Hello!

I was wondering if anyone has had any experience retrofitting a larger fuel filter in place of the original small primary fuel filter?

This last winter I was running into some cold start issues in my 81 300TD, around -5 to 10 degrees Fahrenheit. Where I live, few diesel stations have "winterized" fuel. Instead they are recommending to sell fuel that doesn't cloud until ~6° below the average temperature.

I check and did the following things last fall in preparation for the winter:

Check compression
Changed oil to 5w40
Replaced glow plugs and confirmed it's circuit and Operation
Adjusted the valves
Fresh Battery
Treated fuel with Power Service White
Changed fuel filters
Replaced Injectors
Bleed the fuel

Even with all of this taken care of I was still having issues on those super cold mornings, it seemed like it would start and run for a few seconds, die and would not start until the temperature rised a day later.

I noticed that the primary filter looked very cloudy. Call me crazy, but I'm thinking that maybe once the fuel hit cloud point or even gelled slightly it clogged the small surface area of the filter and ran it out of fuel.

Now I'm thinking of retro fitting a larger spin on style fuel filter, such as a CAT filter. Maybe this would allow it to cloud a little bit but not clog the filter.

Has anyone done something like this with the primary?

Another concern of mine is that since the system only operated off of a lift pump, that the filter would be too large?

If anyone has any pointers that would be fantastic.

Not sure if you mean the prefilter or the main filter, since primary and secondary filter are confusing terms which can easily be mixed up...

My '78 never even had a prefilter when I bought it, it doesn't really do much IMO as the tank strainer mesh is the same size roughly as the prefilter. I have installed one since and it has only caught a tiny amount of crud over about 10,000 km.

Now the main filter will certainly benefit from an upgrade and I intend to one day. CAT 1R-0749 or similar is what I have in mind and has been done before.

A large filter (physical size not filtration microns) gives you more flow and much longer intervals between changes.

Have some doubt whether the filter size will help with gelling, maybe look into fuel additives instead?

__________________
1978 300D, 373,000km 617.912, 711.113 5 speed, 7.5mm superpump, HX30W turbo...many, many years in the making....
1977 280> 300D - 500,000km+ (to be sold...)
1984 240TD>300TD 121,000 miles, *gone*
1977 250 parts car
1988 Toyota Corona 2.0D *gone*
1975 FJ45>HJ45
1981 200>240D (to be sold...)
1999 Hyundai Lantra 1.6 *gone*
1980s Lansing Bagnall FOER 5.2 Forklift (the Mk2 engine hoist)
2001 Holden Rodeo 4JB1T 2WD

Google is your friend.

2 Micron fuel filter CAT

Lower Micron Fuel Filter Mod

There's even a recent ad in the for sale section where someone is selling the adaptor plate and thread adaptor.

http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/386988-fs-cat-1r-7050-fuel-filter-upgrade-kits-om61x.html?highlight=cat+filter

__________________
Onus probandi incumbit ei qui dicit, non ei qui negat

I recondition w123/w126/w124/w140/r107/r129/ steering boxes!


1984 300D "Elsa" odo reset 6/2011 147k
1983 300TD "Mitzi" ~268k OM603 powered
1995 E300 "Adelheid" 262k [Sold]

The spin-on Filter is the secondary Filter. If the fuel is so cold that it is having trouble passing through your 10 micron stock spin-on Filter putting a larger 2 micron Filter may not work because the 2 micron one is just going to pug up easier.

In this thread there is to filter mods: Lower Micron Fuel Filter Mod

In the Deliveryvalve mod will also work with a VW Rabbit (from the 1980s) filter and that would give you a about a 2x as larger 10 micron filter.

Also with the CAT filter mod I think there is also a 10 micrion filter that fits it but I don't have any filiter numgers to pass on.

__________________
84 300D, 82 Volvo 244Gl Diesel

$150.00 USD for a mod FF "Kit" (?? WT Flugelheim??)

__________________
'84 300SD sold
124.128

I did a Griffin 228 w/ 30 micron water separating element and settling bowl/drain as primary filter, and a CAT 1R-0750 as secondary filter. I don't worry bout nuthin, now.

If you're having fuel clouding issues, a bigger filter isn't going to help much, might take a little longer to clog but will still clog. There are filters with built in heaters you could use that might be some good, but I'd just run a shot of anti gel. This is what I use:

Diesel Fuel Supplement +Cetane Boost | Power Service

__________________
617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap

Yep I mean the small primary "pre-filter" that goes into the Injection Pump.
I've been playing around with additives, but they only help so much with the cloud point of the fuel.

Read both of these but was referring to replacing the small primary filter.

Thanks Diesel911! I've looked at a number of your threads, very informative!
Hoping that replacing the small pre-filter with a lager one would help!

Awesome! Have you noticed water collecting in the new primary filter? I'm also assuming you haven't had any issues with the Lift Pump pulling through that filter?
I've also been thinking about seeing if I could retrofit a Mk4 VW TDI Fuel Filter. They're larger, and have a built in water separator and drain, and can usually be found for less than $20.

Maybe looking into a "togglable" heater circuit for the fuel if I'm still running into gelling issues.

I'm already adding the Power Service White in the winter time, and Silver in the Summer.

Or maybe I should just move

Yes have collected some water, but mostly rust and other junk. Lift pump will collapse fuel tanks, suck air past hose clamps, and draw enough vacuum to cause the fuel to outgas. I haven't had any issues.

The CAT filter mod is easy, inexpensive, and straight forward. If you extend your fuel filter change interval, it could even pay for itself.

I'd also like to note that my filters are ridiculous and unneeded overkill for most people. I installed them to deal with other issues with my fuel system and the local fuel supply, and now that my rusty fuel tank and fuel lines have been replaced, I could probably go back to stock filtration just fine. Millions of engines have driven trillions of miles on the stock filtration system without issue. Mach4 has gone I think a little over 100k miles on one set of stock fuel filters, by buying fuel carefully.

That is by far the biggest factor, buying carefully.

Edit:

Here's what and where I bought: http://www.dieselfiltersdirect.com/basic-turbine-series/griffin-gtb228-diesel-fuel-filter-water-separator

Don't think PP offers something similar, so shouldn't be competition. John took good care of me and I'm happy to send him more business.

__________________
617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap