a little bit academic as i'm planning on going TD04l in the next month or two but anyway . . . .
i'm running about 24/25 psi on a Bosch pump and K14 turbo, the problem is this and seems to be a lot worse when running 100% veg (which i do),
when i'm accelerating hard and boost gets upto around 20psi car hesitates and coals out the back, if i accelerate steadily it more than often makes it to full boost without stuttering, however if i floor it it gets all constipated up the top end . . . .
pain in the arse tbh . . .also weird thing is it doesn't do it on Diesel, initially i thought it was struggling to get the fuel through on veg, but as i say it coals at high boost when it stutters,
does veg make thicker fumes? therefore forcing the wastegate open more easily? might sound crazy but that's all i can think of at the moment . . .
ideas welcome . . . .
Cheers, Matt . .
I get exactly the same thing, a stutter on full throttle when running SVO, but fine when on diesel.
I also thought along similar lines, that perhaps the thicker veg is not able to be pumped through quick enough.
I generally only get the problem in 5th gear, when the engine is under the most load.
It's the veg, struggling to pump it quick enough because it's thicker. I whack some petrol in and it helps.
yeah what i thought initially guys . . .but like i say, it coals at high boost, so that says to me that the fuel is getting through, it's just not getting combusted . . . . . . discuss . .
(24-08-2012, 08:28 PM)Mattcheese31 Wrote: [ -> ]yeah what i thought initially guys . . .but like i say, it coals at high boost, so that says to me that the fuel is getting through, it's just not getting combusted . . . . . . discuss . .
I think this is being caused by the fuel supply momentarily being interrupted as the pump catches up with demand, which in turn causes you to loose some boost. Then when fuelling is resumed you have a brief moment of lag while the turbo spools back up again, hence the coaling.
Although I may well be wrong, but that's what it feels like in my experience.
(24-08-2012, 08:39 PM)Toby Wrote: [ -> ] (24-08-2012, 08:28 PM)Mattcheese31 Wrote: [ -> ]yeah what i thought initially guys . . .but like i say, it coals at high boost, so that says to me that the fuel is getting through, it's just not getting combusted . . . . . . discuss . .
I think this is being caused by the fuel supply momentarily being interrupted as the pump catches up with demand, which in turn causes you to loose some boost. Then when fuelling is resumed you have a brief moment of lag while the turbo spools back up again, hence the coaling.
Although I may well be wrong, but that's what it feels like in my experience.
yeah i can accept that mate . . . . . . that was another thing that had crossed my mind also . . . . . . .so not much to be done then, thin it out with a bit of perv . . .hmmmmmm . . .increase internal pump pressure maybe? . . ..
Mine use to have a flat spot at 4k when on pure veg don't get that problem on the t25 oddly Just need to thin the veg a bit
interesting Jenks, i don't remember having this problem on my old DT with the T2 . . . . . . what turbo's are you guys running? . .
T2 myself, and the symptoms are definitely there when running 100% veg.
It would be useful to know which part of the system is struggling with demand.. I thought the Bosch's held a fair bit of fuel inside the pump itself?
I'm my ZX I have a T2 , running about 22 psi. It does this.
I'm my 306 I have and 11mm lobb pump and a T25 and it hates veg
it's such a shame because i bloody love running veg but this really boils my piss . . . . . would hate to think it's gonna do the same with the TD04 too . .
i keep reading various cummings forums in the hope of some "special" knowledge . lol . . . .wondering if higher rated delivery valves would make any difference as i've heard some mention on here as well . . . . is there not a particular restriction where the fuel comes in as well that needs boring out? . . . .
on a side note . . i put this thread on .net as well . . . . . . . . .how many replies? . . . . .not the one . . .
. .
(24-08-2012, 09:15 PM)Mattcheese31 Wrote: [ -> ]is there not a particular restriction where the fuel comes in as well that needs boring out? . . . .
It's possible to bore out the fuel supply banjo bolt.. Some members have done this, maybe they have some feedback..
