Well I've put GM TBI on an older straight six in hopes of improving proformance; but having troubles getting it going. All the hardware is off a 89 Asto van and computer is 7747. Anyway when I start it up it will run for about a minute and die. Starts right back up and runs for about the same amount of time and dies again. Heres what I've replaced new 12-15 PSI pump, MAP sensor,coolant sensor,0xygen sensor,Idle air control sensor, Coil,ignition modules(put new HEI dist in).I have also had the TBI rebuilt by the local shop.I've also tried two diffrent computers and changed the program on the chip as well as used the factory one. I have a ALDL cable on order so I can diag with computer; but for now Its throwing a 33 and 42 code. The only two things I can think of to check for now is the fuel pressure (but figured it wouldn't start right back up if this was the problem) my other thought is the manifold vacuum pressure. I think I can buy an aftermarket 12 volt vacuum pump to take care of this if it is the problem?
Anyway any body else got any suggestions on what I might check?

Thanks
David

 

Is it idling during the time it is running? Could you keep it running by opening the throtle? Have you watched the injectors to see if the fuel is shuting down just prior to stalling?

 

Yes, its idling fast then smooths out after about 8secs. If I work the throttle I can keep it running, not sure how long. Tried to pull it out of the garage but kept dieing so I decided to put it back in the garage before it died for good. I'll try to watch the injectors later today.

thanks

 

Try going thru the proceedure for setting the min idle speed.

 

OK, the fuel pressure is good guess I'll stick with the idea of the problem with the Manifold Absolute Pressure since thats the code its throwing. I'll check that tomorrow. I'll also try to find the proceedure for setting the min idle speed.