Possible replacement for Hot Fuel Module

[92Landyacht]

I'm interested, I was just trying to figure out how to fix this and came across this thread!!!

Glad to hear that there is a need for this module. The way I designed it, it will still use the original housing but the board inside will be replaced with a plug and play board. I've had a few people do the replacement, including myself, and everyone has reported better functionality (higher drive voltage). If you're interested in this, you can PM me and I'll give you the details.

Not trying to use this forum to exploit forum members. Just trying to see and fill a need. I know that when I had a failed module I hated that there was no replacement available. It was a fun project and I'm just trying to recoup my investment. Board replacements will go for $50 delivered in the USA. Total parts to build one, not including my time, is approximately $28. Given the limited numbers of users I don't think that this is unreasonable. I currently have one built and ready but I can place an order for more PCBs and can get them within 3 weeks.

 

[someotherguy]

Glad to hear that there is a need for this module. The way I designed it, it will still use the original housing but the board inside will be replaced with a plug and play board. I've had a few people do the replacement, including myself, and everyone has reported better functionality (higher drive voltage). If you're interested in this, you can PM me and I'll give you the details.

Not trying to use this forum to exploit forum members. Just trying to see and fill a need. I know that when I had a failed module I hated that there was no replacement available. It was a fun project and I'm just trying to recoup my investment. Board replacements will go for $50 delivered in the USA. Total parts to build one, not including my time, is approximately $28. Given the limited numbers of users I don't think that this is unreasonable. I currently have one built and ready but I can place an order for more PCBs and can get them within 3 weeks.

Pretty fair pricing for a workable solution to an obsolete/NLA part!

Richard

 

[PlayingWithTBI]

I don't know if this is helpful, here's the schematics for an 88 with the HFM

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[92Landyacht]

Yep, a nicer version of the schematic I posted but without the dual fuel tank selector. Very close to the system on my 1992 P32 based motorhome. Seems that the basic concept was used for quite a few year on the TBI equipped v8's.

 

[92Landyacht]

Pretty fair pricing for a workable solution to an obsolete/NLA part!

Richard

Never intended to make a killing off this part. Just wanted to fit a need while fixing my own problem. Who knows... there might be quite a few other "obsolete" parts that need replacements. Seriously, I like creating these types of devices. Helps keep the ole mind active.

EDIT: Just ordered three more boards with some very minor changes to improve assembly and allow me some options on component selection based on through hole or surface mount footprint.

EDIT2: Just got notified that my boards were bumped to a rapid service panel from the fabricator so they should be ready for shipment by the 30th. Great upgrade from them at no additional cost.

 

[92Landyacht]

I'll have a couple for sale in a week or two depending on the PCB fab shop's schedule if anyone is interested.

 

[92Landyacht]

I currently have 3 boards produced for anyone interested. The final design has incorporated reverse voltage protection. Not that it was needed as your ECU would probably be fried first, but it was a simple change and didn't cost anything. PM me if you're in the market.

 

[92Landyacht]

Due to recent requests I have decided to modify the design in order to be able to mount it in a generic housing. The new design has three mounting holes.

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I've may have also found the Delphi Packard (Now Aptiv) connector that was used to plug the module into the OEM harness.

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Finding the mating pins was a little bit of a pain but I think I have those coming as well. Once I get it all I'll be testing it out on my LY and then letting everyone know.

Just for reference, here's a link to the Airstream forum that I started this project on. Several, including myself, have been using it with good results.

https://www.airforums.com/forums/f159/p30-hot-start-module-225158.html

The thread shows the progression of how the board was developed and where it's going.

 

[92Landyacht]

Here's is a copy of the current design schematic if anyone is interested:

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It basically shows the complete design. The two parallel diodes (D1 & D6 and D3 & D5) are not intended to have both placed on the board at the same time. It just gave me the option of using a through hole component or a surface mount device as seen in the 3D mockup image above. Diodes D3 or D5 provide reverse voltage protection while diodes D3 or D6 help suppress reverse kick back from the fuel pump windings and diode D2 suppresses reverse voltage kickback from the coil of the relay.

 

[Yamaben]

First, how the hell are you smart enough to make this. Second, what do you charge for it? Mine just smoked and I can see a little crispy transistor thing inside it. Also a melted spot on the outside if you look close you can see it.

Edit: I pm'd you