EGR and lift pump

[gupster]

Hi all.
I am once again going to tap into the collective knowledge of the members. I have searched the forum for past posts but did not manage to find anything.
The engine management light comes on when my 2001 3.0 Nissan idles, but never when the engine is revving. I read an error code of 1003 when reading the flashing light. It points to the EGR, volume control valve. I have not bothered about it before as my intention is to block it off anyway. My feeling is that it has become sticky and not moving properly because it seems to correct itself, the light not coming on, when I do highway driving. However when I go off road, after a few days it starts playing up again. Has anyone experienced this and is it possible to strip and clean the unit?
The other question is to do with my Diesel lift pump. I broke the original one in the N. of Mozambique 2 years ago and could only find a Toyota pump that I modified to fit. However, that pumps pipes are smaller than the original one. Something like 8 mm compared to 10 mm. A few months ago, when connecting the diesel tank on the roof rack directly to the filter and running the engine at idle, I was surprised to see how fast the auxiliary tank on the roof emptied into the main tank via the return pipe. Would this be to stop the fuel returning to the tank from getting too hot and thus causing condensation? If I am restricting the fuel flow through the smaller pipes on the lift pump, would I be putting extra stress on the Diesel pump itself and perhaps get premature wear? What replacement lift pump would be recommended or should I get the original one? I did try once but although the pump looked basically the same, it had 2 extra smaller pipes on it as well.
I always think the more we know about our trucks the better and I thank you in advance.
Hi almal.
Ek weer gaan om toegang tot die kollektiewe kennis van die lede . Ek het op die forum vir die afgelope poste , maar het nie daarin geslaag om iets te vind .
Die enjin management lig kom wanneer my 2001 3.0 Nissan luier , maar nooit wanneer die enjin is revving . Ek lees 'n fout kode van 1003 wanneer die lees van die flitsende ligte . Dit dui op die EGR , volume beheer klep . Ek het nie die moeite oor dit voor as my bedoeling is om dit te sluit in elk geval . My gevoel is dat dit taai en nie behoorlik beweeg word omdat dit lyk self reg te stel , die lig kom nie , toe ek die snelweg ry . Maar toe ek gaan off-road , na 'n paar dae begin speel dit weer . Het iemand ervaar het en is dit moontlik om die eenheid te stroop en skoon te maak?
Die ander vraag is om te doen met my Diesel lift pomp. Ek het die oorspronklike een in die N. van Mosambiek 2 jaar gelede en kon net vind 'n Toyota pomp wat ek verander om in te pas . Egter dat pompe pype is kleiner as die oorspronklike een . Iets soos 8 mm in vergelyking met 10 mm. 'N Paar maande gelede, toe die koppeling van die diesel tenk op die dakrak direk na die filter en die bestuur van die enjin idle , was ek verbaas om te sien hoe vinnig die hulp tenk op die dak leeggemaak in die hoof tenk via die terugkeer pyp. Sou dit wees om te verhoed dat die brandstof terug te keer na die tenk uit te warm en dus veroorsaak kondensasie ? As ek die beperking van die brandstof vloei deur die kleiner pype op die lift pomp, sou ek om ekstra stres op die Diesel pomp self en miskien kry voortydige dra? Wat vervanging lift pomp sal aanbeveel word of moet ek die oorspronklike een ? Ek het een keer probeer, maar hoewel die pomp gekyk basies dieselfde , dit het 2 ekstra kleiner pype op dit so goed.
Ek hoe meer ons weet altyd dink oor ons vragmotors beter en ek dank u by voorbaat .

[Peter Connan]

Barry, I know nothing about EGR.

But about the lift pump: I very much doubt that changing from 10mm to 8mm for a short distance of piping will make a noticeable difference, and there are other factors here that might make more difference. I also don't know why Nissan went for 10mm lines when just about everybody else uses 8mm. Even fairly large petrol engines use 8mm without problems. Perhaps it's because the big petrol engines use the same fuel lines.

Yes, 8mm will have a little bit more friction than 10mm, but on the other hand the momentum of the fuel in an 8mm system will be less than that in a 10mm system. Dragsters use relatively small fuel lines for this reason.

But the more important question is what the delivery (both pressure and volume) of the Toyota pump is compared to what the original pump supplies? This is more likely to cause problems than a reduction in pipe size. But my gut feel says that if the lift pump comes from a vehicle with similar engine size and fuel consumption, you should be OK?

[Stefan]

Hi Barry, does the light come on again after you've reset the code? Is the EGR a serviceable item?

[gupster]

Hi Peter and Stefan. Unfortunately the replacement lift pump was not in a box so I did not get any details of it except that they said it was the replacement one for a Toyota Hilux. I guess that could mean anything from a 2.5 D to a 3.0 D. I too cannot see why a 8mm pipe would not be sufficient to do the job and not be an issue, its just one of the things I worry about when being in remote areas. Later I looked at a Nissan Ternano lift pump and that was also 8 mm. Peter you added another dynamic I had not even considered with regards to pressure and volume. I have now decided to invest in the Nissan replacement and thus put the worry out of my mind.
Stefan the light comes on almost straight away after resetting the code. I even tried disconnecting the battery for 12 hours and resetting but it still comes on. 1003 is a error code that resets the management light off when you switch off the engine but stores it in the ECU memory. If I restart and keep the revs above 1000 and drive straight away the light stays off until the revs drop below 1000. I am hoping the EGR is servicable. I will tackle it in a couple of months time and post what I find. I must remember to take some pics too.
Thanks