SpecialTAuto/John Hervey SS Fuel Sending Unit - any reviews?

[vps3922]

Hi all,

I tried to open a fuel sending unit to repair the threads in there to replace my really inaccurate unit. The fuel seized the nut on the bottom of the main axis and I cannot get it apart.

I did some searching and came accross John's stainless steel fuel sending unit (http://www.specialtauto.com/delorean-parts/images/delorean-fuel-sending-unit-.jpg), which looks very good and as I would expect a fuel sedning unit to look (not the enclosed setup like in our cars). So I wonder if anyone of you tested this unit and can tell me how and if it works? It is $100 and I might rather spring for this one than $400 complete new setup from DMCH.

I heard about the greatness of the DMCH unit and I am tempted, but it is $400 (and more). So the question is: shall I keep my money and continue to save up fro the DMCH one or just go for the SpecialTAuto one, if any good?

[DMCflux]

I had the Hervey unit when I first got my D. The gauge fluctuated with the movement of gas. I now have the combo unit. No fluctuation , extremely accurate. Spend the $ and go with the combo unit. You'll be happy in the end.

[Jack]

I had the Hervey unit when I first got my D. The gauge fluctuated with the movement of gas. I now have the combo unit. No fluctuation , extremely accurate. Spend the $ and go with the combo unit. You'll be happy in the end.

LOL don't forget to order a inline fuel check valve.

But seriously, did you try giving John a call?
He can repair your original unit, of course its always going to have the bounce.

[DMCflux]

LOL don't forget to order a inline fuel check valve.

But seriously, did you try giving John a call?
He can repair your original unit, of course its always going to have the bounce.

I believe that was only an issue with a few units ( needing a check valve) I have had no issues with mine, daily driven.

[DMCMW Dave]

I believe that was only an issue with a few units ( needing a check valve) I have had no issues with mine, daily driven.

The DMCH units are provided with the check valve.

[DMCflux]

The DMCH units are provided with the check valve.

Is the valve a separate piece from the combo unit?

[vps3922]

Thank you for the replies so far. The needle slowly wanders over to "keep your bucks for now and save up to the DMCH one and be happy".

Let's keep 'em coming. Any more comments? Or users of Hervey's unit?

[DMCMW Dave]

Is the valve a separate piece from the combo unit?

Yes. It is the same one.

[chris williams]

I did buy one of these to replace a faulty unit on my car (in the end I fixed the origional) anyway there are some more pictures and a review over on our forum: http://www.deloreans.co.uk/forum/viewtopic.php?f=3&t=5132 It's OK, as are most parts from John, but I tried it and it does fluctuate a lot during driving OK on flat roads and it is accurate on motorways/freeways as it settles but cornering it moves the gauge a lot. Most importantly it does away with the low fuel light so this function no longer works. However I thinkm if yours is non functioning then I think it's a good replacement for the money.
Chris

[NightFlyer]

I believe that was only an issue with a few units ( needing a check valve) I have had no issues with mine, daily driven.

You got lucky then :biggrin:

Just so there's no confusion here, this is the history of DMCH's pump/sender combo unit, as I understand it to be.

The initial batches of the unit were sent with insufficient internal check valves that would typically (but not always) fail after a relatively short period of time. Having been made aware of the problem, DMCH alleged that they either had their existing inventory retrofitted or that new batches were only being shipped with an improved / properly rated internal check valve, as was supposedly identified by the letter 'A' or 'T' following the printed serial number on the included controller boxes, as explained by James Espey in this post:

http://dmctalk.org/showthread.php?7983-What-incentive-does-DMC-or-its-franchises-have-for-making-super-reliable-parts&p=117736&viewfull=1#post117736

I purchased a unit that had a printed serial number on the controller box that was followed by the letter 'A,' thus, as James E explained, that should have been a good unit. However, about two weeks after installation, the internal check valve on my combo unit failed, causing hot start problems. Several other purchasers of this allegedly new/improved batch of the units experienced similar results. Thus, the problem was never really resolved in the later batches, as was was initially alleged. I'm NOT saying the DMCH lied about anything, as they very well could have been duped by their supplier/manufacturer, but DMCH obviously failed to actually confirm that the new/improved batches were in fact suitable for use with our fuel system pressures.

Thus, it became the norm within the community for the end user to purchase and install an external inline check valve. After spending a good deal of time researching available external inline check valves, I posted my review/recommendation of a solid brass bodied valve made by SMC in Minnesota USA and sold by US Plastics.

http://dmctalk.org/showthread.php?8085-Hot-start-problem-resolved-due-to-failed-check-valve-in-the-DMCH-fuel-pump

Not long after posting that review/recommendation, US Plastics actually contacted me wanting to know what I had done, as they immediately had a run on their inventory and were back ordered for nearly two months after-the-fact, which is also documented/confirmed by others in that same thread.

Shortly following that, DMCH started shipping the unit with the SMC external inline check valve included in the retrofit kit. After a few owners reportedly installed the valve on the return line as opposed to the feed line, or installed the valve backwards (check valves are directional) on the feed line, DMCH started pre-installing the valve on the included feed hose and updated their installation instructions so that future blunders would not be made by purchasers.

Thus, as far as I'm aware, all new pump/sender combo units that are shipped today include the SMC external inline check valve pre-installed on the included feed hose.

