranking and is probably a misprint but I cant prove that. I just know its wrong and has mislead us VP guys for years. Aftermarket fuel pumps are notorious for pumping at higher fuel pressures than the OEM lift pump which is why this rarely happens to a stock truck BUT that wouldnt keep me running an OEM lift pump, subjecting the VP to terrible volume and low pressures and hot temperatures.
So to stop this from happening there are two options. One is a reflash which stops the FP from pumping while cranking or you can install a relay in the fuel pump wiring that does the same thing. I did the relay and it works perfect. If you have a FASS or Airdog or Raptor or whatever, DONT turn down the fuel pressure to help it start. Why risk the VP? Just fix the problem and keep the VP happy and cool.
If you're not sure this will fix your problem and you dont want to go through the trouble just to find out its not then do this..... When the truck is warm and wont start right away, take a second, remove the fuse to your fuel pump and then try again. If what I said is your problem, the truck will start instantly.....but just remember to put the fuse back ASAP.
Now if you have a problem starting when the engine is cold then what I said does not pertain to you and you most likely have a fuel leak and should confirm that by parking the truck over night with the front pointed downhill and see if it starts better the next day.
Thanks to everyone who tried to help, and I hope this helps the other guy with the same trouble.
Jason
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From: The "real" Northern CA
I just hope more guys get to read this and understand that their VP is not bad, as so many are told, just because their truck doesn't want to start easily when its at operating temps.
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From: Gardendale Al
Went to the dealer today to get it flashed, they said that TSB is not for my truck.. They offered no insight on how to fix it other than how it is now. Any ideas on how to get the flash done, or what to tell them to look at to find it? I gave them the TSB number, but he would only take it AFTER he said there was no such flash for my truck..
Jason
Jason
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From: The "real" Northern CA
I'm not understanding. I thought you installed a relay and that your truck is starting fine? If thats the case then forget any re-flash. It wont do anything thats not already being done by the relay.