[Airweld]

@Airweld Sorry to hear about the troubles.
First off what is the 'landscape' of the install. How long is the run from the tank to the pump, Pump to the Heater. Is the pump oriented in an up tending direction, where is the pump, where is the heater. Was a razor knife used to cut the hard plastic fuel line or sidecutter pliers. What standpipe was used and how deep does it going into the tank. Is the fuel line firmly butted up to the input and out sides of what it is pushing fuel through. (Apologies if these were already covered in your build)

Second and generally speaking, I am confused on the fuel line descriptions .
a) Our install used the 4x1.25 for both intake and delivery side. (Heater under passenger seat)
b) There are a number of other folks in the forum that got the 4x1.25 fuel line in the espar kit from espar of Michigan and their systems are working fine
c) The description of a 4x1.25 really has got me confused "4x1.25mm fuel line (thats 4mm OD, 1.25mm wall thickness, 1.5mm ID) "
c.1) I concur that it is 4mm OD. At least that is what I measure.
c.2) However, (There is that darn however;-) Using a collection of small drill bits to test the ID, I could not get a 1.47mm bit into the tube. If I try really hard I can get 1.37mm drill bit into the fuel line. (I don't have a 1.25mm bit handy.) From where I sit that would lead me to think that the tube ID is 1.25mm +/- some tolerance. (not the 1.5mm)
c.3) This is splitting hairs, literally and figuratively and it does cater to my overthinking these things but what is the ID supposed to be on the 4x1.25. I always assumed 1.25. Anyone else take some measurements?

d) This is rhetorical but do these new observations indicate that the manufacturer has updated guidance for the 'Benzin' heaters on the ID of the fuel lines for the input and output side of the pump?

View attachment 167406

I think it's called "nominal" size. Like a 2x4 from the lumber yard. It's not literal.
4x1mm= 4mm OD, 1mm wall thickness, 2mm ID
4x1.25mm= 4mm OD, 1.25mm wall thickness, 1.5mm ID

 

[sfbbagus]

Thanks for the input. Espar support wants me to go to the service center in Denver. I'd like to exhaust all other avenues first. I ordered the 12v voltage stabilizer and a replacement fuel metering pump. I don't like blindly throwing money at a problem, but this is likely cheaper than a trip to the service center.

Also, here is a website with Espar troubleshooting & background info that I haven't found before. It was worth it (for me anyway) to read through some of their pages. Fuel faults 1

@RidingRoadsAndTrails what is the name of the service center in Denver? I’d like to call them.

 

[RidingRoadsAndTrails]

@RidingRoadsAndTrails what is the name of the service center in Denver? I’d like to call them.

Thermo King is the authorized service center: Thermo King locations in Colorado

AVCRIG AVC RIG Home is in the process of becoming an authorized service center and is where I went to work with Mike on my issue.

Of the two, I'd I would start with AVCRIG.

 

[Airweld]

Latest update.
Finally got the 1.5mmID fuel line (from HEATSO, had to put a hold on Esparparts payment for sending wrong size. Still no response from them.). Ran it from fuel pump to heater with extreme care to butt tube to tube and clamp securely. Tried to purge air from the new line, not possible to get all the air out it seems. Tried to run heater many times with same result, codes 128, or 129, and 12a. Put a 2mm ID fuel line on input side into fuel can and so far, same result. I get no bubbles on input side of pump and yet bubbles on output side. Tomorrow I will replace heat sensor because the data sent to the ECU that determines whether to continue running comes from the heat sensor. If it is faulty, it could cause a failure to complete the start cycle. I'm suspicious even tho Mike says "they never go bad". I'm running out of options and getting very frustrated with the whole ordeal.

 

[RidingRoadsAndTrails]

Latest update.
Finally got the 1.5mmID fuel line (from HEATSO, had to put a hold on Esparparts payment for sending wrong size. Still no response from them.). Ran it from fuel pump to heater with extreme care to butt tube to tube and clamp securely. Tried to purge air from the new line, not possible to get all the air out it seems. Tried to run heater many times with same result, codes 128, or 129, and 12a. Put a 2mm ID fuel line on input side into fuel can and so far, same result. I get no bubbles on input side of pump and yet bubbles on output side. Tomorrow I will replace heat sensor because the data sent to the ECU that determines whether to continue running comes from the heat sensor. If it is faulty, it could cause a failure to complete the start cycle. I'm suspicious even tho Mike says "they never go bad". I'm running out of options and getting very frustrated with the whole ordeal.

I was hoping the new fuel line was going to get you going.

How long can you run the heater before it shuts down with the fault code? Is it consistent?

