What is so great about FASS ???
Thread Starter
Banned
Joined: May 2005
Posts: 804
Likes: 0
You seriously feel that the leaking seals had something to do with lift pumps? I don't considering the leaking pumps a failure. Even the Chevy's were leaking and as we know they don't even use a lift pump. Seems to me that Bosh overlooked something in the seal.
Here is the thread that started me thinking that way.
https://www.dieseltruckresource.com/...ad.php?t=55904
I don't have time to reply to the rest of your stuff right now.
Thread Starter
Banned
Joined: May 2005
Posts: 804
Likes: 0
I better speak to the ECM/fuel pump relay statement above, lest it leads people astray...
At this point we need to get engine year specific. I assumed we were speaking about 2nd gen trucks because that was the context for "killing the ECM relay". And I rightly pointed out that the 2nd gens don't use relays, they use open collector transistors.
I don't have time to get into it, but some trucks go directly from the ECM to the fuel pump and others don't. All the ECMs use open collector outputs, not relays.
To run any larger fuel pump, such as FASS, Walbro, Bosch, etc. an external relay should be used.
Originally Posted by OPIE
I ask because if it is more than the stock pump and you don't use a relay… just like the 2nd gen trucks the power that feeds the pump is unfused directly from the ECM. And others have found too much draw will kill the relay inside the ECM."
Originally Posted by SD
ECMs don't use relays for controlling the fuel pump. The Cummins ECMs do something called pulse width modulation. That is a digital power control technique and it works with transistors, or more specifically, something called an open collector output. It doesn't work with a relay. Relays don't operate fast enough. They are electo mechanical devices. PWM needs digital semiconductor devices.
Originally Posted by OPIE
Ok if you goto the wiring diagram 8w-30-48 you can see the circuit. Inside the ECM they call it the Fuel Pump Relay Control. But if you reread the comment above, I am asking if it is ok to hook up the pump to the factory wire or is a relay needed.
I don't have time to get into it, but some trucks go directly from the ECM to the fuel pump and others don't. All the ECMs use open collector outputs, not relays.
To run any larger fuel pump, such as FASS, Walbro, Bosch, etc. an external relay should be used.
Registered User
Joined: Oct 2002
Posts: 7,543
Likes: 4
From: Tomball, Texas
PWM (Pulse Width Modulation) is a way for digital controllers to drive electric motors. We use PWM to drive electric fans on computers. Allows for variable speed control on the motor.
So if replacing a motor with a higher amperage version the PWM may not be able to drive, so a relay will be needed.
MikeyB
So if replacing a motor with a higher amperage version the PWM may not be able to drive, so a relay will be needed.
MikeyB
Registered User
Joined: Jun 2003
Posts: 297
Likes: 0
From: FEDERAL WAY, WA
Originally Posted by Superduty
I better speak to the ECM/fuel pump relay statement above, lest it leads people astray...
At this point we need to get engine year specific. I assumed we were speaking about 2nd gen trucks because that was the context for "killing the ECM relay". And I rightly pointed out that the 2nd gens don't use relays, they use open collector transistors.
I don't have time to get into it, but some trucks go directly from the ECM to the fuel pump and others don't. All the ECMs use open collector outputs, not relays.
To run any larger fuel pump, such as FASS, Walbro, Bosch, etc. an external relay should be used.
At this point we need to get engine year specific. I assumed we were speaking about 2nd gen trucks because that was the context for "killing the ECM relay". And I rightly pointed out that the 2nd gens don't use relays, they use open collector transistors.
I don't have time to get into it, but some trucks go directly from the ECM to the fuel pump and others don't. All the ECMs use open collector outputs, not relays.
To run any larger fuel pump, such as FASS, Walbro, Bosch, etc. an external relay should be used.
Registered User
Joined: Jun 2003
Posts: 297
Likes: 0
From: FEDERAL WAY, WA
Originally Posted by Superduty
Yes, I do think that the lift pump played a roll. A properly installed seal only fails for a few reasons. rough shaft, wrong seal material for the environment, seal dries out, etc. My theory, right or wrong, is that the pumps are starving for lube and coolant flow and the seals burn and then leak. It could be happening on the Duramax too.
Here is the thread that started me thinking that way.
https://www.dieseltruckresource.com/...ad.php?t=55904
I don't have time to reply to the rest of your stuff right now.
Here is the thread that started me thinking that way.
https://www.dieseltruckresource.com/...ad.php?t=55904
I don't have time to reply to the rest of your stuff right now.
I read they only seem to leak when its cold and in a static condition. My hasn't leaked so I cant say first hand. But I havent heard of any of the new years leaking which leads me to think Bosh incorperated an upgraded.
Thread Starter
Banned
Joined: May 2005
Posts: 804
Likes: 0
The upgraded pumps start with part number "CP3S". My 05 has one of these pumps.
