This one's sorta got me stumped. After a few thousand miles, the driver's side injector starts spraying iregularly. I swapped the computer out, and have used both new GP Sorensen injectors and Junk yard injectors.

The only other thing of note is that the fuel filter does seem to clog up, but the tank was clean last time I dropped it to install a Walbro 307M. My fuel pressure is at 11 PSI, I set it with a home brew AFPR. The vehicle is a 1989 Astro with a 4.3L V6 TBI.

 

Is it happening just at idle, i believe factory spec is 12-13 psi, but i have found that the tbi's like a little more. maybe try turning up the pressure some.

 

Could be something stuck in the injector.

 

On the Astro vans the injector harness wire is run all the way to the ECM. The wire used at the injectors is special to resist the fuel in that area. F-body's usually have regular wire spliced in that then goes to the ECM harness connectors.

This wire being stiff can cause the connector pin to pull out of the ECM harness connector. And, cause it to lose tension in the barrel section. On your Astro pull the ECM and check the wires/pins at D14 and D16.

It is usually the end pin, D16, that pulls out or looses tension.

RBob.