I need some help with my 89 t2 s5 . The problem is that I have a new motor built by one of the best. The problem is it hauls *** in town but when I hit the highway and go for about 3miles at a constant rpm( cruise control) it will start to hesitate and loses all power and eventuly will die. If I let it cool down for about 10 mins then it will start and run great again but it will start up again. know it wont even make it around town anymore. Have replaced : computer, wiring harness, both coils, tps's, mass air flow, grounded the engine bay to help it, have checked all the ecu pins and everything checks out all volts correct everythings fine, no vaccuum leaks, fuel pressure is great, have replaced the injectors, compression is good when it is acting up, can't find it!!!!!!!!!!!!! PLEASE send my any idea's need help. No one knows what it could be.

 

How old is the fuel pump/filter?

 

Are the turbo heat shields in place?
You mentioned "cool down" - Is coolant temp running up?

 

No it never overheated and they are in place. It is a performance fuel pump and the filter is new. thanks for the posts, BUT I found out what it was. when the motor was getting hotter from a constant speed the bearings where starting to seize. The Brand new motor has to be rebuilt again. SUCKS.

 

No it never overheated and they are in place. It is a performance fuel pump and the filter is new. thanks for the posts, BUT I found out what it was. when the motor was getting hotter from a constant speed the bearings where starting to seize. The Brand new motor has to be rebuilt again. SUCKS.

 

No it never overheated and the shields are in place. The filter is new and it is a performance pump. Thanks for the posts, BUT I found out what it was. The bearings where starting to seize up. SO the brand new motor has to be rebuilt. This SUCKS.

 

Was the thermal pellet mod done to the rebuild? You saying the main bearings were seizing?

 

No it never overheated and the shields are in place. The filter is new and it is a performance pump. Thanks for the posts, BUT I found out what it was. The bearings where starting to seize up. SO the brand new motor has to be rebuilt. This SUCKS.

 

sorry it said that all the previous times failed

 

yep I have to send it back to the builder.

 

well, just to clarify where the places are we DON'T want to have our engines rebuilt, WHO'S the builder?

 

exactly how many miles were on the motor when you first found out it "hauls ***"?

 

more miles than he wanted for the break-in. I will keep the builder private. he is a good friend and he is on of the top 10 in the world. I have talked to other builders and they all say that once in awhile the bearings will fail right away. Thats my luck