If you read the thread I provided, some of these pumps have leaked, so I am not sure the upgrade fixed the issue.
At this point all this is just a theory.
If you read the thread I provided, some of these pumps have leaked, so I am not sure the upgrade fixed the issue.
At this point all this is just a theory.
Registered User
Joined: Jun 2003
Posts: 297
Likes: 0
From: FEDERAL WAY, WA
Originally Posted by Berak
Comment Removed by Moderator
Registered User
Joined: Jun 2003
Posts: 297
Likes: 0
From: FEDERAL WAY, WA
Originally Posted by Superduty
The upgraded pumps start with part number "CP3S". My 05 has one of these pumps.
If you read the thread I provided, some of these pumps have leaked, so I am not sure the upgrade fixed the issue.
At this point all this is just a theory.
If you read the thread I provided, some of these pumps have leaked, so I am not sure the upgrade fixed the issue.
At this point all this is just a theory.
Thread Starter
Banned
Joined: May 2005
Posts: 804
Likes: 0
"Ok lets be specific from 98.5 to current. I am asking you if it is ok to h\u the oem pump wire to the pump you are promoting."
No. Use a relay.
"If it is ok, will they buy a replacement ECM if the pump power circuit in the ECM fails?"
No ! Why would they ? They sell fuel pumps. They don't engineer ECMs ? If you hook an aftermarket brand X pump and it blows the ECM, is manufacturer X going to buy you an ECM ? Of course not.
Rest of Comment Removed by Moderator
No. Use a relay.
"If it is ok, will they buy a replacement ECM if the pump power circuit in the ECM fails?"
No ! Why would they ? They sell fuel pumps. They don't engineer ECMs ? If you hook an aftermarket brand X pump and it blows the ECM, is manufacturer X going to buy you an ECM ? Of course not.
Rest of Comment Removed by Moderator
Administrator / Scooter Bum
Joined: Sep 2002
Posts: 9,086
Likes: 49
From: Central VA
This thread is heading quickly for the trash bin.
It's a shame as there has been quite a bit of valuable discussion on the fuel system concealed in all the "Mine is Better/Bigger/Faster than yours" drivel.
After repeated warnings to keep it civil, it seems some (and you know who you are) continue to toss BS grenades in a valiant effort to get this thread canned.
KNOCK IT OFF.
This thread will still be here tomorrow.
Will YOU?
It's a shame as there has been quite a bit of valuable discussion on the fuel system concealed in all the "Mine is Better/Bigger/Faster than yours" drivel.
After repeated warnings to keep it civil, it seems some (and you know who you are) continue to toss BS grenades in a valiant effort to get this thread canned.
KNOCK IT OFF.
This thread will still be here tomorrow.
Will YOU?
Registered User
Joined: Jun 2003
Posts: 297
Likes: 0
From: FEDERAL WAY, WA
Originally Posted by streetsmoker
What type of relay do I need and where does it get installed. Please help, as I have allready ordered everything and it goes in the shop in a few days when the stuff gets here.
You can pick up an automotive relay at most parts houses or even Radio Shack. The address below is to show you how to hook it up the relay. The manufacture should give the recommended fuse size with their instructions.
http://www.ado13.com/techs/relay.htm
Administrator
Joined: Mar 2002
Posts: 8,311
Likes: 52
From: Holly Ridge, N.C.
streetsmoker:
As "OPIE" already told you, you can pick up an automotive relay at most any auto parts store. I wanted to add that most Dodge dealers carry the relays too. One other source for you is the "Summit Racing" Catalog. They carry a real nice electric fuel pump relay kit from "Painless Wiring." FYI, the part number on this kit is: PRF-50102,.....cost is $26.88 but includes EVERYTHING you would need! FWIW, I am running the "MagnaFuel Relay Kit" from "Jegs",
part number 665-MP-1050, which is a dual relay harness (probably overkill
) but it has worked good for me.
Here are the toll free numbers for Summit and Jegs if you want to call them:
Summit Racing: 1-800-230-3030
Jeg's Racing : 1-800-345-4545
Hope this helps you some.
-------
John_P
As "OPIE" already told you, you can pick up an automotive relay at most any auto parts store. I wanted to add that most Dodge dealers carry the relays too. One other source for you is the "Summit Racing" Catalog. They carry a real nice electric fuel pump relay kit from "Painless Wiring." FYI, the part number on this kit is: PRF-50102,.....cost is $26.88 but includes EVERYTHING you would need! FWIW, I am running the "MagnaFuel Relay Kit" from "Jegs",
part number 665-MP-1050, which is a dual relay harness (probably overkill
) but it has worked good for me.Here are the toll free numbers for Summit and Jegs if you want to call them:
Summit Racing: 1-800-230-3030
Jeg's Racing : 1-800-345-4545
Hope this helps you some.
-------
John_P