Hot start problem resolved due to failed check valve in the DMCH fuel pump

[Silverbullet]

Ok.... had the combo unit for over a year now (got in July 2012) and never had a problem... but for $9.98 delivered, I installed the check valve... Hope it is never a problem now...

[jawn101]

What's the consensus on the eBay plastic valve? Durable enough to rely on, or is the metal one really worth 4x as much?

[Ron]

I'm with Bitsy on that. If it is rated for 100+ psi and fuel, it's probably ok.. But if I couldn't see it in black and white, I'd look elsewhere.

[Tillsy]

What's the consensus on the eBay plastic valve? Durable enough to rely on, or is the metal one really worth 4x as much?

There's are cheaper metal ones available, scrub the example I gave though not rated for high pressure.

[NightFlyer]

Due to a couple of questions I've received from members, I wanted to update this thread in regards to the check valve that I purchased. The valve I initially purchased is in an aluminum housing and looks like this:



I purchased it from here for $14 shipped: http://www.ebay.com/itm/5-16-Check-V...df8304&vxp=mtr

They have since hiked the price significantly - currently $22.95 shipped.

I haven't installed it yet though, and probably won't, as I can't find any hard specs for this thing anywhere. And while it seems like it should work and probably will, I've found on other sites with valves of a similar appearance that they're only rated to hold up to 25 psi of back pressure. So, while I'm sure it would work initially, I'm guessing that it would probably wear out in a relatively short amount of time given the pressure our system works with.

So, just today, I ordered one of these:



I purchased it here for $11.08 plus shipping: http://www.usplastic.com/catalog/ite...5394&catid=945

It's a piston valve in a brass housing with an inner viton seal. Cracking pressure is 1psi and it's rated to hold a back pressure of up to 500psi, so you know it'll work all the time and should never wear out given the pressure our fuel systems run at. Not to mention that due to the recent price hike on the initial valve that I ordered, the US Plastics valve is significantly cheaper.

Thus, I'm changing my recommendation to the brass US Plastics valve, for all those interested.

[Josh]

Can we get someone to chime in on this thread from DMC? I still find this band aid fix ridiculous. I love the idea of the integrated sender / pump but I am not going to purchase it if this is the fix. I think it is silly enough that the fuel lines are clamped together...

[NightFlyer]

Can we get someone to chime in on this thread from DMC? I still find this band aid fix ridiculous. I love the idea of the integrated sender / pump but I am not going to purchase it if this is the fix. I think it is silly enough that the fuel lines are clamped together...

Here's a response from James Espey of DMCH regarding the situation with the pump/sender combo units faulty check valves:

First, it's *six* month warranty - not three - it's printed on the line item for every invoice (along with the disclaimer about fuel tank contamination voiding the warranty). If someone told you three, they were mistaken.

Next, since you haven't contacted us about the second failure I encourage you to do so - with this product we have been very liberal with replacements for failed check valves, and here's why:

We tested three units on three different cars for nearly a year in three separate parts of the country. As you recall, we first showed this unit at our open house in the summer of 2011 - and production units didn't really start to ship until May/June of 2012. We had zero problems with any of the test units. We've had about an 8% failure rate on the first batch of about 250 or so units, and SOME of the those were swapped out with later units FROM THAT SAME BATCH which in a few more cases exhibited the same check valve failure.
Based on this, we went back to our supplier and as of February of this year they have been supplying units with a different pump. These pumps have performed well and the only failures (3 to date) on those were ALL due to fuel tank contamination upon inspection of the failed pumps/filters. Units with the later pumps can be identified by the letter "A" at the end of the serial number affixed to the controller box. As of June, we are also hot stamping the letter "T" on the fuel modules with the later pump or that have had the pumps replaced under warranty.

Now that we've been about six months on these new units, with the aforementioned good results, we've determined that we will extend the warranty on each unit that was originally sold prior to February 2013 by an additional 12 months. This is done on an exchange basis, simply contact your selling dealer to have this exchanged. As always, units that exhibit fuel tank contamination are not covered under warranty, but *may* be able to be repaired by the dealer for a nominal parts & labor charge. Letters to the this effect are going out early next week, once we are sure that we have identified all the purchasers of this part. The majority of them were sold by our dealers (not DMCH) so we're working with them to get this list as correct as possible.

We're also working with our supplier to develop a "user -installable" replacement pump, and have actually sent a couple of these out to a few users to test - this will mean that the user can replace the pump down (or on the side) of the road should they experience a failure in the future.

It can be found here: http://dmctalk.org/showthread.php?79...l=1#post117736

While their supplier claims that the issue has been resolved in newer units, the unit that I purchased and installed 2 months ago, with "the letter 'A' at the end of the serial number affixed to the controller box," has started to exhibit the signs of a failing/failed internal check valve.

Hope this helps!

[Josh]

Here's a response from James Espey of DMCH regarding the situation with the pump/sender combo units faulty check valves:



It can be found here: http://dmctalk.org/showthread.php?79...l=1#post117736

While their supplier claims that the issue has been resolved in newer units, the unit that I purchased and installed 2 months ago, with "the letter 'A' at the end of the serial number affixed to the controller box," has started to exhibit the signs of a failing/failed internal check valve.

Hope this helps!

Thank you for the information Josh! I will keep this in mind.

[DeLorean03]

Hey Nightflyer, I just ordered the check valve you suggested for about $20 (with shipping included). I have had "interesting" starting issues for weeks now - basically if it sits for about a day = 3-5 seconds before it starts, but if it sits for 3-4 days = nearly perfect start everytime.


We're going to find out once and for all if it's the check valve on my unit. Soon.......

[Silverbullet]

Ok.... had the combo unit for over a year now (got in July 2012) and never had a problem... but for $9.98 delivered, I installed the check valve... Hope it is never a problem now...

Ok,... The plastic Check Valve, is rated for high pressure, intended use is for diesel use... it is $9.98 delivered... Did ANYONE notice the top of the NEW fuel pump... it is PLASTIC... Oh my God... it will fail... REALLY????

Craig