my 1.6 n/a sucks... 70mph top speed and 30mpg

[the4ork]

ok here is a few things i have done so far....

4 new glow plugs
new fuel shutoff valve (mine went bad)
new fuel filter
new air filter
20w50 valvoline
lucas gear oil
fuel addative a few times...
backed off the pedal govener screw where the throttle cable is
new rubber hydraulic fluid/fuel safe hoses on the injectors

only 30mpg no matter how i drive....

so then i loosen the pump and try advancing and retarding it a little... didnt seem to help power out any, actually i coulnt really notice too much difference that i can remember... only went like 2 degrees maybe. i marked the original setting and returned it...

when i played with the fuel screw i turned it in till it smoked pretty good, would leave a fog of black smoke behind me, not too terribly bad tho. noticed a difference in power wich was nice, but i didnt want to kill the fuel economy and didnt have an egt gauge so i kept turning it down little by little until there was a tiny bit of cloud from the tail pipe when revving it up, almost no cloud, just a very small puff...

and thats where she sits now.

but top speed with my foot mashed to the floor as far as it goes is 70mph after a very LONG run on the highway.

and if i start to pass a semi truck, i can get like 73mph, but when i get beside him and out of his draft and into the turbulent air, it slows me down to like 65 and then he passes me, and then ill be in his draft again and start to pass, and then hit the dirty air and he'll pass...

its freakin annoying!!!!

[vwmike]

You should be able to get at least another 10 mph out of that thing on a flat road. If your pump timing is off it may be too far retarded. Generally, if it is too far advanced it will be noisy and/or hard to start. A good place to start might be to verfy cam timing and use a dial indicator to properly set the pump timing.

Other causes of bad mileage may be crappy fuel, low compression, clogged air filter, bad injectors, etc.

[bryanbryan89x]

shiiiit, i had my 81 rabbit na pick-up loaded down with fire wood yesterday cruising home on the highway at 75mph no problem. I only had to down shift once...  
- 2.5 inch exhaust
- Gov mod
- 5 speed
- Cold/ram air
- K&n air filter
- pump timing set to 1.00mm
- I get around 35 mpg cruising on the highway between 70-75

[the4ork]

jeez, i wish there was someone around here that would help me set the pump timing... two shops around here know how to do it and they want $110 which would include pump timing set, new tensioner pulley and timing belt. i just dont want someone else touching my engine. i guess i need to buy the tools to do it....

hmm... i think maybe i will play around with the timing on it some more which direction is advance and retard? i can try advancing it a few degrees and take it on the highway and see if it helps out at all...

also my manual pump "choke" handle does absolutely nothing

and i have verified that the cable is working, and it does move the lever on the back of the pump. i have been told this retards the timing and makes the car easier to start when cold?

however if the car is warm (or cold) and you pull the handle or push it in there is no noticeable difference at all in the idle, sound, how it runs... even on the highway.

[Northboundtrain]

For $110 you can get the pump timing tool -- dial indicator and extension.  You'll also wand the Bentley manual for a good explanation of how to set the timing.  There are many posts on this forum regarding maximum advance -- 1.05 mm for a stock pump seems to be the consensus.  

I definitely wouldn't recommend the trial and error method.   The adjustment is very slight and you could easily over advance the timing and melt a piston.  

The cold start lever advances the timing to something like 1.35mm.  But from what I know of the pump's internals (very little actually) The pump adjusts itself back to the normal setting at higher rpms even if the cold start lever is accidentally left out.

[Asymtave]

As Northound says - the tools will pay for themselves the first time you use them.  And if you are going to tinker (who doesn't) then you will need them to optimize your vehicle.

The cold start mechanism is only relevant below 2000 RPM I believe.  After that the automatic fuel pressure driven advance mechanism takes over (on a properly working pump.)  

