I just bought a 85 Z28 305 Tpi has been sitting about 5 years It will Crank over but won,t start .When I putt starter fluid in engine it will start but dies Where should I start When I turn Ignition on I can,t hear fuel pump coming on I checked fuses thats on passenger side attached to over flow tank it was blown so I replaced but still didn,t start so I bought fuel pump relay just one still nothing happen .I checked for codes but there are none I bought a chiltons manual but it really doesn,t say how to test fuel pump.I took my test light and checked for power at the fuel pump block at back seat there was no power so at this point I need someone with more Experience than I have not to good at TPI,s so can someone please give me some Gudience Thanks Shawn

 

I also have an 85 TPI Z28. Since yours was sitting for 5 years, and when you turn the car to the on position you can hear the hum/whine of the fuel pump, that means it's getting power. Testing with your test light at the fuel pump, you should only see the test light light up for about 3-5 seconds when the key is turned on. Personally I would take the fuel filter off and replace it. I'd be willing to bet the filter is stopped up. But while you have it off, cycle the key to see if you have fuel flow when the pump primes it self. Be carefull as the fuel will shoot out pretty fast if the pump is working fine. once you confirm the pump is working and you have fuel flowing through the filter. Check for fuel at the fuel rail on the TPI set up. The service port is at the back of the TPI intake, just in front of the distributor on the passenger side of the engine compartment. Hook up a fuel pressure guage and compare your readings with the specs in the book.

 

On the fuel rail as described above, take the cap off the Shrader valve and push the pin and see if gas squirts out. I have a 85 too and on my 3rd fuel pump. Its a pain in the A** to replace. You have to remove the rear exhaust, disconnect the pan hard bar, shocks, lower the rear end, remove springs, disconnect all lines to the gas tank, remove gas cap and plastic collar and lower gas tank.

Rust in the tank will clog and stop the fuel pump operation.

There are a lot of write ups and pictures on how to do this. Just Google or search this site for more information.

 

Well i put new fuel pump in today drop rearend did it the right way before I bolt everything up I thought I would go ahead see if pump comes on and I did test it before i put back in tank and it worked ,so now I have it up in the car wiring is plug in I turned key on but I can,t hear pump coming on I have replaced fuel tank relays the relay up by headlights not sure what to do I haven,t had to many replys but I do apprciate your response I got the car sold to a guy waiting on me to get it runnning so not sure which direction to go now.Any help? thanks Shawn

 

Did you check and clean out any rust on the return line that goes inside the tank? mine was completely stopped up. Before I mounted the pump I used high Pressure air to clear out any debris in the metal lines on the pump side and return side. The type of pump I have is quiet and you can't hear it when the key is turned on. Are you getting fuel to the schrader valve?

 

No haven,t checked that yet I will work on it tomorrow for a little while I bought a Napa brand pump and asked the parts guy if it was good and he said it was there premium pump so I guess go ahead hook everything up check for fuel pressure so if I don,t have fuel pressure then what should I check.So there won,t be a constant 12v at the junction block by back seat I feel its not getting fire for some reason I have replaced all the relays friend of mine said it might be ECM is that possible and what does that entell?Hope I don,t sound Dumb I,m usually working On carb cars most of the time.Thanks Shawn

 

The fuel pump relay is the one right next the the power brake booster. The chiltons manual I have says it's on the radiator support bracket. They are wrong, thats the cooling fan relay. Just trace the wiring you'll see it's for the cooling fans. Above all, once you get the pump running you gotta make sure you have gas at the fuel rail. Check the schrader valve, at the fuel service port. If you have gas there, I would pull out #1 spark plug and see if it is fouled or wet with gas. If you have built or work with carb engines you know how important it is to be able to read your spark plugs. They can tell you alot on what is going on. As far as it being a spark issue, the ESC module right next to the fuel pump controls the spark signal. But at the same time with the HEI distributor you still have the ignition module (bananna clip) under the rotor button that is famous for failing on the HEI system. Do the basics first make sure the engine is getting fire and fuel.

 

One other thing I should mention, there is a fuel pressure switch and the sending unit for your oil pressure mounted at the back of the engine on top. (near the top of the bell housing, just to the right of the distributor, lots of wires may cover it) make sure the rubber cap is plugged into the two prong fuel pressure switch. This is a safety switch that only allows the fuel pump to operate when there is oil pressure present (cranking, starting and running). This is a biggie...you may have to use a jumper wire on the rubber cap to test.

 

i am having the same issue i have fuel to the rail and i have spark.the car wont start.if i spray gas in the intake it cranks up for a sec then shuts off.i checked for that sensor u are talking about and the only thing i found there was a plug for the oil pressure gauge.the car has a oil pressure gauge down by the oil filter.is the plug up top what u are talking about or no? i tried to feel the injectors to see if they were clicking but they wernt so i tested the 1st injector wire and it had power on both proms what could my issue be fixed by doing?

 

There is no low oil pressure shutdown for the fuel pump. The oil pressure switch acts as backup power for the fuel pump, in the event of relay failure.

Power at both pins at the injector is ok, doesn't surprise me at all. It's a batch fire system, so, the computer just grounds all four injectors on one side at once. Been a while since I have had to play with these though, so, not entirely sure just why the ecm wouldn't want to ground the injectors........ (which is what it sounds like is going on.)