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Fuel Problem

I love my Chevy Chevette!
Posts: 1
Joined: 04/14
Posted: 04/30/14 06:24 PM

I have a 1989 C4 corvette the car run out of fuel. once gas was placed back into the tank the car would not start, crank but not start. I changed out the fuel pump relay. still don't start.  I replace the fuel pump inside the tank still don't start. my next step is to change out the fuel pump fuse. do anyone have any idea as to what could be the problem before I have to second mortgage my house to fix this car.


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My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 04/30/14 08:37 PM

pick up the old relay...

look at the connector side.. see if you can bend the cover slightly to extract the internals of the relay...

you can now.. if you are careful to not touch it to anything grounded.. squeeze the contacts.. and make the fuel pump operate..

on another forum.. an oval fuel pump relay.. even new was found to be intermittent..

so... lets put the squeeze on it..  

the fuel pump relay and the 3 wire oil pressure switch are in parallel to operate the circuit..

the relay is computer controlled.  turns on for 2 seconds as soon as you turn the key on.. then comes on again as soon as you start cranking..

warning.. the green and white stripe wire is switched positive from the PCM.. Please DO not probe this with a test light. watch the bare frame relay function. i have seen that circuit burned out too many times ..

it burns out at one amp..  while i was on the way to a no start car..  the mechanic across the street who was not a fuel injection tech.. said.. i will get it started.. started probing stuff..  say.. whats that burning smell..  oh well.. you better wait for the other guy..  grease ball burned out the PCM..

so... squeezing the fuel pump relay.. will turn on the pump.. even if the key is off..

wait.. i have a diagram..

89Chevypickupfuelpumpwiring Zpsffd1102d

89 Chevy Truck Fuel Pump Relay Diagnosis ONE Tank Zps6acb887a

Gmfuelpumprelayoval Zps96e91037

this might be drawn wrong. and that will be my fault.. i probably did it about 3 am... E is out to pump...  A is the orange wire POWER... C comes from the ALDL G terminal and is the fuel pump prime connector.. only used by a GM mechanic.. used to prime the fuel system after a filter change..  

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My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 04/30/14 08:55 PM

oh... also check for power on PIN A of the fuel pump relay.. the ORANGE WIRE..

you will want to check the ORANGE wire to the oil pressure switch...

when you squeeze the bare frame relay when its plugged in. you should hear fuel surge thru the fuel rail if its quiet there. sorry . i live next to a freeway.. i cannot hear engines running sometimes..

you should also see power come on at the fuel pump fuse when you squeeze the relay...

let me know what you find...

i drop thru this forum 3 or 4 times a day looking for fresh posts..  

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My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 04/30/14 08:58 PM

post what happens..

there are grounds to check also.. one just past the end of the battery box.. and a positive connection on the other side with a bunch of fusible links coming off the stud..

87 C4 Underbatterygroundconnection

87 C4 Powerdistributionterminalblock  

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