Hello there,
I have been a long-time reader of this forum but finally decided to join and ask for some guidance. I own a 1985 VW Jetta with the 1.6L turbo diesel (TD) engine. I love the car; and it has been pretty solid for the most part. Although; as it is getting older and with over 250,000 miles on the clock; I am noticing a few reliability issues creeping. I am interested in upgrading both for better reliability and performance without losing too much of the fuel economy I have come to love.
I have read mixed opinions about swapping to a bigger injection pump. Does it significantly improve performance; and if so; is it worth it for an engine with this many miles? Are there any downsides I should be aware of?
I have been considering upgrading the stock turbo. I am not looking to make huge power gains; just enough to give it a bit more pep on the highway. What are some reliable; bolt on options that would not require a lot of custom work?
I have seen some guys running intercoolers on these engines. Is it worth the effort for cooling; and does it improve longevity or performance enough to justify the cost?
Thanks in advance for your help and assistance.
There isn't really a bigger injection pump available.
The stock pump with the 9mm head provides all the fuel you need, what the engine can handle safely.
I'm not sure what turbo can be just swapped in and give you more power.
I like the VNT-15 turbo off the MK4 TDI diesels.
It bolts right up to the engine nicely but the rear motor mount gets in the way so it needs to be custom made.
Along with exhaust, probably the oil supply line and the return line.
It does hang low enough to allow better intake options though.
It will really bring your engine to life.
An intercooler couldn't hurt and should add some much needed air.
Proper performance mods will improve your mpg instead of hurting them.
assuming you already have a boost controller: first performance mod i would do is adding an intercooler, there are no downsides to it. It makes the engine run cooler which is very important for the reliability of an idi, it increases power by improving air flow with denser air, and it improves your mpg because the engine and turbo aren't working as hard thanks to the intercooler.
second thing i would do is either buy a giles performance pump, or if you're on a budget or brave you can modify your own pump by doing the governor mod and adjust fueling using the FAQ section of this forum.
Lastly would be to upgrade the turbo and i'd go for a small garrett wastegated turbo or one of the small holsets like an he200 or he201 which will offer better spool up and more flow than the stock k24 or garrett t3. the k24 and t3 can flow abolut 150-160hp worth of air which is around the point when a 1.6 becomes unreliable