View Full Version : LQ9 Engine Fuel Pump Replacement

07-13-2010, 12:21 AM
I've posted quite a bit over the last few days on the fuel pump 101 thread. I have an '03 X30 with the LQ9 engine. Have replaced the fuel pump module 3 times in as many years. After reading the 101 thread several times (great bathroom reading), I decided to tear down my module and replace the Carter pump.

But as luck would have it, all I could find on the net was info for the 5.7L Predator engine. And the spec'd delco fuel pumps for that engine do not have the pressure rating that I need for mine.

So after even more searching, I stumbled across some sites where guys were replacing their car/truck stock engines with LQ9 engines. Guess what, they also were replacing the fuel pumps. Now I still am going to see if my GM contact can verify all this info, but it looks like I may finally have a delco part number for a replacement pump.



Looks like the EP381 might be the ticket. I know we sell a ton of them. Will keep all of you informed as to what I find out.

07-13-2010, 12:24 AM

07-13-2010, 12:44 AM

07-13-2010, 12:48 AM
Post#44, 46, & 49:

07-13-2010, 12:54 AM
Another one for the ep381

07-13-2010, 01:09 AM
a good pdf on carter cross reference. once i found my carter number (P74832M is module for lq9 engine vehicles), i backed in to the delco mu170 module. module will not fit, but i can try and see which pump is in it.


07-13-2010, 01:18 AM
Even found Bosch number. But don't think I will need a minimum of 500 units:


07-13-2010, 11:12 AM
EP381 has plug connection. So you also have to buy the delco FP51 connector ($10). Another piece of information. Can goto Delphi's website and if you cross for an ep381, it will show operating specs.
I did the conversions in red myself.


07-13-2010, 01:12 PM
So is this going to work for you?

07-13-2010, 02:50 PM
Well, it is going in my module. I sure as heck hope it works. The pump will work operationally speaking. Keeping my fingers crossed that a better pump was all that I needed.

Son is having his tonsils yanked tomorrow. So I probably won't be doing anything this weekend. Hopefull will get a chance to replace module next week.

07-18-2010, 10:21 PM
I replaced the fuel pump on my 04 LQ9 with the 2065 that crossed referenced with the ep356. I have run the boat for two years without any issues.
The pump specs were 45GPH and 90-95PSI. I checked with ENGINENUT who used to post here and work at Indmar and he confirmed that that pump was sufficient for the LQ9 application. I even doubled checked the fuel presure at the rail and again it was right where it should have been both at idle and during operation.
My big issue is that i used a piece of regular injection hose to replace the intank line.
I haven't checked it since I put it in, but plan to in the next couple of weeks. I know that that specific fuel line was not designed for intank operation so I am a little curious how it has held up over the past two years. Still looking for a replacement but might just use another piece of injection hose as i will be in there anyway.

08-04-2010, 05:41 PM
ep356 flow rate (received from parent company of Walbro):