Problems after "Hutch" Mod - Fuel Pump Toast?

[yavorssj]

Here is the deal (2000 Excursion, 7.3, 200K)

A few weeks ago, I installed the Driven Diesel Regulated Return (set to 62 psi when warm). Ran great, smoother engine, a little extra power, etc...

This weekend, I installed the Driven Diesel pre-pump fuel filter kit (the "Hutch" mod + a Baldwin fuel filter and new line to the fuel pump). I cycled the key about 7 or 8 timed to prime the fuel system and started the engine. I ran rough for about 5 seconds and then seemed to smooth out, just like it did when I put on the regulated return. I gave it some more throttle, but then it seemed to "choke up," white smoke out the exhaust, etc... I then took it out for a drive, assuming it would smooth out, but it eventually died about 1/2 mile down the road. Called the tow truck...

Today, I partially dropped the tank to see if I pinched the new fuel line. Nope, it is fine.

I then got a fresh 3 gallon can of diesel and put in a temp line before the pre-pump filter. I ran the truck directly from the can, thinking that I incorrectly installed the "Hutch Mod" from Strictly Diesel and was restricting fuel flow. Result; same problem as before.

Next I put the temp line and can in right before the fuel pump, thinking that the new pre-pump filter might be restricting fuel flow. Result, Still am having the same problem.

It seems to idle fine, but starts to bog really bad/white smoke whenever the throttle is applied.

Is my fuel pump toast?

 

[ToMang07]

What is the fuel pressure under heavy throttle?

 

[yavorssj]

That is one thing I don't know since I do not have anyone to look under the hood when I apply throttle... Is there a way to add throttle from under the hood?

 

[ToMang07]

Have a phone or camera that can take video? Neighbor?

 

[yavorssj]

Oooohh... Android is being zip tied as we speak...

 

[yavorssj]

Youtube video is uploading...

 

[yavorssj]

Here is a link to the vid:

http://www.youtube.com/watch?v=v8IL1vJq_1w&feature=plcp

 

[lincolnlocker]

need to check the fuel psi while driving down the road at wot. with that kit it should hold rock solid psi no matter what you are doing unless you are feeding huge injectors on a small pump.

 

[yavorssj]

Sounds like a good idea, but I really don't want to have my Droid Bionic zip-tied under the hood while driving... Also, I am running the stock injectors and HPOP. No chip.

Well, since I am getting fluctuations like that without driving, I am thinking that I am not getting enough fuel flow. I isolated the fuel system before the pump, so I do not see how it cannot be anything other than the stock, 200k mile+ fuel pump...

 

[TARM]

Sound like you a fuel volume issue.


If everything was GTG before you installed the tank and filter kit then I think this gives you are really good place to start.

Check your filter head first. See if you actually have the hoses hooked up correctly based on the arrows on the filter head. IIRC Dennis uses a 4 port head unit. It should have come with at least 2 plugs. Each side has a port for flow in each direction. I have seen a fair number of people get this backwards as they think the flow direction is the same for both ports on each side.

I have seen people get the hook up on the tank sending unit wrong and hook the return to the feed tube and the feed to the return.

Make sure the none of the hoses got pinched when you reinstalled the tank.

Since everything was working fine after the RR for now we can assume it was all GTG.



The way to test fuel flow rate @ a given pressure without having to install a in cab gauge as that still does not actually give you a rate:

Pull the return line that going to the tank. Not sure how your kit is setup with bowl or bowl delete. Just pull the line from either the fuel bowl or the regulator that ends up going back to the tank. Put a hose on that you can dump into a 5 gal bucket. Put some measurement lines on the bucket for 1-4 gals. Start the vehicle up and time how long it takes to get a specific number of gals into the bucket. That will allow you to calculate the gph flow rate @ the 62 psi.. Should be 20 gph range or you should take 3 mins or less to put out a gallon into the bucket. There is such little fuel used at idle it should be a non-factor. Since the stock pump circuit cuts off after 30 sec if the engine is not running its easier to just do it running than the change up the wiring IMO.

Now the bosch pumps have a thermal overload circuit so if they get overheated they will go to a very reduced flow rate until the temp comes down. The real is if the siutation is causing cavitation its going to chew up that pump. Not that they are overly costly but still.

 

[yavorssj]

!

Yep. the filter head is hooked up properly (per the instructions that came with the kit. Also, I am on the correct tube at the sending unit.

Regarding having a lack of volume... I totally agree that this is my issue. I.E. ---> It idles fine, but bogs down whenever I place a demand on the fuel system. It simply cannot keep up...

When I pulled the fuel line off the downstream side of the filter and put in the gas (diesel) can and ran the engine, I kind of figured that I eliminated the new pre-filter and tank "hutch" mod work I had done. That, and I had partially dropped the tank to double check for a pinched line. Everything was OK...

This is why I am leaning towards the fuel pump. The new fuel line that came with the kit is 5/8 I.D. That is quite a bit of volume for the pump to fill and I figured that it would be sucking air for a while until the fuel filled the line. Maybe that pushed an old fuel pump over the edge and was enough to kill it after 200K miles of life?

