Blue Bowtie

Is there a difference in the pressure output on the fuel pump of an 89 astro and a 94

I put a 94 4.6 in my 89 about 3 years ago, ran great for awhile then engine just mysteriously dies. It will restart imediately. Got to looking at the fuel pressure regulators, they are different from the 89 to the 94.
The tbi is of the 89. Could there just not be enough pressure?

For the TBI the FP should be 9-13psi.

For a VIN W motor it should be around 60psi.

What's the eighth digit of your VIN?

eighth digit is a z, but remember the engine is from a 94

You'll get a lot better response if you don't single out a member for your posts. A lot of very competent and capable members probably look right past these kind of threads, slowing your feedback. Moreover, whatever I reply with could be wrong, which would really hamper your efforts to correct whatever problems might exist.

Private Messaging works great for individual communications.

As for the fuel pressure, IIRC, the '89s used a TBI220, and therefore required a pressure of 11-13 PSIG. The regulator was mounted on the rear of the throttle body unit. The '94 probably used early (non-sequential) CPI, and had the regulator mounted under the upper plenum cover, right next to the control pod. The pressure of those systems should be more like 58-64 PSIG running, 61 minimum to start.

Good thing for you that CD Smalley already peeked in here and answered your questions.

eighth digit is a z, but remember the engine is from a 94

If you used the entire engine (and ECM) from the '94, it would have CPI. If you installed the TBI intake on the '94 engine, the requirements for the '89 would still apply.