Possible fuel starvation

[skid]

I know this is an old post sorry, I have read many places about "the tiny thimble size filter" Just replaced my filter and added a water separator type one with a glass bowl as a pre filter to the standard one, I have been experiencing when I really give it berries up a hill from around the 2K-3K rev mark it hesitates as though it is starving of fuel, But if I rev it when I'm parked, it revs out well up to the 4K mark with no hesitation. I followed the instructions here today to try and get the "the tiny thimble size filter" out but it appears there isn't one in there as I can poke a bit of wire about 2-3 inches down the hole. I've only owned the truck for two months, it was originally a 200 GU 3Ltr but when the guy blew the motor up he put a 1990 silver top in. When I was getting the air con re-gassed 2 weeks ago the guy made comment that the injector pump looks new, I've read that some of the later model cars don't have that tiny filter, if the pump is in fact new could it be a case of if or when it was reco'd that they never put the tiny filter in? Any advise or suggestions would be greatly appreciated....

[ricster]

That mesh filter you are talking about is "a nice to have but not really necessary" ( in my opinion ). 

The symptoms you are getting, to me sounds exactly as you say...... fuel starvation. Rectifying this problem can be done various ways. First way is to install an inline lift pump to suck the diesel from the fuel tank to the injector pump. The injector pumps on the TD42's is a low pressure pump and these pumps are usually turned up to almost max when a turbo is fitted. the injector pump then battles to suck enough diesel to the injector pump and you land up with starvation symptoms. You have also added an extra filter, which is going to make getting diesel to the injector pump even more difficult. This is where the inline lift pump will help fix this problem.

The second way is to revert back to the standard diesel filter. I'm in South Africa, so I don't really know the quality of the diesel you are getting or using. The standard setup works very well. I have been to a few countries neighbouring South Africa and had to fill up with questionable fuel a few times, but before the next fill up after each "dodgy" fill, I open the "tap" on the bottom of the filter and drain out a few milliliters into a small bottle and check if there is any water in the diesel.

The third way, and this may not necessarily be the fix, is to have the pump serviced. The pump may look nice and shiny new, but the internals may be worn and therefore you are not getting the suction to get the diesel to the injector pump. 

To sum up....  I'd just put the lift pump in, and leave the filters as is.

[Rumcajs]

What he said, if you have added extra prefilter then it is prudent to install additonal electric lift pump with sufficent capacity.

Walbro FRB-22 or FRB-13 should suffice and good news they're through flow so don't restrict the flow when not in use/out of action.

Just make sure the existing injectors spill line returns to fuel tank not the suction line on the injection pump (normally under negative pressure due to lift pump being a part of IP) otherwise you'll have issues. FRB22 is capable of delivering 8-11 psi positive pressure which is/should be perfect under large load/demand but check max pressure rating for the IP.

I know that a lot of aftermarket Diesel specialists fit FRB13-2 (5-8 psi)to assist rotary injection pumps on older diesel with good results. I have that one too but now considering the bigger FRB22 series.

Regards

[skid]

I already had the feeling of fuel starvation before I added the other filter and replaced the existing one, putting the foot down I was lucky to get 3000RPM out of her

Edited October 21, 2015 by skid

[ricster]

"Just make sure the existing injectors spill line returns to fuel tank not the suction line on the injection pump (normally under negative pressure due to lift pump being a part of IP) otherwise you'll have issues. FRB22 is capable of delivering 8-11 psi positive pressure which is/should be perfect under large load/demand but check max pressure rating for the IP."

I have been toying with the idea of fitting a lift pump for ages now, but time is my enemy and the Iron Maiden runs real sweet at the moment...... but when I get the itchy sensation and do do it, I like to look at the pictures more than reading how to do a lift pump install, especially the spill line return as quoted above.

So Rumcajs..... get the camera out and help a brother out halfway across the world.....hahaha

PS.... Please before the Rugby World Cup finals..... I don't want any animosity to creep in when we win ......hahaha  

[skid]

Bought a little pump today and mounted it between the 2 filters, will see if that helps..
4-9 Psi 100 LPH Fuel pump Petrol Diesel Ethanol Bio Diesel

[skid]

Took it for a run and for first K or so didn't notice any difference, then after that freely rev's past 3K, will see if its just my imagination or not in time, but it seems the little pumps is doing something....

[Rumcajs]

There ya go, now stop dicking around and fit some decent lift pump like I mentioned earlier.

Cheers

[Rumcajs]

"Just make sure the existing injectors spill line returns to fuel tank not the suction line on the injection pump (normally under negative pressure due to lift pump being a part of IP) otherwise you'll have issues. FRB22 is capable of delivering 8-11 psi positive pressure which is/should be perfect under large load/demand but check max pressure rating for the IP."

I have been toying with the idea of fitting a lift pump for ages now, but time is my enemy and the Iron Maiden runs real sweet at the moment...... but when I get the itchy sensation and do do it, I like to look at the pictures more than reading how to do a lift pump install, especially the spill line return as quoted above.

So Rumcajs..... get the camera out and help a brother out halfway across the world.....hahaha

PS.... Please before the Rugby World Cup finals..... I don't want any animosity to creep in when we win ......hahaha  

There are 3 possible system set ups for TD42. For two of those there is no need to modify the how the injectors spill line is routed and for the last one you just need to make sure that spill line points to fuel return line and not back in to intake side of the pump. You have to look at your system as I don't know which one you have, courtesy of Nissan making things different every shift!

So if yours resembles type 3 or fuel spill line is connected to intake line on the pump you must re-route it to fuel return line if you install additional lift pump.

I had to do it on mine but that's ZD30 abomination on VP44 injection pump see bellow:

I fitted Walbro lift pump in the engine bay, ( Mr NIssan has pre-made some mounting holes with threads there so I couldn't resist) you can hear it inside with stereo off  when engine (everytime I have a passenger with me they wonder what is that rattling oscillating noise?) is idling which I like, lets me know it is working. I have extra manual switch in the centre console to turn it off if I choose otherwise it is powered of the ignition signal and if I could be bothered that much I could also fit inertia safety switch in the circuit so it will kill the pump in case of accident for added safety.....

If I mounted it on rubber blocks then it will probably be even less resonating through the body. I'll be going bigger FRB22 soon as I think VP44 can handle more (up to 14 psi is reference design) pressure and it is actually better for extra power output.

 

Edited October 22, 2015 by Rumcajs

[skid]

Will put a quality pump on when funds allow

There are 3 possible system set ups for TD42. For two of those there is no need to modify the how the injectors spill line is routed and for the last one you just need to make sure that spill line points to fuel return line and not back in to intake side of the pump. You have to look at your system as I don't know which one you have, courtesy of Nissan making things different every shift!

So if yours resembles type 3 or fuel spill line is connected to intake line on the pump you must re-route it to fuel return line if you install additional lift pump.

I had to do it on mine but that's ZD30 abomination on VP44 injection pump see bellow:

 

Mine is a TD42 engine its self is a 1990 silvertop So old school

[ricster]

Thanks !!!

Well mine is definitively "Type 1", which looks like the simplest setup too.

Would it be better to fit the lift pump between the tank and the filter or between the filter and IP. I presume the pump is strong enough to suck the fuel through the filter, giving the benefit of sucking filtered diesel instead of any possible tank gunk floating in the tank depths. My only concern this way is that as the filter over time blocks up ( I've never had one do that...... yet ) will the pump get damaged causing issues with worn out bits of lift pump getting into the clean diesel flowing into the IP

[skid]

Mine looks like type 1 also, cant beleive how much difference this 30 dollar lift pump has made...

[Rumcajs]

Thanks !!!

Well mine is definitively "Type 1", which looks like the simplest setup too.

Would it be better to fit the lift pump between the tank and the filter or between the filter and IP. I presume the pump is strong enough to suck the fuel through the filter, giving the benefit of sucking filtered diesel instead of any possible tank gunk floating in the tank depths. My only concern this way is that as the filter over time blocks up ( I've never had one do that...... yet ) will the pump get damaged causing issues with worn out bits of lift pump getting into the clean diesel flowing into the IP

You want to push the fuel through main filter, if you are concerned then fit additional sedimenter like CAV or like ones from Racor before the additional lift pump.

Cheers

[skid]

How much do the racor cost?

[skid]

By passed everything as you said, for first drive sinking the boot in it coughed wrc for the first hundred yards, think that might have been a little air, then doing a large lap of the block can easily rev it out to 3200RPM, have now put everything back together so primary filter then lift pump then factory filter. So it looks like my problem might have been a clogged factory filter to start with.. Wasn't game to push it too hard only revved up to 3200RPM but felt like I could push it further... thanks for the suggestion, have not got around to checking if there is a thimble filter in the actual  pump. will get around to it during the week...

[ricster]

Excellent news!!!

[ricster]

I just found out something new..... well not new, but definitively new to me !!!!

The VE pump has a fuel pressure regulator !!! I was under the impression that this was only on a common rail motor, but nope..... the TD42 pumps have 'em too.

On the South African Patrol forum, there is a thread about similar issues, and although some of the comments are in Afrikaans ( one of our many official languages here ) It may be interesting to see these pics. Google translate doesn't really work too well with translating the Afrikaans into English, but basically the seal deteriorates and allows air into the system, and also messes with the fuel pressure, so making the lift pump basically hide the symptoms and not really solving the problem. There is some references to Youtube videos too.

http://www.patrol4x4.co.za/viewtopic.php?f=44&t=5794&start=20#p66344

 

[Talou]

Hello @Rumcajs,

Sorry to bring that back.

I do have a ZD30 direct injection 2004 and would like to add a lift pump.

If I understand correctly, you do it like this?

Regards,

Vincent;

[Rumcajs]

On 11/22/2022 at 12:43 PM, Talou said:

Hello @Rumcajs,

Sorry to bring that back.

I do have a ZD30 direct injection 2004 and would like to add a lift pump.

If I understand correctly, you do it like this?

 

Regards,

Vincent;

Hi,

Yes I do have it kinda like that, I've added fuel cooler to the return as well but can't really make/notice the difference. When ambient temperature is 50C I've seen fuel temperatures reaching scary 65C.  Heat is VP44 injection pump killer ( you probably need fuel heater not the cooler). I kinda wish that I've obtained bigger lift pump e.g. Walbro FRB22 as on WOT the fuel pressure drops to almost negative with mine FRB13.2.... advantage with Walbro over Carter is that these reciprocating pumps are flow through design so on a few occasions I forgot to turn mine on the IP internal vane pump still delivered. 

Regards

Edited November 24, 2022 by Rumcajs