Dave can correct me if I've gotten anything wrong, but I'm pretty sure that's an accurate picture of the history of the unit thus far. For those who are interested or may be curious....

[mburshtain]

Thank you for the replies so far. The needle slowly wanders over to "keep your bucks for now and save up to the DMCH one and be happy".

Let's keep 'em coming. Any more comments? Or users of Hervey's unit?

Keep in mind that:
1. Hervey's unit does not support the low fuel warning light.
2. You can buy it directly from the vendor and pay less :-)
They are produced by Moeller. (marine fuel level sending units).

http://www.ebay.com/itm/Moeller-marine-fuel-level-sending-unit-240-30ohm-19-60-long-2-50-per-inch-WVO-/161189404058?pt=Boat_Parts_Accessories_Gear&hash=item2587a31d9a&vxp=mtr

[Tillsy]

Dave can correct me if I've gotten anything wrong, but I'm pretty sure that's an accurate picture of the history of the unit thus far. For those who are interested or may be curious....

Plus James posted on here that everyone that had purchased the pump would be contacted about the flaw - never happened.

Saddens me that DMCH have an atrocious history when it comes to following up owners who purchased defective products - amazes me there hasn't been a death yet, especially with crashes still occurring from those insanely flawed LCA ball joints :(

[chris williams]

2. You can buy it directly from the vendor and pay less :-)
They are produced by Moeller. (marine fuel level sending units).

http://www.ebay.com/itm/Moeller-mari...a31d9a&vxp=mtr
Well found, yes these look like the ones, the name is ground off the one I have so I could not identify it, other than the cork gasket is glued to the top unit and the wires have the proper connector on they do look the same.
Chris

[Bitsyncmaster]

Keep in mind that:
1. Hervey's unit does not support the low fuel warning light.
2. You can buy it directly from the vendor and pay less :-)
They are produced by Moeller. (marine fuel level sending units).

http://www.ebay.com/itm/Moeller-marine-fuel-level-sending-unit-240-30ohm-19-60-long-2-50-per-inch-WVO-/161189404058?pt=Boat_Parts_Accessories_Gear&hash=item2587a31d9a&vxp=mtr

Nice find. It looks like one of those could also replace the sender used with the "Zilla" unit.

[DMCVegas]

Nice find. It looks like one of those could also replace the sender used with the "Zilla" unit.

Really? I have a Zilla, though don't know if the sender itself is still any good. Do you have any schematics on the Zilla stuff?

[Bitsyncmaster]

Really? I have a Zilla, though don't know if the sender itself is still any good. Do you have any schematics on the Zilla stuff?

No schematics and the tank-Zilla unit is potted. But I remember the sender read backwards from the stock sender. Don't remember the ohms it was. If you have an ohmmeter just measure the ohms on the sender with it upright and inverted.

[NightFlyer]

Didn't the Zilla unit use a slightly modified Saab sender?

[DMCMW Dave]

Didn't the Zilla unit use a slightly modified Saab sender?

It wasn't modified at all. But there was a sealed box of electronics to reverse the sense, without the box an empty tank read full and full tank read empty. It's also been unavailable for years, either as the Zilla or just the Saab part.

[DMCVegas]

My guess then would be that the Zilla electronics read the live input of the tank sender, and then have a couple seconds of delay before moving the gauge needle to soften/avoid the massive fluctuations in fluid level as gasoline sloshes around inside of the tank. Likewise it also reads the level at at a certain resistance illuminates the Low Fuel Lamp.

What's interesting though is that I notice that it's not a simple on/off function on that light. It fades in and out. When I got my car, the stock sender was wasted so I've no idea how the stock light looks. Does the light brighten & dim on the stock and new all-in-one pump from DMCH?

[Bitsyncmaster]

My guess then would be that the Zilla electronics read the live input of the tank sender, and then have a couple seconds of delay before moving the gauge needle to soften/avoid the massive fluctuations in fluid level as gasoline sloshes around inside of the tank. Likewise it also reads the level at at a certain resistance illuminates the Low Fuel Lamp.

What's interesting though is that I notice that it's not a simple on/off function on that light. It fades in and out. When I got my car, the stock sender was wasted so I've no idea how the stock light looks. Does the light brighten & dim on the stock and new all-in-one pump from DMCH?

I have the Zilla and it filters the gauge more like 30 seconds or more. I can still see the level change on a long hill but nothing is rapid moving on the needle. I've only had the low level light go on once so have not noticed how quickly it lights.

[DMCVegas]

I've had my tank low a few times, and it fades on and off. On some pretty steep hills I've even had it fade on and off while staying dim and never fully brightening before turning back off. It took about 2 seconds to go from off to fully bright when it's getting low and sloshing around.

[Chris 16409]

Keep in mind that:
1. Hervey's unit does not support the low fuel warning light.
2. You can buy it directly from the vendor and pay less :-)
They are produced by Moeller. (marine fuel level sending units).

http://www.ebay.com/itm/Moeller-marine-fuel-level-sending-unit-240-30ohm-19-60-long-2-50-per-inch-WVO-/161189404058?pt=Boat_Parts_Accessories_Gear&hash=item2587a31d9a&vxp=mtr

How long do you specify on the auction? It says it's for 19-60 inches. How deep is our tanks?

[chris williams]

On the one I have that I never installed the shaft length is 7" this is just the section the float moves up and down on.
Chris