uncontrolled revving

My son and I just installed a short block in his '88 turbo. The good news is that after a bit of twiddling, it started. The baaad news is that it starts revving uncontrolably. (5k within a few seconds). I suspect the pressure regulator/PR solenoid. Can anybody suggest a check on these components or an alternative fix?

My son and I just installed a short block in his '88 turbo. The good news is that after a bit of twiddling, it started. The baaad news is that it starts revving uncontrolably. (5k within a few seconds). I suspect the pressure regulator/PR solenoid. Can anybody suggest a check on these components or an alternative fix?

some things i would check.

- throttle cable, is it set right?
- TPS, often fail, ~$50 new OEM or free from a junkyard
- CAS, set right?
- coolant seals. remove coolant cap and check for bubbles on cold start.

Thanx, FCsilvia-
The throttle cable is in its default position and seems to operate smoothly. I assume that the TPS is the throttle position sensor, so that might be a good possibility to check. What is the CAS?
RGM

CAS is crank angle sensor. Is the revving steady at 5000rpms? That really just sounds like a stuck throttle. Double check your cable and throttle body.

MBTN-
Thanks. The revving is not steady at 5k. I suspect it would go to redline if we didn't kill it.
When making our first attemp to start it, I had to realign the CAS. Initially, it would not idle, then I rotated the CAS to its clockwise limit.

If it was TPS or CAS is it possible for it to remain a steady RPM at 5,000? If not then the throttle cable seems a likely cause...but im not sure...

+1 for TPS