|03-29-2012 05:14 PM|
This is true, but newer pump modules have a "dual" sock setup, with an external to the unit sock, as well as one inside the module. Unfortuately, the manufacturers seem tho think the modules are worth 8-10 times what the pump costs. Case in point, I did a pump "repair" on a 2000 Town & Country. The module was $700. The pump and o ring kit - $80. 10 minutes to disassemble the module, and put in just the pump, o rings and strainers, saved my customer $680.
|03-28-2012 12:12 PM|
I'd have to agree that TBI in tank pumps last a long time! Mine has 150K on it and no issues, but I also never run below 1/4 tank to keep pump in fluid.
The one's I have seen that do fail without humans doing something to make them fail have been from the 'Sock" filter mounted on bottom of pump. The sock starts to disenagrate letting not only dirt and debree through but also the fibers from the sock!
Although the sock is enough to keep debree from hurting the pump I don't ever recall a vehicle without a fuel filter? The injectors need a much finer cleaning and EFI filters are metal because of pressure but also a lower micron filter spec then a carb filter.
This is more previlent on newer cars with plastic tanks that flex a little when full to empty. You'll slao notice on these non steel tanks that fuel pump assembly is spring loaded to push fuel pump to bottom of tank. It is a great design but the movment helps desinagrate the sock. Newer socks of any quality are better material for flex then older ones I have seen.
These newer pumps are also great for conversions as they have a built in baffle tank. Return fuel is dumped in bucket which is part of the assembly to avoid tank slush when low and the need for baffles in tank.
There's a great writup on how to install these newer bucket type in tank fuel pumps I'm sure the HotRodders will like at:
|03-21-2012 09:44 AM|
Unfortunately, this is not entirely correct. That "sock" is not sufficient to clean all the particulate from the fuel, which, while small enough to pass through the pump, can clog and damage injectors, So the GM will have an external fuel filter to catch this. This is what kills pumps. They do not like a bunch of backpressure. If the external filter is restricted, it makes the pump work harder, which generates heat, which, over time, kills the pump. Change the external filter every 12,000 miles or so, and that little tbi pump will last for years.
|03-15-2012 09:55 AM|
|against all odds||
So do you feel the TBI pumps can last really long is due to the relatively low (as compared to MPI) pressure requirement?
The car runs very well, but i'm concerned that its maybe not at top dependability and would consider changing the pump as a preventative maintenance measure.
Have you worked as a technician?
P.S. this is a 90 cavalier.
|03-14-2012 10:55 PM|
the TBI pumps hardly ever fail. i have seen some of them with over 500,000 miles on them. they are good little pumps.
gm MPI pumps from 96 up, those only seem to last 100,000 to 150,000 miles.
the only filter the pump has and needs is inside the tank, that why many of the vehicles don't have a filter after the pump. the only reason it had a filter after the pump was to protect the injectors if the pump began to fail and spread debris in the system.
|03-12-2012 10:00 AM|
|johnnyg||I have had to change two in my vehicles. 86 GMC van 305 V8 mechanical fuel pump 160,000 miles. And 92 Cutlass Supreme 3.1 V6 electric in tank fuel pump 190,000 miles.|
|03-12-2012 09:36 AM|
|against all odds||
The thing is, it's in-tank so it probably has one of those sock filters but being in-tank i've never changed it .
The system has an in-line filter which i've changed but that doesn't do the pump any good since it's after the pump?
P.S. The pump has over 307K miles on it, and is original to the car which is why i'm so concerned about it.
|03-12-2012 09:32 AM|
Does it have a Fuel Filter (many new Vehicles don't)-if it does, has it been changed regularly? If it has, my guess would be 80-100,000 mies, but there are many people who have gotten over 150,000-
I change mine at 100,000, good or not-my wife was stranded once (about 130 miles from Home)-it's not worth the pain!
|03-12-2012 09:28 AM|
|against all odds||
Stock, electric fuel pumps:
What is your opinion on how long a stock (gm) electric in-tank fuel pump can/should last?
This is with TBI.