Also, FWI ---> My RR kit is the Driven Diesel kit with the bowl delete and post pump fuel filter. Like I (and you) mentioned, it was running great until I decided to drop the tank and do the "Hutch" mod and pre-pump fuel filter.

Follow on question... Is the fuel pressure supposed to fall off like that when I shut down the engine?

Thanks for all the help so far... It is much appreciated!!!

Steve Y.

 

[TARM]

The 5/8" line is on the inlet side of the pump. I honestly do not understand why its used. The 3/8 is the restriction point. Either way once there is a prime it should be of none issue. I am beginning to wonder if something is up with the sending unit setup. Somehow its sucking in air or something is not allowing the prime. That could create the issue you are having. I hate the factory setup there. Rather than drilling and adding this and that IMO its better just to go with a new straight piece of tubing and bulkhead fittings just as the 5/8 kit does. All those clamps etc is just creating more points of failure IMO. Again the only time the pump would do any work would be the initial prime which is rare in a proper setup.

OK so I did not realize it was the bowl delete with post pump filter. So you are running a pre and post filter. Got it.

Here is the thing if everything was OK before the in-tank and pre filter mods unless it was just bad luck I doubt the issue is with the pump itself. Increasing the line size between pump and tank would not add any stress to the pump as a 3/8 line as its still not flowing any more than the 3/8 pickup. That is as long as its holding prime. Hence why I am wondering if something is up with the in-tank stuff.

BTW how much fuel do you have in the tank?

Check this. AT the pre pump filter (one between tank and pump) if you pull the line coming from the tank (5/8" hose) does fuel flow at a good rate from it? Hold it below the frame rail. If its not flowing well where its a small stream or dribbling out that's an issue.

If that checks out ok hook it back up and pull the line off the pump inlet how does it flow. Those filters should not cause any appreciable restriction that would be super noticeable. Less than 1 psi.

BTW I know it sucks having to pull the tank over and over. I have done my fair share.

If you have access to another fuel pump its a easy check to see if thats the issue.

 

[yavorssj]

Well, that is the thing... I temporarily put the new fuel line (downstream of the pre-pump filter) and ran the engine directly from a "Diesel Gas Can" and still had the same problem. I would think that, by doing this, I would have eliminated my tank work as being the cause of the problem since the problem was still present. In the process of doing this, I did what you mentioned and had good "drainage" onto my face and shoulder :thumbup:

Tomorrow, I am going to pull the line off the post pump filter and do the fuel flow test into a "Diesel Gas Can" like was mentioned previously. I will report the result...

I really appreciate all the help!!!

 

[Arisley]

You can remove the fuel pressure gauge, and plumb in a line long enough to hang the gauge on you mirror. Good for troubleshooting, looks ugly for long term use.

BTW, it also looks like you have some up pipe leaks.

 

[Strictly Diesel]

There seems to be some confusion here, the fuel line in that kit is 3/8", not 5/8". 5/8 wouldn't work without a 5/8" pickup tube and different clamps and fittings.

The filter should be a BF1212 with a water drain. Per step #31 of the instructions, it should have been pre-filled with fuel to help getting the system primed.

Based on the experiments that the OP has already done (moving the fuel pickup to an external can and bypassing the filter and tank), I tend to agree that this sounds like a fuel pump problem. It's very possible that getting the system primed again, particularly if the filter wasn't filled with fuel, may have just been too much for an old 200k mile pump.

I think that the video confirms that there is a volume problem (pump issue). With stock injectors, free-reving the engine shouldn't be dropping pressure that way.

 

[lincolnlocker]

also could pull the stock pump and look in the inlet side if the pump and see if any crap has built up on the mesh screens... could be plugged right there also....

 

[yavorssj]

Well, I went ahead and put in a temp fuel line and connected it directly to the inlet side of the fuel pump. I then put this hose into a gas (diesel) can... Next, I disconnected the pump outlet hose from the inlet side from Driven Diesel post pump fuel filter and put it in it's own can...

I then turned the key and let the pump run...

It turns out the pump is surging. The flow is not consistent and flows "normal" for about 10 seconds, drops off for a second or two, then comes back. It took 5 minutes to get 1 gallon in the can...

The fuel pump is dead.

Anyone have a spare:walkin:

Thanks for all of the help guys!!! This forum is great:rockon:

 

[Arisley]

Cool beans. You can get a Bosch replacement for pretty cheap. For your truck that is what I would recommend. I bet Dennis would have one to sell you.

 

[TARM]

If you are really in a bind I can send you mine. It had come in handy to drain my fuel tank.

It had about 70K on it.

Not sure it would be worth the shipping as you can pick them up at salvage yards for $20

 

[yavorssj]

Well, I got a new Bosch unit from Thoroughbred Diesel and am still having the same problem. The fuel pressure gauge is fluctuating all over the place (down to 65psi) when running at idle and I am still getting white smoke/severe bog at about 2,000rpm. :fustrate:

Any ideas? I am at a loss here...

At least the truck has a brand new fuel pump...