1990 tsi need some advise

[Jonmahar]

Ok so I'm looking at getting a 1990 tsi awd, the guy I'm getting it from doesn't know much about it. All he knows is that it has 42lb injectors in it, a bigger turbo, ostridge 2.0. And was told it has been rebuilt and "built". It idels good however bogs when driving. Not sure if the fuel pump has been upgraded. What should I look for and what do I need to do to get it running well. Also have stock injectors I can put back in.

 

[second_amendment]

first of all do a compression test. to see if the motor was built right. second go over all the essential parts. timing belt, balancing belt, fluids, spark plugs, spark plug wires. also go ahead check all the grounds lack of grounds create weak voltage to essential parts. check the pressure of the gas that comes out gas feed line. ( or just pull the old fuel pump and throw in a 255 walbro. oh yeah also check that the timing is proper. meaning all the timing marks line up with the cam gears and crank pulley.

 

[pirkeltooned]

TO add to what is above, put those stock injectors back in it. Set that turbo to a moderate level of boost compatible with OEM injector sizes, and put the tune to 100% stock. It is much easier to diagnose the health of that engine when it is running as designed. Once it runs like a dream under OEM conditions (and you figure out what "built" means for this engine) then start proper modifications with supporting modifications. It is always better to start with a solid platform which you know everything about, then to "fire from the hip" and to to diagnose a mystery machine. Just my .02