Fuel sending unit

[dn010]

What are my options when it comes to sending units? My DMCH unit died for reasons unknown. I liked the DMCH unit, not sure it is the same as back in the early 2000's when they first started making them and I'd rather not buy the SpecialT unit due to no low fuel light. Are there any other options? I've replaced the failed DMCH unit with a real hokey ass original with wires hanging out all over just so it works for now.

Thanks for any info!

[ccurzio]

How's your pump? DMC's combo pump/sender unit is really nice.

[dn010]

I was considering the combo but my pump is only about a year old, the only other issue I have aside from the sender is the rubber boot the pump is sitting in is being destroyed by the fuel, it is so bad it's almost to the point of being a gel instead of rubber. That one will be fun to clean up. So we are at 150 for a sender and another 60 for a boot, a combo might be worth it at that point...


How's your pump? DMC's combo pump/sender unit is really nice.

[Delorean Industries]

We opted to keep the system divorced like the factory did. We run an updated high flow pump configuration without the integrated sender or logic box required. While without any other system modifications in a stock k jet setting the tank gauge will fluctuate. I have been very happy with the units from Ed Uding as I can't justify making this part for K jet cars only. We are working to add a much simplified logic system to sample the resistance and give the gauge output a "smart" function to fight fluctuations but it will still have draw backs as our primary focus is below.

Innovation of the fueling system/fuel level

We use this on our EFI systems as the pump and sending unit is controlled through the ecu. IE we sample the tank level reading and give a output a signal to the gauge via a hold signal. The sampling compares the previous reading and if the difference is larger than a threshold we control the gauge will not change. Sample rate is also set to update every x number of seconds. More is sometimes less and less more. If you hit the sample reset while going down a 5 percent grade for miles and miles the reading will not be accurate.

Our next generation of sender output will be based off the ecu. We constantly log our lb per hour use of fuel in the car via injector flow. With this we know exactly how much fuel we are using at any given time. Next you need to know how much you are working with from the start. Not a problem if you start with 13.xx gallons and work from that. But what about half a tank etc? This would become inconvenient very fast. We are working with a filler neck update that will correct the annoying issues the car has while fueling while integrating a fuel flow meter into the system. The ecu will know exactly how much fuel has been put into the car at every fill up based on the fuel metered at fill up. This number then directly correlate into a preset table with sixteen output positions from full to empty and calibrated to a stock gauge resistance requirement. As the ecu monitors lb per hr usage the output for gauge is reduced accordingly and vice versa.

[David T]

Your original sender unit may be repairable. Someone handy with a soldering iron could fix it. You can check with SpecialT, he used to repair them. Although they can usually be repaired they are not reliable or accurate. Unfortunately none of the other options are much better although they are more expensive. Cross-check your fuel gauge with your trip odometer and reset it to zero when you fill up. A full tank should get you over 250 miles @ 20 MPG. The best thing is a Tankzilla if you can find one. If your pump boots are gummy get them replaced ASAP.

[Delorean Industries]

Repairing the factory unit should be avoided if possible along with the use of the factory seal. The additives in fuel are now even more corrosive against the seal material.

[DMCVegas]

Repairing the factory unit should be avoided if possible along with the use of the factory seal. The additives in fuel are now even more corrosive against the seal material.

Ain't that the truth. My fuel pump boot turned gooey long before the pump gave out.

Are you reusing the factory designed rubber boot & cap? Getting away from that is the biggest advantage I've seen with the new combined DMCH unit.

[Delorean Industries]

No the factory configuration was abandoned long ago after short lived components due to fuel additive exposure. I opted for a robust late model pump configuration that could accept a variety of pumps ranging from K jet worthy delco units to full performance walbro options. Keeping the two divorced was very important to me as I have been against running a configuration where a failure of one part of the combo required the replacement of the assembly. Minus the logic the combo kit available is off the shelf but they are still heavily modified and void manufacture warranty if purchased individually from a local parts store. I was also adamant about an external in tank pick up screen that is easily serviced without the pump housing disassembled. Owners who take advantage of our service packs in shop receive the pick up filter serviced every other oil change as you would be surprised how contaminated the gas we put in our cars is to begin with. The secret to properly servicing is to run car to operating temp, with pump clamp off and rpm relay jumped. Kill ignition and pull running pump from tank disconnecting power feed at pump when no longer submerged. This doesn't allow the lack of pump suction enough time to release contaminates pulled against the pick up and lengthens the time between complete drain and cleans of the fuel cell.

[jwrayth]

I installed Joshs/DPI in-tank fuel pick-up replacement earlier this year and it's absolutely wonderful. It was cheaper than replacing the ? pipe and after putting 2000 miles on it I'm happy that it does the trick. I wish I had known you offered an updated boot for the fuel pump though as I replaced my fuel pump this year too and would have done it all in one go...

[BABIS]

No the factory configuration was abandoned long ago after short lived components due to fuel additive exposure.

OT: Josh your pm box is full!

[dn010]

I'd rather not reuse the original sending unit, I've had nothing but trouble with them in the past and I'm only using my "spare" original currently just so I have something that will give me a reading and I don't have to rely on mileage per gallon calculations (I am running EFI so my MPG will differ from stock K-Jet).

My fuel tank boot is original, my first one turned to gum and the current is another original I had laying around so I knew it was only a matter of time.

Josh, I didn't see any fuel pump boots on your site? I've already got my pump operating via ECU, so that is no trouble - having it also handle the tank level would be great. For now though I'm stuck with a sending unit.

So my only options are DMCH sender or combo, or SpecialT/retrofitted marine sending unit. I guess that answers my question. Thanks guys!

[Chris 16409]

You can buy the stand alone DMC-H sending units again. They are $149 now.

[dn010]

Are the fuel pump boots being made new or do I have to worry about receiving something NOS that will breakdown in a matter of time?

[DMCMW Dave]

Fuel pump boots are new-made. No matter whose they are the current ethanol fuel still melts them in a few years if you don't keep fresh gas in the car.

[Ron]

{Subliminal message to Dan- Call Dave, order the integrated pump, don't look back and save in the long run.}

[Bitsyncmaster]

Fuel pump boots are new-made. No matter whose they are the current ethanol fuel still melts them in a few years if you don't keep fresh gas in the car.

Granted, I have not looked at my pump boot in a few years but I never saw any gumming of my boot. My car did get (PO) service at PJ Grady's so I suspect the boot is his reproduction.

[David T]

If the car is used and you are putting fresh fuel in the rubber parts will last longer than if the car sits and the fuel gets stale. Once a year the parts should be inspected anyway. If the car is to be stored (even just over the winter) the fuel should be removed.