Rob's DIESEL VW Polo Build thread

[robchalmers]

its not all that fun when the idle drops through the floor and the engine keeps dying every time you take your foot off the the throttle when you're not in gear!

luckily for me, it was something simple(with this thing there isn't anything complex on it!) I traced it back to the Idle bar lock nut coming loose and dialling itself down due to the vibration of the diesel lump.

quickly restored it to the right position and a factory correct 940rpm idle and a liberal dose of threadlock!!!!

all seems well now

[robchalmers]

My love of P+G is waning rapidly. On a full tank it seems to be hit and miss as to whether I’m gaining anything from it.
Taking a subjective point-to-point on the gauge of lets say 7/8 down to 3/4, in steady state running you get a consistent 60miles but with P+G I’ve managed 45. Then again between 5/8 to ½ it normally will do 76 miles yet with P+G I got 110. I thinks its all down to the rate of recovery in the pulse phase. Which is a skill and for me an incosistent one, I can’t argue it CAN help but My original idea for the car was to develop it do ‘anyone ‘ could drive it and get 50+ out of it. And from basic maintence that’s wholly plausable.

So…….. I’m going to ditch P+G :O

The next thing to do – is, I PROMISE, start modding

[320touring]

what? LAME!

I went from 468 to 508 using P&G on the Saab.. maybe as you say, the simple fuel system cant account for the loss of load?

or, alternatively, your pulse phases are too harsh- so you're getting very poor MPG for that ophase?

[robchalmers]

Thats what I've concluded, some times I get it right and the point to point on the gauge increased, some times i'd be a little to eager to 'recover' and It would soak up some extra derv.

saying that I past 585miles on this tanks and its only just got to the red!

If I'm going to measure the effects of mods I need to know there is consistent fuel usage in the A out of the A-B-A, hence ditch the P+G.

[320touring]

Originally Posted by robchalmers

Thats what I've concluded, some times I get it right and the point to point on the gauge increased, some times i'd be a little to eager to 'recover' and It would soak up some extra derv.

saying that I past 585miles on this tanks and its only just got to the red!

If I'm going to measure the effects of mods I need to know there is consistent fuel usage in the A out of the A-B-A, hence ditch the P+G.

why not look to get a consistent Pulse cycle- there's a certain point on the pedal in the Saab that gives good accel, but for not a lot of throttle- esentially a Sweetspot.

if you could be consistant then you'd have no worries regarding a-b-a testing

[robchalmers]

But the I'd have to train the 'everybody' how to do that as well

BTW another record tank with the P+G i did
594miles on 11 US gallons = 53.6MPGus / 64.41MPGuk

[euromodder]

Originally Posted by robchalmers

My love of P+G is waning rapidly. On a full tank it seems to be hit and miss as to whether I’m gaining anything from it.

I've tried P+G, but I can't seem to get the car to pulse at a fuel flow that would make P+G worthwile.

[robchalmers]

I'm starting to think that steady-state driving is a accurate indicator of efficiency. I know thats a bit of contraversial view, but imagine If manufacturers caught the dreaded 'upto' disease thats effected Broadband providers and start saying -"yep you can get up to 88mpg out of this" then mumbling under their breath " aslong as you use pluse and glide, with a tail wind with no passenger and less than a quarter of a tank"

thats why they all do a standard constant load dyno run to get their figures and thats where I believe we should beat them at there own game rather than changing the rules

[UFO]

If engines were efficient at the loads we actually use them, P&G would not be effective. And I'm not sure diesels benefit as much as gassers with that technique, maybe it has to do with the power-weight ratio of the vehicle.

[robchalmers]

Good point as the benefit seemed to increase lower in the tank.

going to attempt a grille block based ont the one from the last polo, tape covers the top grille and the outer ends of the lower grille. post-accident i know how to get the front off quickly..... which should make it easier!!!!