(24-08-2012, 09:28 PM)Toby Wrote: [ -> ] (24-08-2012, 09:15 PM)Mattcheese31 Wrote: [ -> ]is there not a particular restriction where the fuel comes in as well that needs boring out? . . . .
It's possible to bore out the fuel supply banjo bolt.. Some members have done this, maybe they have some feedback..
yeah i thought that was the case, lots of people must have the same problem with veg . . . . .be nice to make steps towards sorting it . .
What I think causes it, like others say is that it can't draw it through quick enough but the hesitation is caused on some cars due to weak seals on the pump cause air ingress. I may be wrong though.
Mine did it on veg, but never on the diesel.
(24-08-2012, 11:14 PM)strictly_derv Wrote: [ -> ]What I think causes it, like others say is that it can't draw it through quick enough but the hesitation is caused on some cars due to weak seals on the pump cause air ingress. I may be wrong though.
Mine did it on veg, but never on the diesel.
yes i'm also inclined to agree with this too . . . . maybe a mini overhaul of the pump seals may be in order . . . .
I had same problems when running veg on T2, just used to thin it down in a barrel before putting in
I wouldnt start boring banjo out as the inlet and the return are equally matched for IPP, unless you have a guage on your pump i wouldnt start playing with the IPP either as this also affects dynamic advance and could cause more problems if pressure is already ok
You slightly lose a bit of power on SVO anyway so try making a mix of something like SVO pervv and noctane booster to get that little bit back
or maybe an inline heater for the veg to thin it even more before it gets to pump
CJ
I have bored out the banjo bolt and the bolt which bolts to the block. Abit to much boring went on so it snapped when I tightened it
This is whats called fuel starvation, lol. Your pump pressure is just dieing, but still has volume to inject, so timing is so retarded and just smokes to f*ck cos its so late
(25-08-2012, 10:12 AM)Dave Wrote: [ -> ]This is whats called fuel starvation, lol. Your pump pressure is just dieing, but still has volume to inject, so timing is so retarded and just smokes to f*ck cos its so late
right ok . . . . . . .anything to be done about it? . . . . apart from not running veg? . .
People have tried numerous times to fix this, it happens on diesel too if you're running enough fuel... Normally people have tried lift pumps, big fuel lines, different filters... Usually to no avail...
It's just the fact the pump cannot pull the fuel out the tank, through the filter etc quick enough... Ve pumps on Cummins etc are working in their perfect range of around 2750rpm, not 4500+...
As said as the fuel starves, the pump pressure falls off, it pulls off the dynamic timing, coals like f*ck due to the retarded timing, you'd think it's got all the fuel it needs due to the coal, but it's just the timing causing it...
i have this samw problem T2 lucus at about 14psi on pure derv. this thread has cleared the issue up a little
Ok, so this has been getting worse and today earlier on i went to pull out my carpark and she cut out half sticking onto the road . .
. . . . popped bonnet, pumped grenade and the little white doohicky on the side of the fuel filter housing pops right out! . .
so whips housing off and fixed it back up again and she's good as ever . . . . .not really hesitating up top either, so as mentioned by someone else in this thread seems air is the problem as much as anything, these setups just seem 10x more likely to draw in air if you're running pure veg, i had lots of shit a year ago with it when i started running veg, fixed the housing up, then the pump started leaking so fixed that . . . .just gotta keep on top of it i guess . .
so to conclude: make sure everything is airtight as fcuk and renew any seals if need be . .
Mine's doing this as well, but I think it's down to the fact that my boost gauge still hasn't turned up so it's standard boost, and I've only just started it on veg so it's still dredging crap out of the fuel lines and tank...
Ah but Matt mine did it on pure veg on the k14 once the t25 was on it stopped and I hadn't touched anything els.
(27-08-2012, 07:14 PM)Jenkosowls Wrote: [ -> ]Ah but Matt mine did it on pure veg on the k14 once the t25 was on it stopped and I hadn't touched anything els.
stop it you're melting my brain! . . . .
Hahaha sorry! Got it gov modded yet? You should drop by some time if not...