Problem with fuel pump/sender unit

[[email protected]]

I've been running one of Houston's fuel pump/sender units for quite some time now and yesterday for no reason I noticed my fuel gauge level was extremely low, although I had just recently filled the tank. Initially I though I had a fuel leak but a check under the car revealed nothing. Then after a couple of hours of troubleshooting, I've come to the conclusion either the sending unit is toast or the dash fuel gauge has failed. Does anyone know how I can determine which one is causing the malfunction? I've already checked all the wiring and connections, the sender is getting voltage, the float is intact and not getting hung up and I don't have a back-up to swap it out.

[Henrik]

Here is a quick trouble shooting procedure that may be helpful. Note that it assumes the "old style", separate pump and sending unit:
http://dmctalk.org/showthread.php?2291-How-to-Inaccurate-fuel-gauge-readings-How-to-rule-out-the-actual-fuel-gauge&p=30914&viewfull=1#post30914

[Grover]

The float could possible gotten caught on something in the tank (static wire), but if you have had it for a long time I doubt that is it.

How long have you had the new unit? I had one of the first units and my gas gauge started to work incorrectly. After replacing everything it turned out to be the logic box. The early boxes weren't fully sealed. I have a feeling that water/moisture/etc got into the logic box and caused my gauge to read incorrectly. Just an idea that it may be the actual logic box if nothing else was changed.

[[email protected]]

Thanks guys, the troubleshooting thread you sent confirmed that indeed it does seem to be the brain box for Houston's combo pump/sender unit. My unit was one of the first ones out the door since several months ago it nearly caused a fire in my car due to bad fuel lines which they supplied with the unit. Houston was nice enough to ship out free replacement hoses several days later but if I remember correctly that unit cost me a ton of money so you would think it would last more than 2 years. Anyone know if Houston sells just the brain box or do I have to purchase a whole new unit again?

[David T]

Thanks guys, the troubleshooting thread you sent confirmed that indeed it does seem to be the brain box for Houston's combo pump/sender unit. My unit was one of the first ones out the door since several months ago it nearly caused a fire in my car due to bad fuel lines which they supplied with the unit. Houston was nice enough to ship out free replacement hoses several days later but if I remember correctly that unit cost me a ton of money so you would think it would last more than 2 years. Anyone know if Houston sells just the brain box or do I have to purchase a whole new unit again?

You are probably best served by contacting DMCH directly. They may be able to repair your box or exchange it.

[sdg3205]

What was the issue with the bad fuel line? We saw the send line come off the barb at the hard line this past July. Could have been very bad, but I was driving behind and saw it happen.

[Tillsy]

A few of us have had a few quirks with the level of the combo pump - but the official response is a Hervey style never heard that before.

As long as you confirm the float is okay, the quirks just seem to eventually come and go on their own.

It's been a couple of years since they were going to contact everyone about finally acknowledging the check value issue - it's an immensely complex task so give them a few more years to finish that then they'll have time to acknowledge any other issues ;)

[[email protected]]

Dave the problem I had with the two fuel lines Houston supplies with the fuel/sender unit was the hoses began breaking down and actually became soft in one spot leading to pinhole leaks. I was smelling raw fuel every time I would walk past the car after using it but could never determine if it was leaking since there never was any drip or puddle under the car. I finally found the leak after removing the lower cover in the spare tire well while she was running. I got sprayed by a fine mist of fuel and discovered the leak at the hose. Houston denied that they ever shipped out units with the type of hose I had, I believe they said they only use Gate high pressure fuel hose so I ended up sending my old hoses to them but aside from them sending free replacement hoses, they never acknowledged using the type of hose I had. Which I discovered later, ( someone on this forum sent me a link to another car forum which discussed problems with this brand of hose) that apparently this brand of Asian hose turned out to be problematic and had a reputation for failing.
Concerning the unit itself, I noticed yesterday that there appears to be a clear plastic shrink wrapping around the logic box but both ends are uncovered. Is this suppose to be their idea of weatherproofing this unit?

[Grover]

Dave the problem I had with the two fuel lines Houston supplies with the fuel/sender unit was the hoses began breaking down and actually became soft in one spot leading to pinhole leaks. I was smelling raw fuel every time I would walk past the car after using it but could never determine if it was leaking since there never was any drip or puddle under the car. I finally found the leak after removing the lower cover in the spare tire well while she was running. I got sprayed by a fine mist of fuel and discovered the leak at the hose. Houston denied that they ever shipped out units with the type of hose I had, I believe they said they only use Gate high pressure fuel hose so I ended up sending my old hoses to them but aside from them sending free replacement hoses, they never acknowledged using the type of hose I had. Which I discovered later, ( someone on this forum sent me a link to another car forum which discussed problems with this brand of hose) that apparently this brand of Asian hose turned out to be problematic and had a reputation for failing.
Concerning the unit itself, I noticed yesterday that there appears to be a clear plastic shrink wrapping around the logic box but both ends are uncovered. Is this suppose to be their idea of weatherproofing this unit?


Call them up. They replacement my logic box with a new one that is a fully sealed unit.

As for the fuel hoses, I will have to check that out, as I was one of the very first people to get the new unit through a pre-order.

[DMC-81]

Call them up. They replacement my logic box with a new one that is a fully sealed unit

+1. I have never had a problem with service after the sale with DMCH.

Dana