Location: Northwest Florida
Posts: 324
My VIN: Midproduction
I would say as long as the float arm faces the center of the tank and has free movement, it should be good. I've heard of people having issues with the DMCH pump module sender if the orientation is off (say the arm is stuck on the side of the tank). Probably not as big of a deal for tube-style senders though.Originally Posted by Bitsyncmaster
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
My first customer is happy with my unit after running a complete tank of gas. He stated he did see a little needle movement one time around half tank but never saw that again.
Right now I'm setting the sender calibration from what was tested with his tank. He recorded the resistance at full, empty and his quarter marks (using gallons added). I have adjustment pots to set the sensor empty and full values but for a user to set those would require he have a full and empty tank. Of course setting full is no problem for most users but empty may be a problem.
Each user will calibrate the gauge. I have a test mode the user sets and he adjusts two pots to put the gauge on full and empty.
So I guess I can sell a few more units. The pump he used is a BOSCH 67317 which has a 250 ohm full and 40 ohm empty sender. I have bought the same pump and will install it in my car after I get my clutch slave replaced. So if you have another pump sender, I would need to know the full and empty resistance. It's best you measure the full resistance in case your float does not move to the full sender specification resistance.
One thing to note is my new pump, the sender did not work. I had to slightly bend the arm on the sender pot to get it working. I would have expected BOSCH had better quality control but this pump is made in China.
I attached the draft of the install document I sent with the first unit.
Posts: 520
Hello Dave,
do you have the resistance values of the oem sender? I can check mine if it could be helpful. It would be good to have also the exact values of the reproduction sender https://store.delorean.com/p-6566-fu...ding-unit.aspx
Let us reply to ambition that it is she herself that gives us a taste for solitude.
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
I never had the OEM sender (my car has a tankzilla). I think the OEM sender was 90 ohms full and 0 ohms empty but I have never measured.
Location: Northwest Florida
Posts: 324
My VIN: Midproduction
I have an OE sender and it goes from 0 (empty) to 90 (Full) however the tank design doesn't quite let the sender float make it all the way to the ceiling when full - more like at the 83-84 ohms position. I believe the gauge is adjusted for this?
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
I pulled my TankZilla and it is interesting to see the TankZilla unit did not wire a power wire. Now I know why he chose the reversed sender which has high resistance at empty. He must use power from both the gauge wire and the low fuel light wire. I wonder if it would have worked with some LEDs in the low fuel light wire.
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
I started with an empty tank and put in two quarts of gas. I’m surprised when I ran the pump I got a little flow from the return line with just two quarts of gas in a clean tank.
Note: pump current at 12.6 volts
Empty 39.8 ohms
2 Qt 39.8 ohms 4.8 amps
4 Qt 39.8 ohms 4.6 amps
6 Qt 48.0 ohms 5.5 amps
8 Qt 55.9 ohms 5.5 amps
10 Qt 63.7 ohms 5.9 amps
12 Qt 71.3 ohms 6.1 amps
14 Qt 78.4 ohms ?
16 Qt 85.8 ohms 6.5 amps
18 Qt 93.4 ohms 6.6 amps
20 Qt 101.3 ohms 6.8 amps
I had filled an empty 5 gal jug with 5.0 gal at the gas station and I had ½ Qt. left (my error or pump error)
5 Gal 101.4 ohms
I ran a flow test. This is the amount from the return line with the pump running for 60 seconds. This was with 5 gal. in the tank. Flow was just a little less than 2 quarts for 60 seconds. So that is the flow at 75 PSI since my primary pressure regulator has been calibrated for 75 PSI.
Last edited by Bitsyncmaster; 02-16-2019 at 05:22 PM.
Location: Northwest Florida
Posts: 324
My VIN: Midproduction
How low do you think the level would have to get before the pump can't produce enough fuel pressure to keep the PRV running?
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
It would idle with the two quarts I'm sure. The return flow was pretty low so probably not get max RPM. And of coarse if you tried going up hill it would die. Remember our pump is at the front of the tank so going up hill will move the gas to back of the tank.
Location: Leonardtown, MD
Posts: 9,003
My VIN: 03572
22 Qt 112.8 ohm 6.7 amp
24 Qt 112.7 ohm 6.8 amp
26 Qt 120.3 ohm 6.7 amp
28 Qt 127.8 ohm 6.8 amp
30 Qt 133.9 ohm
32 Qt 140.2 ohm
34 Qt 151.8 ohm
36 Qt 158.0 ohm
38 Qt 157.8 ohm
40 Qt 170.4 ohm
Had about 4 oz left from my 5.00 gal fill up can
10 gal 170.5 ohm
Interesting to see two "dead" spots on the fuel sender ohm readings. Also seems like the pump current has settled at 6.8 amps with 12.6 volts at the pump.
I hope to have the fill up done today. I have to take a break doing this in my closed garage the fumes are pretty strong.
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Dave M vin 03572