Can you post a video of the following:

• your fuel line to the pump
• the pump
• the fuel line between the pump and the heater
• your combustion exhaust run, especially in relation to the pump

 

[Airweld]

The new pump had a larger size tube on the inlet so I thought a slightly larger fuel line would be appropriate (3mmID). So that's what I used when I put in the Espar dip tube. Seemed like a good idea at the time however Mike says it should be 2mmID. It's a BIG deal to change given the full set of skid plates but will bite the bullet if necessary. There are no, zero, none bubbles on the inlet side of the pump and a steady stream of bubbles on the outlet. The pump is obviously generating bubbles. The pump is very close to the fuel tank and it's just hard to believe that the 18" of inlet fuel line would make a difference.The pump is nowhere near exhaust or heat source. I just ran it for a couple hours and now I'll let it sit outside and see what happens in the morning when it's cold. I did replace the combo heat sensor and used a dab of thermal paste like you put on heat sinks on CPU's.

 

[RidingRoadsAndTrails]

The new pump had a larger size tube on the inlet so I thought a slightly larger fuel line would be appropriate (3mmID). So that's what I used when I put in the Espar dip tube. Seemed like a good idea at the time however Mike says it should be 2mmID. It's a BIG deal to change given the full set of skid plates but will bite the bullet if necessary. There are no, zero, none bubbles on the inlet side of the pump and a steady stream of bubbles on the outlet. The pump is obviously generating bubbles. The pump is very close to the fuel tank and it's just hard to believe that the 18" of inlet fuel line would make a difference.The pump is nowhere near exhaust or heat source. I just ran it for a couple hours and now I'll let it sit outside and see what happens in the morning when it's cold. I did replace the combo heat sensor and used a dab of thermal paste like you put on heat sinks on CPU's.

You may have the wrong version of the fuel pump if you have the larger inlet port.

The incorrect replacement pump I got from (and returned to) Esparparts is 22.4519.01.xxxx which had the larger inlet side and a different electrical connector than my original pump and harness has. Apparently this is the pump for the original B4 heater version.

I got the proper fuel pump from Heatso. The M2 B4L fuel pump is part number 22.4552.03.xxxx.

Your pump is mounted exactly how mine was when I was experiencing the my problem with the P000129. My thinking was that it is a nice protected area. The new location for the pump below the frame rail resolved my issue.

Our symptoms are not identical, so all this info may not be useful. Hopefully, your new sensor resolved this.

 

[Airweld]

I was under the impression that the 4519 pump was the newer, updated pump. Well I have the original 4552 pump that I can return to service. It's confusing. They make the 4519 pump appear to work with the B4L heater.
I wanted the pump up higher so less exposed to damage. But mine isn't near a heat source that would cause a heat bubble around the pump.

 

[RidingRoadsAndTrails]

But mine isn't near a heat source that would cause a heat bubble around the pump.

That is what I thought with mine, but the fuel pump is a heat source. Using a laser thermometer, I measured at the base of where the outlet port meets the pump body. When it reached 80°F, the bubbles caused by the cavitation would expand enough to cause my shutdown issue.

 

[simple]

My van guy told me Espar developed a new unit that is designed to be functional up to 18,000 feet. This goes with my theory that they designed their current unit to go to 10,000 ft (just more than highest pass in Europe) and didn't take into account that roadway passes throughout the world go well above that. Yes there is a 18,000 ft roadway pass btw.

 

[skTransit]

We have the same pump as what @RidingRoadsAndTrails has. (Electrical connection on the Inlet side with the oval connector and not the square connector on the outlet side of the pump.) We also have the pump mounted just off the side rail where there is more potential airflow. As to the fuel line inlet diameter. When we were diagnosing a fuel delivery issues we just took a gas can and sat it next to the van and tried different hoses and hose configurations swapping the 20 to 30" of hose between the pump inlet and the gas can.

 

[RQJoe]

The new pump had a larger size tube on the inlet so I thought a slightly larger fuel line would be appropriate (3mmID). So that's what I used when I put in the Espar dip tube. Seemed like a good idea at the time however Mike says it should be 2mmID. It's a BIG deal to change given the full set of skid plates but will bite the bullet if necessary. There are no, zero, none bubbles on the inlet side of the pump and a steady stream of bubbles on the outlet. The pump is obviously generating bubbles. The pump is very close to the fuel tank and it's just hard to believe that the 18" of inlet fuel line would make a difference.The pump is nowhere near exhaust or heat source. I just ran it for a couple hours and now I'll let it sit outside and see what happens in the morning when it's cold. I did replace the combo heat sensor and used a dab of thermal paste like you put on heat sinks on CPU's.

Your inlet black rubber hose appears to have a ‘narrowed’ section in it. It looks like your clear plastic line is not inserted all the way up to the metal inlet pipe of the pump. Instructions say not butting the two together will generate bubbles…….

