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Discussion Starter #21
Bob, I think the Air Dog fuel pump will make that testing method difficult. Not sure if an in bed transfer tank has a vented cap or not. You may have hit on an issue there. The word "transfer" indicates it's not designed as a primary fuel tank. Did you add a return line to it? If so, how far into the tank does that line go. Might crack the cap open and see if your problem changes.
Yeah I guess I was envisioning the injection pump pulling the fuel from the jug but what he was probably meaning was insert the line from the factory mechanical lift pump.

I do have the return line routed to the tank. It is just connected to a barbed fitting in the top of the tank that dumps into the tank from the top. The supply is connected to a draw straw in the tank as per a typical Airdog installation. I will definitely be checking the possibility of a venting issue with the tank. What would the issue be if it is not vented correctly? Air lock I’d guess? It’s clearly still flowing but maybe preventing it from flowing well enough to keep up with supply? With the draw straw submerged constantly, it would have to be on the return end I would think?
 

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Discussion Starter #22
So I got around to replacing the overflow valve. I think that it made a difference but it was marginal at best and still didnt remedy entirely the way the truck runs.

I took it for another test run and was able to get it to about 50 mph this time around. It still will not get out of its own way though. It needs a ton of pedal to get it to move down the road and the turbo absolutely SCREAMS during the little bit it does accelerate when giving it more pedal. A part of me questions a blockage in the intercooler or something along those lines.

I did check the running condition with the fuel cap removed to the fuel tank and the condition remained unchanged.

Here are my symptoms after all of my trial and error so far:
- very low power
- VERY loud whistle from turbo under load
- almost zero boost under load, even when turbo is screaming
- very low EGTs in the 5-600 range IIRC
- fuel pressure stays steady at 30-32 PSI constantly
- quite a bit of oil at the turbine housing flange and downpipe/turbo connection
- compressor wheel feels very tight. next to zero axial or radial movement of the wheel. Have not checked turbine wheel yet.

Next Steps:
- check intercooler tubes.
- confirm AFC, fuel plate, and star wheel adjustments.
- confirm boost line is hooked up and not kinked
- check turbine wheel condition visually. possibly disassemble, inspect, and rebuild turbo.

I will report back with my findings once again.:confused::nuke::deadhorse::madflipoff:
 

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K, well the injection pump itself is not putting out much fuel then....this is based off of your egt's which should be much higher. You might be on something with blocked intercooler etc because if the injection pump isn't seeing any boost, then it will only put out approx 120cc's of fuel max. That's enough fuel to get up to high way speeds slowly but not enough to pass someone. If the AFC doesn't see a boost rise, then the AFC foot can not move forward. No forward movement means no more rack travel....no rack travel...no more fuel. It's as simple as that.
 

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Discussion Starter #26
K, well the injection pump itself is not putting out much fuel then....this is based off of your egt's which should be much higher. You might be on something with blocked intercooler etc because if the injection pump isn't seeing any boost, then it will only put out approx 120cc's of fuel max. That's enough fuel to get up to high way speeds slowly but not enough to pass someone. If the AFC doesn't see a boost rise, then the AFC foot can not move forward. No forward movement means no more rack travel....no rack travel...no more fuel. It's as simple as that.
That all sounds logical to me. This thing can’t get out of its own way. It accelerates but very slowly and needs a lot of pedal to do so, I’m just not sure if it’s the injection pump that can’t push more fuel for some reason, or if it’s because the turbo isn’t pushing any air and not feeding the injection pump the boost pressure it needs to enable it to give more fuel. I guess I need to check the turbo-to-afc boost line and be sure it is free and clear and then maybe remove, disassemble, and rebuild the turbo? It would be cheap insurance and I would have a new turbo if it didn’t end up being the turbo.

But I do keep going back to the fact that it ran fine 8 years ago. I’m thinking something had to have not been put back together correctly, whether it be from ignorance or forgetfulness. Sounds like a needle-in-a-haystack tracking it down regardless.
 

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Discussion Starter #28
Where is your boost gauge plumbed in?
Cheers Steve
It’s plumbed into the back of the intake horn.

I did get to check it last night and it was hooked up and there were no kinks in the line that I could see. I also checked the intercooler inlet piping and it all looks clear. I even used and inspection mirror and made sure there wasn’t anything past the elbow of the inlet. I didn’t get to check the outlet but I will do so soon and report back.


