Part throttle surging and wierd noise

[burn_your_money]

Like I said, it depends on your driving style.

I know it would have made a difference for me, but that's boring and not worth the 0.2L/100kms;)

[Rising]

I definitely could understand your logic jeremy on a strictly highway driving section. However my daily commute is entirely through towns and back roads. Lots of starts and stops. Having less fuel throughout the powerband makes it far harder to use as much fuel without just flooring it everywhere. Which I never do.

I definitely don't argue that I'm driving slower and accelerating slower and the total fuel used could be achieved with the fuel screw farther in. All those are completely true.. but having less fuel to play with seems to help me manage it better anyway.

Something in my mind says 100% or 80% throttle is bad. So I naturally never press the pedal that far. So turning down the fuel for me makes 80% throttle and below the equivalent of 70% throttle and below kinda. Idk if that makes sense...

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[Rising]

Okay so now I think I'm losing my mind. This issue seems to have partially returned with the part throttle surging since doing my timing belt and Gov Mod. It actually seems a bit more annoying this time. But I've triple checked all the bolts on the IP and none of them are responsible. So is it possible I did actually mess something up on the gov mod?

Also when it surges part throttle it's a serious increase in power... How can I make my diesel run like that all the time? Haha. Like is that a sign I need more advance? And why is this only a part throttle issue. Doesn't seem as noticeable (could just be me intending to go fast vs. Surprise) at WOT. EGTs definitely jump when it happens too but that could just be the revs...

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[burn_your_money]

Are you sure you shimmed the correct spring on the governor? Did you shim 1 or 2 springs?

[theman53]

Yeah it kind of sounds like he shimmed the intermediate spring doesn't it.

[air-cooled or diesel]

Okay so I've never done anything to my injection pump. The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel

as several other people quoted driving habits effect fuel mileage a lot, using 1/2 throttle to 2/3 throttle is best, 3/4 throttle should be your max throttle mostly; also keep your revs up(some) such as in 3rd in my 1.6na, I will at 1/2to3/4 throttle accelerate to 40 mph and in 4th up to 45 to 50mph and then get into 5th. keeping the revs up some with moderate throttle you will accelerate quicker and have less load on engine as a norm; there by saving some fuel or more. you may notice a difference in 1 tank and it can get better as you find the groove and the engine gets used to being treated in an easy manner.!

[Rising]

I just shimmed the longest spring(main spring I believe). Like 3 small washers... I read through through the gov mod sticky like 5 times first. So I read warnings against shimming the intermediate.

I was looking at pictures the whole time and didn't even take the governor all the way apart. I just pulled the snap ring and pulled off the main spring replaced with washers and out it back together.

Okay so I've never done anything to my injection pump. The biggest thing I've done besides setting the timing is adjusting the fuel screw and the idle set screw. (For reference I turned the fuel screw down a 1/4 turn to save some more fuel

as several other people quoted driving habits effect fuel mileage a lot, using 1/2 throttle to 2/3 throttle is best, 3/4 throttle should be your max throttle mostly; also keep your revs up(some) such as in 3rd in my 1.6na, I will at 1/2to3/4 throttle accelerate to 40 mph and in 4th up to 45 to 50mph and then get into 5th. keeping the revs up some with moderate throttle you will accelerate quicker and have less load on engine as a norm; there by saving some fuel or more. you may notice a difference in 1 tank and it can get better as you find the groove and the engine gets used to being treated in an easy manner.!

Good tips! I've been wondering about low vs. High rpms and shift points for economy. Engine does seem happiest under slightly elevated speeds. Not lugging it all over the place. . .
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[air-cooled or diesel]

there are a lot of other things that can help also with fuel mileage, takes about a day to maintain all these things; for instance engine oil, using a 5w-30 synthetic, if your car doesn't call for 5w-40syn specifically I like to run 5w-30 in mine(mk2). trans fluid, change every few years, syn fluid is beneficial. axles and things like wheel bearings keep greased, syn grease helps with mpg and part wear. I don't use syn grease currently in my cv joints, if you do make sure the syn grease specifically works in cv joints. rear wheel bearings the small outer needs to be packed and readjusted about 2x a year.(mk1!mk2!&mk3's).a good alignment, good tires proper pressure in tires, and even good working brakes all add to mpg and reliability.

[air-cooled or diesel]

ooh, though if you haven't had a full synthetic running regularly don't go and throw a syn in the engine, everything else its fine.
also a lot of the model cars the diesels the 5th gear is specifically designed for 55mph, the designers back then didn't see the 55mph law being changed, if you have one of these trans, I have 2 of them, even going over 55 to 56mph there is a drop in fuel economy.

[ORCoaster]

Melt those transmissions into a slug of metal and scrap them.  Do not let another experience a transmission designed for best economy at 55 mph.  Or only sell to old men that can't drive that fast anyway.

[air-cooled or diesel]

heheh, although the Trans's are very reliable, as long as you change fresh fluid every few years, and don't shift hard, even with some beating-on they can still last,, I have never had a vw trans go bad on me, as long as its like im not spinning tires or too much pop on the clutch, that's 10 or so cars I ve had over the years and I cannt call any not any problem with a trans(manual), , some were gas, I still have a gas a-c trans.

[Rising]

Good to know. Synthetic in gearbox is worth it? Why wouldn't I put syn in there? Didn't quite get that part of your post.

Any other ideas on this problem? Can't find anything else I did weird... Scared to pull pump back apart.. 

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[air-cooled or diesel]

maybe a couple of reasons not to use synthetic; 1 in an engine that has over 100k miles and hasn't used synthetic regularly its a no-no in a motor; 2 in a trans, I d use a trans flush, use properly and if trans fluid drains clear, you Can use syn in trans, if trans fluid drains dirty, refill with a good conv fluid. for wheel bearings it works pretty good. but im not assuming for you, if you don't know too much about syn lubes its up to your discretion, im a syn man and have been since my 1st or 2nd car. Valvoline for instance is average for the course, but you can find it easily in an automotive store, Castrol I figure is similar; for the really strong stuff, you cannt find in most stores, you ll have to do some research.

[Rising]

Okay so this surging problem has changed. Now it's a bucking  on and off problem whenever I'm in those rev ranges. It just starts surging on and off pretty quickly and makes it rather unpleasant to drive. I followed the pictures all along the gov mod thread and everything looked the same. I'm back onto or coasters idea about the sticky advance piston. Not really sure though. I could open the pump back up and post pics if you guys think that is the next place for me to go?



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[theman53]

I don't know...Are you sure you indexed the shaft correctly?