Well I just bought this car today, its very clean has 132,000KM's on it, thats 80,000 miles. The one problem is that it only gets 45mpg and should get 55+mpg, any ideas to work with. I will go over it in the next few weeks, it has been serviced regularly.
Thanks Bob

 

Don't know that much about them, but have heard if they have EGR then the intakes get clogged with oily gunk.


phox

 

That is on the newer ones 99-03 I have one of those too. PITA to fix. the 84 doesn't know what EPA is, let alone EGR.
But thanks.
Bob

 

Told ya I didn't know much about them.

How bout valve adjustment? that many miles, it's gotta be due.


phox

 

Timing? I usually bump up VW's from .8mm lift to 1.0mm. I haven't done one as old as 84, but if it calls for .8, it might be worth a try. I assume it's a 1.6L engine?

 

Thanks tourqfan I was thinking the same. Will get it home Saturday and start to pick away at it. Was a good buy car is mint garage kept. No rust no dents.
Bob

 

actually it's the 97 and up tdi diesels that have the egr problems............. we "unlogged" my mom's 97 tdi a while back. After that fun experience we disconnected the crank case vent system and vented the block to atmosphere just like my cummins is and my dad made an egr block off plate to block the egr system


you're 84 jetta is a 1.9 right or is it the 1.6

my 93 1.9 turbo only ever got 45 mpg............my mom's tdi gets about 57

one thing I was told was that after about 100,00 miles the heat shields around the injectors get all carboned up and then they affect the spray pattern of the injectors killing mileage and power

it was sugessted to me that when I change my timing belt ever 160,000km that I take the time to pull my injectors and have them cleaned and rebuilt .........

all diesels should have the injectors checked, rebuilt every once in a while, my dad's toyota had 480,000km on it and it just didn't have the power it once had, so my dad pulled the injectors and had a diesel shop in prince albert do the injectors only charged my dad 50 bucks an injector to do them and that included new tips ....

made a huge difference his mileage bounced up from 28 to 36 mpg and the power difference was unbelievable, it runs like new again

 

45mpg is about right. I don't think you'll see 55mpg out of that motor. The 1.6L diesel engine is what the car has. The 1.6L engine was used up until 1992. 1993 was the first year of the 1.9L and the start of the EGR era.

 

When I worked at a VW dealer in the early 80's as the diesels first came out, the trick was "55 MPH for 55 MPG".
We had on customer that kept bringing his diesel Rabbit back because he said he couldn't achieve 55 mpg.
His stop & go commute added to his lead foot was the reason.
I took a test drive with him.
He was reving it high before shifting in town, & was running @ 70+ MPH on the highway.

 

I've had a few VW diesels and I would'nt have anything els in that class of car, about that time the cars where getting heavyer and 45 was about avg. but a lot depends on driving habits and maintinace, next back then I was going to build PU and I heard that the Canada's cars where 1.7l , 100 ccs more than here and the first turbos also you guys got . I just remembered that at a bio-diesel co-op meeting that one of the guys making his own fuel was getting 86 mpg in a mid 90s pasaat. We were bumping the timing for more power also , now I don't think I like the new ones becouse they added all the electronics, whitch in my mind defeats the perpouse of the diesel , keep it simple.

 

yes the heat shields on the injectors can cause problems. It is an easy fix just get the shield and pull the injector and shield the put the new one it. I did it on my 91. I only ever got 45 with my 91 ecodiesel. The turbos didn't get as good mpg's as the non turbos did. There are a few things you can take out of the intake to allow more air in.

mainer

 

Could also be that your turbo is "tired" as well...? Just a thought?

I would remove and clean those injectors right away, and check when the timing belt was changed, if in doubt, change it. Good luck!

 

I would advance the timing a bit if possible and make sure the cam is timed with the crank. The pulley isn't keyed and a person had to lock them at the correct spot while tightening the cam pulley. I would also check the boost on the turbo. On my dads the wastegate was opening up too soon so on the highway it was actually wasting fuel in some conditions instead of boosting. I set it at around 16 lbs now. Usually runs around 12. Seems to work good. He was always low 40's and is now mid to high 40's. ( 95 Passat )
I had an 86 Jetta also and it got 20 km/ litre consistently which is 56 mpg so I would say you are a little low.

 

I've got a set of the injector heat shields. I paid 25 bucks for them at napa. Make me an offer.

mainer

 

Well I have to thank you all for your help and advice. Drove the car 500 kms on the weekend, drives very nice way more power than I expected. Worked out the milage and was very surprised 56.7 mpg (imperial) that was mostly highway so with that being said I don"t think there is anything wrong. Did some asking around and most get 45-48 mpg in town. I may do the injector shields soon, the PO has a reciept for the timing belt being done.