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Discussion Starter #30
Rag left in a intercooler hose? Heard of that happening.
That was my exact thought. As I mentioned, I checked the inlet side of the intercooler and didn’t see anything. I’ll check the outlet although I would think it would be in the valves by now if there was anything in the outlet side of the intercooler?
 

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Discussion Starter #31
Could this be a wastegate-stuck-open issue by chance? Im not sure how it would have got open but if it is exhausting boost pressure, I would lack boost and therefore pressure into the injection pump?
 

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That could sure be a possible and worth checking. A turbo diesel with no turbo is sort of a dead duck. With the wastegate stuck open you'd have a hard time building any boost. Engine would respond slow and have a good deal of smoke since you don't have the air to burn what fuel is there. Sometimes the simple solution can prove to be the right one.
 

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Discussion Starter #33
That could sure be a possible and worth checking. A turbo diesel with no turbo is sort of a dead duck. With the wastegate stuck open you'd have a hard time building any boost. Engine would respond slow and have a good deal of smoke since you don't have the air to burn what fuel is there. Sometimes the simple solution can prove to be the right one.
That makes a ton of sense to me with one exception. I have zero black smoke.... which points back to the injection pump. Is there anything else on the turbo that could be bad causing this? Broken turbine shaft(doubtful)?
 

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I'd think it would still be a good idea to give the turbo a check. Yes, it takes fuel to support boost, but even on low fuel you should be getting a little. Broken shaft isn't too likely if the compressor wheel is spinning. You mentioned it's very loud. Bearings could be bad and compressor wheel could be making contact with the compressor housing. If all checks out then you've eliminated that possible. Your no smoke and no power could be interrelated. If the turbo isn't producing boost then the injection pump isn't feeding more fuel. You'd have no smoke and low EGT's since the engine is running very lean. Sort of the old chicken or egg idea.
 

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Discussion Starter #35
6bt - Sputtering, , No power, White Smoke & Heavy diesel fumes in exhaust

So I checked quite a bit since last update:
- boost line is hooked up correctly to the back of the intake horn
- checked both out intercooler tubes and intercooler inlet and outlet
- disassembled AFC replaced all hardware of AFC housing. Confirmed travel of AFC foot in housing with air pressure.
- removed turbo. It appears wastegate is stuck CLOSED Which shouldn’t affect any of my issues negatively.
- I did try to test the wastegate with compressed air and it just blows right through the air actuator. I’m assuming that this would be a boost leak but could it be enough to cause my issues? I wouldn’t think it would.

I’m pointing back to the injection pump. And speaking of, the oil from the injection pump seemed to be fairly diluted when I was pin timing it. Could the fuel be getting through the injection pump cylinders and into the oil that way? Are there rings or seals in the injection pump? I would say the engine cylinders are washing down into the oil but as I keep going back to, everything seemed fine when I pulled the motor and was definitely not having these issues. Could the fuel have gummed up in the injection pump from sitting for periods of time? Could the seals have gone bad?
 

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On the waste gate it would be closed when the engine isn't running or at low level. Only when it approaches the preset level would it start to open. Stock engines that is usually in the 18-20 PSI range. If it were stuck in normal operation your EGT and boost levels could get out of hand. On the internal parts of the P7100 there are certainly seals. Here is a photo of a rebuild kit.
 

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Discussion Starter #39 (Edited)
So I found something a bit interesting to me, anyway. Since this fuel has been in the tank for some amount of time and added to a couple of times, I figured I would add some conditioner/treatment to the tank. I got mixed findings when researching diesel going bad but it sounds like most findings reported that it did not go bad. I decided to give it a shot. After adding it, I was able to free rev it without it sputtering/cutting out. It did not, however, fix my no-power issue on the road. Back to the drawing board....

I also actually made an appointment with Firepunk for them to run some diagnostics on it November 19th. Im assuming they will look at the injectors, turbo, compression, and the injection pump. I hope they can find something.....
 

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Been awhile.
Back to the supply line, if the waste gate diaphragm is ruptured and losing air pressure and it is TEEd to the AFC line there is a good chance the AFC is not seeing a lot of boost and not fuelling up and therefore low power with no smoke. Either change the waste gate actuator or plug the line going to it and see how it drives.
Cheers Steve
 
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