surging idle after refuelling with wvo

[Glenn Delwood]

Every time I refuel with wvo, I get a surging idle for a day or so. Anybody know anything about it?

[Mr. Flibble]

Every time I refuel with wvo, I get a surging idle for a day or so. Anybody know anything about it?

What sort of system are you running? Best guess with the information I have is something to do with the air seal for the tank.

[TardisDeli]

Likely due to crud in line or at a filter. cuz you stirred up the sediment in bottom of tank with refill. can u drain your tank. gently so u dont strip the screw closure, for which u might need teflon tape when you tighten it up after (without overtightening screw). maybe use another layer of filtering the wvo in future. are u single tanking, or separate tanking. if single, then you could be dislodging 20 yrs of crud, or the paint on the inside of the fuel tank. wvo is a strong solvent compared to diesel, so can loosen coatings on the inside of your diesel tank or in your fuel lines. or it could just be too thick now the weather has chilled the wvo.

I once had a chunk of crud inline just before IP, engine suddenly ran so rough I thought block had cracked...just unscrewed both lines in and out of IP and gravity drained into a jar, then put lines into a clean jar of diesel and turned igniton key a few times (NOT starting engine) to make clean fuel pump through the lines.

also a dirty air filter will do similar very rough idle issues. easy to replace that first.

PM me if more help needed, easier to talk on phone than type.
Cheers Christine.

[Glenn Delwood]

Two tank system with full return. Lately I have a rough start (it stalls if I don't give it some juice).
The system is only 4k km old.

[TardisDeli]

Thanks for the extra info.

Still suggest gunk in lines, especially because you say problems worse after adding in the new wvo...you have stirred up the old wvo. The filters inside your wvo filter can be very tiny (my donaldson's are smaller than a baby finger) so the least little lumpy wvo will cover the filter screen. for future, you can add an inline fuel filter, you know those little plastic barrels that are in the fuel line, but don't get those little 5 dollar ones, get a proper one ie for a mercedes 300, it looks like the cheap one but is not cheap...so you can easily clean it out before wvo gets to filter or IP.

Consider also if fuel too cold, now that the average weather has suddenly dropped. Maybe something not heating the fuel (ie wonder if the heated fuel filter not heating, so the coolant heat is the only wvo heat source). I have a temperature laser gun you could try, point at item to get instant reading, if you know what your system operating temp should be (I don't.... hmmm guess I should go take some readings now before I have problems). You can add diesel additives to the wvo, that remove water, increase cetane, prevent winter gelling, never add methanol or other water absorbers that are designed for gas.

Do change the airfilter, I know it seems WAY too simple, but it is a huge thing. You could try just removing the filter to see if starting is easier, but dont drive without filter in place.

Is all good when going up steep hills? I am wondering if IP filters clogged. So if you go up a known hill at your usual speed and foot-strength, is it sluggish / black smoke.

I use mostly PlantDrive system, so dont' know your system. Does their website have any suggestions? I know with PlantDrive that Ed Begley is super-knowledgeable even on Delicas, and often has great advice.

Idling on wvo is not good for most systems, so I switch to diesel when in heavy traffic. So, if you switch over (not purging, just switching) does the idling smooth out soon, mine does in 30 seconds-ish. If it doesnt change, then I am thinking IP (assuming you have separate systems until it gets to IP). As Mr.Flibble said, air. The rubber gaskets in the IP can die, allowing air. On mine, the air leak was noticed after a long parking time, when the system lost vacuum pressure so the fuel went back down into the tank, and didnt get pumped up enuf with the short pre-ignition time of fuel pump on.

Ohhh, just had a brain flash. If the roughness is when idling, are you suddenly running too many accesories and causing alternator to struggle to keep up, which leads to the idle speed changing as the engine works to increase the revs...ie air conditioning on to dehumidy the interior on rainy days, or the karaoke system on, or a new hd headlight system. On your system, does something happen with a new fillup of wvo ie it runs a special heater or filter, or does your fuel pump have to work harder due to gravity change .... or any odd thing that increases engine load (only noticable when idling, not noticable when accelerating).

Good luck with troubleshooting. I live near North Road, so probably not far from you.

Cheers Christine.

[Glenn Delwood]

I just changed the fuel filter and prime pump assembly. Seems to have fixed it. My veggie pump is still a bit fast but it started right up this morning.
FYI if you change the fuel filter pump and get a Hyundai/Kia one, unscrew the bottom part with the sensor connection so you don't have to solder anything to replace the new (not fitting Delica) connection.