Before I tore into my fuel system last fall, the most I got on a tank of fuel in my truck was 51 MPG (ODO certified using mile marker posts on a long drive.)  I had to run to Akron a few times in a row and tore up and down the Ohio Turnpike at 70-75 and averaged 42 MPG in this mode.  

I have rebuilt my pump and injectors and an still running the fuel I put in there around Halloween so I don't have a new number.  I can't get black smoke no matter what so I think I have to increase the fueling (even though the original anti-tamper collar is still there.)  Timing is set at .85mm now.  Power seems comparable or down a little from before, and I can hit 75 pretty easily on a flat.  Hope this helps.

Eric

[moosiah]

Hi where is you ? is that lemoore Cal? or lemoore Ca ? the frankenbunny gets 43 at 65+ and climbs the Waldo grade at 60mph ......  

[the4ork]

yeah lemoore California... im about 30 miles south of fresno, in the central valley. SF is about a 3 and half our drive... ive driven the car up to fremont before to pick up an aba 16v and put it in the trunk. on the way up there going up the grade to get to gilroy from I5 i was chuggin at 40-45mph.... on the way back i said F' that and went all the way around the delta to get to I5 instead of going through the grade...

yeah my motor blows right now... im starting to wonder if its a combination of things... bad timing, maybe 1 bad injector? the motor does vibrate quite a bit, i wonder if one cyl is constantly missing... or maybe i have low compression in 1 cyl...

also... is it normal for a few days after an oil change (maybe 100miles or so) for  your oil to be really dark black already? my gassers dont do that... in fact they are never that black. and im using 20w50 syntec valvoline /w new mahn filter

unknown oil was ran in it when i bought it about 6 months ago. maybe i have a bad ring? diesel is getting in the oil? the suit from the combustion is making the oil black?

[Powjetta]

My jetta does a little better than that, I keep up with traffic no problem even on the hills.  I would check the intake path for any obstructions.  Do you have any idea how many miles are on the pump or injectors?  

I was surprised on my first oil change that it stayed clean for 2 - 3 days, I'm used to my diesel oil being all black right after changing it.

[the4ork]

well... 10 gallons... ran out of gas last night because usually i can get at least 300miles to the tank.... i got 283miles to the tank... and i had it filled a little more than full, it was topped off... so thats prabably like 10.5 gallons, and im getting horrible gas mileage...

i did give the fuel screw an extra half turn, so its smokes a little now, but at least i can do 75 and pass the semi's....

[wyldman]

Until you've timed one with the correct tools,you will never realize how far off it could really be,even if you've set it by ear,or by feel,and know what your doing.

[hillfolk'r]

iwas messing around the other nite on ebay,,theres a few places that sell a vw diesel timing "kit",,seen a few for around 50 dollars,but it didnt have a dial indicator,,,,some of the others did,,,kits seemed to have the camlock,pump lock,and pump mandrel that dialindicator goes in,and dialindicator,,,,watch out if indicator reads in inches,,you will need to convert,,,,,on ebay try searching under vw diesel vw rabbit vw tdi,,,iwas finding tons of stuff,,,for that 110$ you should be able toget the kitfor yourself,,,,,,,,,

[wyldman]

The cam locking tool isn't totally neccesary.A piece of flat stock or angle iron will work in it's place.

The pump locking tool isn't a big deal either,as you can use a socket that fits in the hole.

The pump adapter and extension can be picked up on ebay,or other places.Doesn't matter if your dial indicator is in inches or mm,it's easy to convert.

[andy2]

I've once used a 4.5 mm allen key to "lock" the cam(fits prefectly) and some chrome 11mm deep sockets(mastercraft either 1/4/,3/8" drive is what I use) will work well for the pump lock as well.

[hillfolk'r]

yea,,ive made the tools also,,or used sockets and stuff,but ya aint gettin round the dialindicator,,,,if someone cant make them,due to lack of knowledge,orlack of fabrication facilities(garage,lol),,,get a set from a supplier,,yea a 11mm 1/4 drive deep socket+flat stock will work,,,,have fun with it i say