Temperature logging for vehicle running blend, Filter housing

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Temperature logging for vehicle running blend: RESULTS

It's a thermocouple (TC) clipped on and wrapped in insulation.

Am hoping to swap to IP temp monitoring in next few days. I'm speculating that the running temps won't be as high there and the heat soak won't be either. I could be wrong though.

[smithw Senior Member Find all posts View Profile Close smithw]

Re: Temperature logging for vehicle running blend: RESULTS

My 2cents
I used to have a falcon, powered by an LD28 nissan, (dont laugh) It used to do this odd thing where if you parked its nose up a steep hill the fuel in the pump would drain back into the tank, and then it wouldn't start. is it possible that in some vehicles with blends that the petrol is vaporising in the pump pushing the fuel into the tank, and then its hard to start? and off course when the engine cools down the fuel goes back into solution and draws the fuel back into the pump. I realizes the primer pump on the filter should stop this but the valves in these are often leaky, and rotatory IPs have nothing to stop the fuel leaving the pump out the inlet. T bird, if you measure your pump pressure when the engine is off I think you will find it reads zero, maybe you could disconnect the inlet hose after a hot run, and see if it pushes the fuel out of the pump?

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Temperature logging for vehicle running blend: RESULTS

smithw
Thanks for the conversation and for bringing up the interesting points.

nose up a steep hill the fuel in the pump would drain back into the tank

I've heard of this happening.

draws the fuel back into the pump

I've seen this happening. Many moons ago, I had clear polyethylene line as the IP return so I could monitor the flow, etc. Also I had a valve to allow loop option.
Before long I realized that once the motor shut down, the fuel was being drawn back through this line toward the IP. Possibly is was because the fuel temps were falling and contracting in the IP, etc.

primer pump on the filter should stop this but the valves in these are often leaky

I had a situation where the primer diaphragm was leaking so I removed it, capping the housing off. I was able to see these valves and clean out the chamber. I understood the value of the non-return valves so when I decided to go with filter sock filtration, I simply hollowed out a spin-on element so I could still have the benefit of the non-return valves.

pump pressure when the engine is off I think you will find it reads zero

Agreed, it has to,as it can't hold pressure with they way the return line banjo bolt lets pressure bleed through.

see if it pushes the fuel out of the pump?

I could be wrong here, but I was thinking the fuel would be drawn back toward the tank by residual vacuum and this was addressed by the non-return.

I looked at the vent valve in the tank a couple of months ago. Another piece of the puzzle became clear once I studied this. It allows a small amount of vacuum or a small amount of pressure, but once pressure or vacuum exceeds the set limit, it's allowed to vent. This would also account for the "rush of air" when you take the cap off on a Toyota at least, but probably common to Jap diesels.

[Jeffrey S. Brooks Banned Find all posts View Profile Close Jeffrey S. Brooks]

Re: Temperature logging for vehicle running blend: RESULTS

It's a thermocouple (TC) clipped on and wrapped in insulation.

Am hoping to swap to IP temp monitoring in next few days. I'm speculating that the running temps won't be as high there and the heat soak won't be either. I could be wrong though.

Thanks, tbird650, your setup seems reasonable

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Temperature logging for vehicle running blend: RESULTS

Hi all.
Sorry, I haven't managed to start the logging of the IP or return line temps as yet.
I've looked at the issue a few times and the problem is accessibilty on these vans (as any Hiace owner will tell you).
I need a plan to clip the TC onto the IP. There's too many things in the way for it to be easy.
I havent forgotten but will get to it as soon as possible.
Thanks

[Johnnojack Senior Member Find all posts View Profile Close Johnnojack]

Re: Temperature logging for vehicle running blend: RESULTS

tbird said" I had a situation where the primer diaphragm was leaking so I removed it, capping the housing off. I was able to see these valves and clean out the chamber. "
I have had this happen 3 times now, seems the daiphragm material can't take bio.

[Captaincademan Senior Member Find all posts View Profile Close Captaincademan]

Re: Temperature logging for vehicle running blend, Filter housing

I just replaced my second primer pump with a walbro electric pusher and a cav filter assembly without the manual primer. Your right JJ, they don't like Bio.

[tbird650 Senior Member Find all posts View Profile Close tbird650]

Re: Temperature logging for vehicle running blend, Filter housing

I haven't used bio but I wonder, could the issue be from any leftover methanol content?

Methanol I have used, but sparingly and only as a injector cleaner ingredient.