i have a 87 t2, my mods are 3" down pipe with straight 3" piping to n1 muffler, FCD, Profec b @low boost min, and the walbro pump.. to add the motor had 160,xxx orginal miles. i was getting on it really hard on the freeway i probably hit about 8psi, and then i heard some knocking, then when i got to the toll booth the car sounded like it was running on one rotor, ans the motor was vibrating violenty. but the car did still ran ok and idled. when i got home i shut the car off it wouldnt turn back on.. however i was able to push start it. also no vaccum leaks or anything.

the irony of this was, the day before i had installed a walbro fuel pump..

what do you guys think blownmotor? or something else?

thanks,
al

 

Do a compression test FIRST! That will tell you.

 

Agreed. Lots of things can make engines run shitty, compression test or bust (no pun intended )

 

Same thing happen to me. Highway is bad for turbo rotaries. Especially a S4 with a dumb wastegate. All my friends pop motors on the highway. Anyway, yeah I did the same thing. My motor did the same thing yours is doin. Sounds like you popped your ****.

 

My friends 87 TII motor went in the sasme manner. You more than likely have blown the rear rotor. Go to the nearest rotory shop and have it checked first and start saving your money. I suggest you have it replaced with the s5 motor( better compression ratio).

 

why is the highway bad for turbo rotaries?

 

If your idle (or cranking) sounds like a galloping horse, then its dropped an apex seal.

I drove a car off the highway once and it idled "okay" but was impossiblele to start.

Pulling the two trailing plugs and cranking it with the egi fuse pulled told me what i needed to know.

The hissing was like a galloping horse.
le boom.

 

well i just did a compression test , and it appears the rear rotor is gone... it was 3 somewhat constant pulses no more than 30psi..

i know adding a fuel pump shuold decrease the chances of blowing the motor, but is there anyway the fuel pump could have attributed to the engine blowing? or was it just a coinsidence?

 

The Highway is bad becuase you build the most boost in 5th gear on the highway. Boost is dependent on load, and when your on the highway theres alot of it. I crept to almost 20 psi before I looked at the boost guage and reliazed what was going on. I was tryin to keep my eyes on the road. A Peak/Hold/Warning guage would have been nice to have then.

 

I think 160k miles on original motor probably contributed to it blowing. That's a lot of miles for a TII.
I'm sure it was just getting tired.