I put a 305 TPI on a 85 350 motor. I replaced most of the sensors, injectors, EPROM, harness, to speed desity. I got the motor to start, but idles a little rough, but when I open the throttle, it stalls right out. I am new to the TPI setup. I have put a TPi cam and lifters in the motor, I had the chip programed without emissions, and I have dropped a lot of money into this project! I hope that someone may be able to help me finally get me on the road. Also I am not showing any service light. Thanks for any help that you can offer. David

 

Double check the throttle position sensor, other than that, was that custom chip built correctly?

 

Have you checked your fuel pressure yet?

 

Also - did you change the injectors to the "normal" 22 pound per hour 350 motor injectors?

 

I burned the prom for him. I tested it on my 350 TPI motor on a test stand and it ran just fine.

His injectors are new 21lb/hr but the injector constant is still set to 22.1 lb/hr (he didn't have the new injectors until after I burned his prom). This is not a significant difference to cause the problems he's having.

The TPS is the only sensor he has that is not brand new.

David is out of town until Thursday, so he won't be able to check this thread until then.

Anyone else have some ideas?

David - I think you should check your fuel pressure at the rails. That was a good suggestion from above.

 

How's the fuel pressure?

 

Thanks for the replies! I did a a pressure check at the fuel rails, and found about 30 psi. I did a volume check, and it was low. I pulled the tank out again, and found that the pulsator between the pump, and the line, had a very badly worn seals in it. And the fuel was leakin past it. I removed the pulsato, and put a piece of high pressure line between the pump and the line and hose clamped it in, and the motror runs great!!!! Thanks again Dave

 

Awesome! With all the troubles you've been having along the way, it's really good to hear that the motor is running well. Looking forward to the possibility that you might drive to my place so I can see the finished product!

 

Does it stall then recover, or just die?

If it does stall and recover, sounds like a classic vacuum leak to me, unless I'm missing something here...rough idle when there shouldn't be is a good clue to that.

Of course, with as many changes as you've made, could be a multitude of things!

 

Ummmmm....he fixed it. See above.