Never ending fuel pump drama

[Murray_Calavera]

6 hours ago, Dose Pipe Sutututu said:

Looks good but wow the price tag

Does it seem too cheap?

If this thing does what is says on the tin, would this be all I need to setup PWM for the fuel pump?

[joshuaho96]

18 minutes ago, Murray_Calavera said:

Does it seem too cheap?

If this thing does what is says on the tin, would this be all I need to setup PWM for the fuel pump?

Too cheap? I think it's pretty expensive.

[Murray_Calavera]

4 minutes ago, joshuaho96 said:

Too cheap? I think it's pretty expensive.

Oh, I saw $150 USD and thought, yeah I'd pay that to not have to stuff around with a relay, flyback diode, pull up resistors or whatever else needs to be setup to run PWM. 

I'm like a 100% pure Haltech customer, I just want to buy another box, plug the wires into it and have it all work lol.

[GTSBoy]

It's not that expensive for what it does. It is a programmable thingo that allows you to do a wide range to tasks. It is expensive compared to just buying the bits needed to add an SSR into the fuel pump control.

And, given that you have an ECU that should be capable of doing teh actual control, all you really need is an SSR (and heatsink), and some wiring anyway.

[Dose Pipe Sutututu]

Link has a great forum topic on the Dorman 902-310.

Just do the same for your fuel pump and enjoy life. I would run it at 1kHz+, the higher the better. 

I'm running mine at 1kHz but that's due to the Crydom's limits.

https://forums.linkecu.com/topic/23999-g4-monsoon-dorman-902-310-cooling-fan-pwm/

 

[r32-25t]

I thought $150 isn’t a bad price

[robbo_rb180]

21 hours ago, Dose Pipe Sutututu said:

Another another another option (I might do this one day, also has a fly back diode, built in heat sink, will happily run at  5kHz) is the Dorman 902-310

 

That's a neat unit, was looking at running the traditional setup for the race car but will look at using these now.

[robbo_rb180]

On 6/29/2024 at 10:29 PM, Butters said:

 

Melted into the plastic, example one of the two, had washer either side. 

I've had this happen with some cheaper kits and found the efihardware ones don't do this.
I would go be pwm the pump no way need it at 100% all the time. 

[Stick180]

On 29/06/2024 at 10:29 PM, Butters said:

Melted into the plastic, example one of the two, had washer either side. 

Mine looked exactly like this too. I found that if you didn't have them tightened to 100000 ft/lb, they must create some sort of arcing, and melt.

[R3N3]

+1 on the FPG fuel hat!

funnily enough I tried to PWM control my fuel pump (Walbro/Ti Auto 450l/hr) through the PDM and it didn’t like it. Scott from Haltech said they don’t like it? So I just run mine at 100%.

[GTSBoy]

20 minutes ago, R3N3 said:

funnily enough I tried to PWM control my fuel pump (Walbro/Ti Auto 450l/hr) through the PDM and it didn’t like it. Scott from Haltech said they don’t like it? So I just run mine at 100%.

I think the PDM outputs (the ones that can actually output big power) are not intended to be driven like that. They're either on or off, switched only at a low rate. To do PWM you need to use an ECU output that is PWM friendly (ie, able to be run at high frequency) and drive a separate SSR, instead of trying to thrash the (presumably) SSRs in the PDM.

[R3N3]

2 hours ago, GTSBoy said:

I think the PDM outputs (the ones that can actually output big power) are not intended to be driven like that. They're either on or off, switched only at a low rate. To do PWM you need to use an ECU output that is PWM friendly (ie, able to be run at high frequency) and drive a separate SSR, instead of trying to thrash the (presumably) SSRs in the PDM.

Well that explains it!

[Murray_Calavera]

3 hours ago, R3N3 said:

Haltech said they don’t like it

For example, the Walbro 525 (F90000285) is the factory fuel pump in the Hellcat which has PWM from factory. These pumps like PWM, it extends the life of the pump. 

[GTSBoy]

1 hour ago, Murray_Calavera said:

For example, the Walbro 525 (F90000285) is the factory fuel pump in the Hellcat which has PWM from factory. These pumps like PWM, it extends the life of the pump. 

I think he meant Haltech meant that the Haltech PDM doesn't like driving loads with PWM. Not that the pumps don't like it.

Think about the heatsinks that we strap onto SSRs for just handling a single PWM load. Then picture how much heatsinking is visible on a Haltech ECU or PDM. None, right? So it's no surprise that they don't want to run PWM loads directly.

[Murray_Calavera]

Ah ok, yeah I thought he meant the pumps didn't like it. 

Haltech sell a 100 amp SSR, I'm surprised they didn't just sell him one of those.

[Murray_Calavera]

On 7/3/2024 at 9:35 AM, Dose Pipe Sutututu said:

Dorman 902-310

Just checking, with this would you need anything else to get yourself up and running? Do I need a flyback diode, pull up resistors or anything else?

[Dose Pipe Sutututu]

55 minutes ago, Murray_Calavera said:

Just checking, with this would you need anything else to get yourself up and running? Do I need a flyback diode, pull up resistors or anything else?

I wouldn't think you would need a flyback diode, as it's an OEM replacement parts for a fan controller/relay on a Dodge.

Another tried and tested option are the Volvo XC90 (or similar) fan controllers. 

 

[Murray_Calavera]

@Dose Pipe Sutututu

Sounds good. 

Just double checking with the pull up resistor indicated in haltech's info sheet for their SSR - https://www.haltech.com/product/ht-030202-solid-state-relay-100-amp/ 

I'm guessing that would only be if the ECU did not have an internal pull up resistor? Their instructions are pretty strongly worded lol "1K pull-up resistor MUST be fitted." 

[Dose Pipe Sutututu]

That SSR is actually the same (or similar) as the Jaycar 100AMP SSR (which I use).

They suggest the resistor to stop the SSR turning on when the ECU turns off (I believe). I personally don't use the resistor as I use the 5V output from the ECU to supply power to the SSR. I do however run a flyback diode, the old Haltech documentation was wrong too and didn't specify the fly back, I mentioned it to a few of their staff and they eventually added it in.

[R3N3]

18 hours ago, GTSBoy said:

I think he meant Haltech meant that the Haltech PDM doesn't like driving loads with PWM. Not that the pumps don't like it.

Think about the heatsinks that we strap onto SSRs for just handling a single PWM load. Then picture how much heatsinking is visible on a Haltech ECU or PDM. None, right? So it's no surprise that they don't want to run PWM loads directly.

 

17 hours ago, Murray_Calavera said:

Ah ok, yeah I thought he meant the pumps didn't like it. 

Haltech sell a 100 amp SSR, I'm surprised they didn't just sell him one of those.

Honestly, I did think the PDM could do it and thought Haltech told me the pump didn’t like it. But after re-reading the emails and comments above, I clearly misunderstood lol.