OKay guys. I have a $6E. 350, 89 IROC, ZZ4 cam, vortex heads, headers. The car has been running great, just needing to find tune it. Took a 60 mile round trip open highway. Drove great one way. On the way back, I went to slow down in traffic to about 1800rpms, and car just died. Acted like it ran out of gas. Tank full. Car would not start. No gas smell. Let it set for a while, turn key on, car started. head on down the highway and it repeats the problem.

Happen to have the lap top with me (never travel with out it). ADLDed in and started dataloging next time around. When car started and I took off down the road, it showed in OL mode. According to BIN setting a HOT O2 stays in OL mode for 50 sec. Durning that 50sec, O2 volts slowly creeps up above 900mv and BLM is showing 150. As soon as the 50 sec timer goes off, CL mode comes in, the O2 sensor dives to 4mv for a while and starts to bounce around as normal. The BLM stays at 150 though. This time, I traveled about 10 miles in this condition. Holding steady BLMs at 150. Pulled off onto a side road and about 3 miles down that road at a slower speed, the car acts like it runs out of gas. voltage to FUEL pump is a steady 13v until the motor dies and the Oil pressure switch cuts the voltage off. Wait a while and it we go through it all again. Did it with mulitple chips, including stock THOUGHTS? (BTW, 3 month old BOSCH O2)

 

Sounds like your fuel pump is on the way out. How old is the pump? How many miles? Try tapping on the tank in the fuel pump area near the fuel pump the next time it dies to see if it will start hot. I have always seen them fail hot and work when cold.

 

How old is the fuel filter?

 

FP was my 1st thought. Replaced it and the filter about 3 years ago. It was a pain. In tank pump.

I guess I was hoping for an easier answer.

 

Wait on other to respond before dropping the tank. They might have a better diagnosis. And wait for the failure to happen again and try the tap on gas tank fix. That will let you know it is the pump. It could just be a bad wiring connection going to the pump to cause it to fail every once in a while.

Is that a GM pump?

 

I refuse to put non-GM fuel pumps in vehicles anymore,
have had to much trouble with the cheapo's
warrenty or not, I still got to pull the tank again,