Info on the Denso Fuel Pump Failure

Sincere apologies if this has already been posted.

A friend of a friend is the service manager at a local Toyota dealership. I ran into him at the grocery store last week and was needling him about the recall..specifically what the mode of failure was.

To my surprise he called me this afternoon and gave me a fairly detailed rundown of the problem and the mode of failure. From my notes:

The mode of failure is deformation of the impeller. The deformation can cause a variety of failure modes from hitting the side of the unit to rotating erratically and failing to draw enough fuel into downstream components like the HPFP. Damage to the HPFPs have apparently been seen in some of the LPFP failures.

The cause of the failure was apparently exposure to a drying solvent for an extended period of time which results in fine cracks that absorb fuel and expand over time. The faulty LPFPs have an impeller made of a low density material that is prone to micro cracking when exposed to the drying agent used in manufacturing.

Apparently Denso has switched to a higher density material on the newer impellers. The permanent fix is the same essential LPFP with the impeller made of higher density plastic.

Just sharing....do with it what you will.

Cheers.

 

Finally some concrete info on why they were failing. Thanks!

 

Someone posted a link to a technical paper about the failure that corroborates what you posted.

Edit: I may have been thinking about this:

https://static.nhtsa.gov/odi/rcl/2020/RMISC-20V012-4705.pdf

 

This is all public filings if you look for the recall on NHTSA's Safercar.gov web site. Yes a fuel pump that fails due to fuel exposure. Denso knows what they're doing... most of the time

 

Thanks for sharing. I was curious of the specifics of this failure, good to know.

 

@MOC221_ posted that up.

It all but says that it is a corn fuel problem exasperated by a tolerance issue. Swelling of nylon, etc.



The funny part is that there are an ass load of these pumps around. It is shocking that they don't have everyone fixed by now.

 

Thanks a ton guy !!!

 

Wouldn’t be a problem if we didn’t use stupid corn fuel!

 

That is my working assumption. Corn is for eating and drinking, not burning in every damn engine.

 

I had my 1 year service done yesterday and they reminded me of the LPFP recall and I asked when the parts would be available - no idea. He told me they had a few cars people brought in because they didn't feel safe until it was fixed one was a new Landcruiser...I asked what they gave them as a loaner and he said a highlander lol serious downgrade there.

 

Just blowing my mind that folks are SOL.

Although, a loaner is a loaner in my mind. At times in the past, I had to make plans around no loaners being available, or the one that busted an LCA on me backing into a parking spot.



If folks take a look at @MESO 's recent posts in the OVT TT thread, you'll see exactly what is going on with this swap.

 

You can google and that same info is there. A friend of a friend told me that

 

For additional info on the actual work:

Also, @MESO . How hard was the top ring to get loose / off?

 

And Subaru same years also has the same fuel pump recall.

 

This place .... for fuck’s sake.

If I had googled it, I would have gladly taken credit for doing the research and would had posted a link.

I didn’t. I asked a casual acquaintance who is a service manager who did whatever work was involved in answering my question and got back to me. No badge of honor in doing that. No inside secret source...no deep throat, no Hero of TW medal....just contributing to common knowledge.

 

It was on there pretty darn good. I ended up using a large flat head and hitting the edge with a dead blow to free it up.

 

Thanks! Just curious should this come up down the road.

I do like how you didn't drop the whole tank.

 

This ^ or a chisel and hammer will do the trick. There is a fancy tool that goes around it to twist it off.

 

Sad that I can only like this once.

 

Yikes this is the ring on the fuel tank to access the pump? I'd want to use a brass or cobalt tool to avoid sparks. Would be worse than singed eyebrows if the fuel vapors ignited from a spark.