Schaef89Iroc5.7

I have a 1989 IROC with 5.7l that I drive about 1000 miles per year currently at 84000 original. I started to notice an issue this past summer that my fuel pump continued to run after shutting of the car and had to disconnect the battery to stop it. WHen reconnecting the battery, the problem would go away for a while. I replaced the fuel pump relay and it didn't fix problem. I drove the car to work to get it inspected and it seemed to run fine until I got in it to drive home and it would not start. Finally got it started and it would break up upon acceleration until it died. When it died, It would not start. Fuel level was very low so put gas in car and still nothing. towed car home, took a shot at maybe a bad fuel pump and replaced it.... No fix. Figured maybe it was ignition related and everything was original so I put in new distributor,coil, plugs, wires are good, egr valve was defective so replaced that and fuel filter. Still no fix. I will start car and it idles decent. when I go to give it gas, it barks nicely the first few times and then starts to load up and once in a while pop in the intake. I can get the rpm's to 3000 and hold it and I can hear one of the cylinders missing on occasion while holding it. Then if I shut car off, it would not even sputter to start. I can crank it and get nothing but the engine cranking.... Frustrated is not the word.... Looking for some advice and direction.... I should also say that fuel pump is now working right and seems to cycle like it should but does run longer than it used to. The car does not throw a service engine light. I also want to post that I found it ironic that when I pulled the return line off the sending unit of the tank, It drained almost all of the fuel out of the tank without using a pump or anything at all! Is that normal? Just trying to dig up symptoms....

305sbc

iTrader: (3)

That is frustrating and will probably require a good bit more troubleshooting to narrow down the problem.
I don't have a good idea yet, but I wanted to say that when you whack on the throttle the engine torques over counterclockwise, which can sometimes tug on some wires and cause intermittent problems. I would check the fusable links that go to the starter, the grounds on the back of the heads and some of the sensor connections.

If there is excess slop in your distributor shaft, then revving the engine can cause your rotor to rise up and press into the top of the distributor cap. You can normally see this as excess wear in the top of the cap. The distributor does need to have a very solid ground connection too.

What are your spark-plugs looking like? Are they getting fouled? Do they have the screw-on tips that are maybe getting loose?

Have you tested the TPS sensor or tried another sensor yet?

Does the problem go away if you disconnect your MAF sensor ?

Still lots to cover but you have to start somewhere.

Schaef89Iroc5.7

I have not really checked out any sensors yet. I also dealt with a problem a while back where when my car would get hot, the starter would not even click or turnover. I thought maybe it was a heat issue with the solenoid so I replace the starter because it was cheap and wrap it with a heat blanket...

Schaef89Iroc5.7

ok, more info I,m not sure about. I put a fuel pressure regulator on the fuel rail when I upgraded my cam a long tim ago. I had car running last night for about 20 minutes... When I went out to car today, the fuel pressure gauge was at 0. could I have leaking/bad injectors? they are original....