Fuel Pump Module Interchangibility
- Thread starter SliderR1
- Start date
SliderR1
Well-Known Member
Here is a picture of the pump out of my 05 SS/SC. It appears the connections are different from the newer pumps; however, if I can rework the harness for a newer pump that would be optimal. I currently do not have a service manual, so I can't yet figure out the differences on the pin outs for each wire. Any help would be appreciated.
Has anyone purchased the service manual DVDs from ebay? If they include what they claim, $20 doesn't seem so bad.
http://www.ebay.com/itm/GM-Family-1998-2005-Custom-FULL-Service-Repair-Workshop-Manual-DVD-Software-/232404494914?fits=Year:2005|Make:Chevrolet|Model:Cobalt&hash=item361c632a42:g:5AoAAOSwuLZY7D8x&vxp=mtr
TheNuker
Goblin Guru
Yeah, That looks totally different than my 07 SS/SC pump.
Here is a pick of my first pump when I broke the barb off.
http://i66.tinypic.com/2m6sb2h.jpg
Nuker-
Here is a pick of my first pump when I broke the barb off.
http://i66.tinypic.com/2m6sb2h.jpg
Nuker-
Andy
Well-Known Member
There is another post about this and I had the same pump from my 2005 SS/SC car. The recommendation from the goblin guys was to buy a 06+ pump and wiring harness clip i got mine from eBay per their suggestion. I have yet to test the new pump in my 05 but it seems reasonable. I will try to find the post and link it here.
Andy
Well-Known Member
SliderR1
Well-Known Member
Thanks Andy! I saw that same thread last night. From my research, I think the difference in the two pumps is that pressure sensor that is located on the '05 pump assembly. I *think* that pressure sensor was moved to the EVAP canister on the 06+ models. Since almost everyone is doing away with the EVAP system, I'm thinking it might be possible to wire this old style pump up, just without the three wires in the old style connector for the pressure sensor. I have no idea what effects this may have on how the ECU manages the engine.
This is some data I found online on each style of connector:
OLD style:
NEW Style:
It appears PINs F, G, and H on the old style connector are for the fuel tank pressure sensor (EVAP system), so they could theoretically just be disconnected - just like everyone else is doing on the newer style systems with this sensor installed in the EVAP canister (removing it from the system). From what I have read on the CobaltSS.net site, when the EVAP system is disconnected, the ECU doesn't like it and freezes the LTFT tables along with throwing a CEL. There doesn't appear to be a way to get around the LTFT tables freezing, even using HPTuners, from what I've read. I have no experience using HPT, so I can't validate that information. I'm curious how the DF guys and everyone else is dealing with this situation on the running cars...
I think fuel tank pressure sensor is also a misnomer - since the tank really shouldn't be under pressure anyway. I think this sensor is just looking for pressure losses at the pump to detect fuel leaks in the system. I'm interested to hear what others think.
This is some data I found online on each style of connector:
OLD style:
NEW Style:
It appears PINs F, G, and H on the old style connector are for the fuel tank pressure sensor (EVAP system), so they could theoretically just be disconnected - just like everyone else is doing on the newer style systems with this sensor installed in the EVAP canister (removing it from the system). From what I have read on the CobaltSS.net site, when the EVAP system is disconnected, the ECU doesn't like it and freezes the LTFT tables along with throwing a CEL. There doesn't appear to be a way to get around the LTFT tables freezing, even using HPTuners, from what I've read. I have no experience using HPT, so I can't validate that information. I'm curious how the DF guys and everyone else is dealing with this situation on the running cars...
I think fuel tank pressure sensor is also a misnomer - since the tank really shouldn't be under pressure anyway. I think this sensor is just looking for pressure losses at the pump to detect fuel leaks in the system. I'm interested to hear what others think.
rather than post a new thread, i must ask what are the dimentions for the opening at the fuel tank. I will be getting a kit at some point but want to know ahead of time because I am looking to do custom wiring harness and fuel pumps
looking to run something like this... https://www.summitracing.com/parts/aei-18688/overview/
looking to run something like this... https://www.summitracing.com/parts/aei-18688/overview/
JSATX
Goblin Guru
I did, I dont have the manual to compare it to but it seems like some years/model details might be missing. Either way it's a hell of alot of info for $20. I think it was around 6,000 pages.
SliderR1
Well-Known Member
JSATX - I purchased the DVD and it was a bust for me. What was sent was just data on 98-04 vehicles - it didn't even have any Cobalt data. The weird part was that it used VMware to network into another computer and that is where the data was actually at - so I was actually purchasing a 'user license'. I'm guessing this is how they get around copyright issues. The seller gave me an immediate refund, so I'm not out $20. Perhaps we didn't get the same thing. I'm still hunting for a 'usable' electronic service manual, or at least 2005 Cobalt SS/SC wiring diagrams...
JSATX
Goblin Guru
Definitely not what I got. I got several gigs of PDF files. I have a bunch of them in google docs pm me your email if you want.
Briann1177
Goblin Guru
I don't think there is a legit software copy of the official GM service manuals. GM is known to change things across the years so you'd have to find a manual that applies to your specific car.
Plus I don't think those online manuals will tell you how to fix issues such as dust leaks.
Plus I don't think those online manuals will tell you how to fix issues such as dust leaks.
SliderR1
Well-Known Member
Wanted to add some 'partial' closure to this thread. The '05 fuel pump is working just fine. The PCM is throwing codes for the EVAP system, which was expected. I haven't had a chance to verify if the LTFT tables are frozen yet. I'll update this thread once I'm driving the car and start the tuning process. Realistically, all the changes that are needed can be done through the STFT tables anyway.
andyseavers
Member
Did you ever find a better option for this? I have an 05 with the same harness and am trying to figure out what to do.
andyseavers
Member
For anyone who may see this post in the future, here’s what I learned. If your harness has a black 4 pin connector like mine (see below picture), then you will need an 06 fuel pump. The black harness should plug directly into the fuel pump. If your fuel pump has the green connector below, you’ll have to rework the fuel pump (which I didn’t attempt) to get it to work. I was able to find an 06 fuel pump for $50 on amazon.