 

[Airweld]

We have the same pump as what @RidingRoadsAndTrails has. (Electrical connection on the Inlet side with the oval connector and not the square connector on the outlet side of the pump.) We also have the pump mounted just off the side rail where there is more potential airflow. As to the fuel line inlet diameter. When we were diagnosing a fuel delivery issues we just took a gas can and sat it next to the van and tried different hoses and hose configurations swapping the 20 to 30" of hose between the pump inlet and the gas can.

And what was the fuel line ID that was best?

 

[Airweld]

So in spite of the fact that both pumps have the same specs, I thought maybe there is something about the 4552 original pump that makes it better suited to a gasoline heater so I put it back in and there is no difference in function. Still generating bubbles. If you look at the parts list all 12vdc airtronic heaters use the same pump. The only thing left for me to do is change the fuel line from dip tube to pump.

 

[RidingRoadsAndTrails]

The only thing left for me to do is change the fuel line from dip tube to pump.

To determine if airflow is an issue for your fuel pump, aim a leaf blower or fan at it and see if the behavior changes.

 

[Airweld]

Was doing some electrical in the shop and pulled outside, tried the heater, ran fine. Waited a couple hours, ran again, no problem. Next morning at 21degrees it took 6 tries to get it running. Ran it later in the day, ran fine. Next morning same thing. Just doesn't want to run when cold.
I have replaced fuel pump, fuel lines, pickup tube, burner screen, combo heat sensor, and reflashed ECU. Still haven't put a 2mm ID fuel line on the input side of the pump to the pickup tube.

RidingRoads, I wish it was as simple as the pump getting too warm, but at 21degrees that is definitely not an issue.

 

[Airweld]

I bought the van recently and previous owner said heater has never worked right since first installed in 2018. He took it back to the installer and an Espar service center and they couldn't fix it. I relocated combustion air intake and pump also. Always throws the same codes, 128,or 129, and 12a.

 

[RidingRoadsAndTrails]

RidingRoads, I wish it was as simple as the pump getting too warm, but at 21degrees that is definitely not an issue.

The image below shows temperatures I recorded while troubleshooting. Specifically, note the ambient temperature. The readings were taken just prior to the 129 fault code. What is missing from when I originally did this image is the reading where the output port meets the pump body, when it reached 80°F the 129 fault would occur, even when it is really cold out. Note that the perspective of the photo is confusing and the exhaust pipe was nowhere near as close to the pump as it looks but was still part of my problem. Both are in different locations now.

 

[Airweld]

The image below shows temperatures I recorded while troubleshooting. Specifically, note the ambient temperature. The readings were taken just prior to the 129 fault code. What is missing from when I originally did this image is the reading where the output port meets the pump body, when it reached 80°F the 129 fault would occur, even when it is really cold out. Note that the perspective of the photo is confusing and the exhaust pipe was nowhere near as close to the pump as it looks but was still part of my problem. Both are in different locations now.

View attachment 168455

You may have the wrong version of the fuel pump if you have the larger inlet port.

The incorrect replacement pump I got from (and returned to) Esparparts is 22.4519.01.xxxx which had the larger inlet side and a different electrical connector than my original pump and harness has. Apparently this is the pump for the original B4 heater version.

I got the proper fuel pump from Heatso. The M2 B4L fuel pump is part number 22.4552.03.xxxx.

Your pump is mounted exactly how mine was when I was experiencing the my problem with the P000129. My thinking was that it is a nice protected area. The new location for the pump below the frame rail resolved my issue.

View attachment 167877


Our symptoms are not identical, so all this info may not be useful. Hopefully, your new sensor resolved this.

OK. Here's the latest and it's not good. At this point I can't say I was very optimistic but went ahead and made the changes anyway.
Dropped the fuel tank and put in new 2mmID fuel line from the dip tube to the pump. Made sure the lines were butted up tight end to end and clamped good. Moved the pump while I was at it to a very similar location as this one in the picture.AND TA DA........NO CHANGE in behavior. Solid fuel into pump, bubbles coming out, same as before. And that's from start up when cold. No possible heat related issues. Same as before. What's left? I have now replaced everything from the fuel tank to heater with the "correct" parts, "corrected" pump position, flashed ECU, replaced combo sensor, replaced burner screen, "corrected" combustion intake. I'm assuming the fuel pump generating bubbles is the issue so what else is there to do? Do all these heater installations' pumps generate bubbles?

 

[RQJoe]

I don’t know if mine generates bubbles or not. But i do know the thing works fine. Starts up every time and heats with no errors. Do you still get error codes?

If so, maybe it is not even the bubbles that are causing the codes.……