thornton310

Fellow corvette enthsiasts
I have a problem with my corvette, my daughters boyfriend is a mechanic and helps a lot with my car, here is some info from him any help would be great. Thanks

i am a certified Ford technician .
have been working on vehicles for about 4 years
have solved extreme wiring concerns on fords and other vehicles but this is just melting my mind every day i cant pinpoint this concern soo.... here it goes...

1985 corvette automatic transmission
has a viper remote start alarm system installed
and thats about it.. everything else is just cosmetic.. mostly interior work.

he was having an intermittent long crank start then stall..
after cycling the key from off to on a few times you would hear the fuel pump turn on and then the vehicle would run fine start fine.

so i suggested for me to replace his fuel pump.
he bought the fuel pump.. and i was SUPPOSED to install it but when i call him to let him know i was on my way to replace it .. he told me that he had done it himself.

but came up with a new concern.

the car does not crank.. fuel pump does not turn on.

relays click in the dashboard, battery voltage is good. i am getting battery voltage to the hot wire at the starter... i read that the starter uses a case ground.

fuel pump harness side connector voltage..
3 wire..
black-ground
green-key on fuel pump ressure
green/orange?-key in start fuel pump pressure (colors are faded cant really tell what color it is)

good ground
good voltage key on
good voltage key in start.

only problem is i do not no the "description and operation" of the starting system and fuel delivery.

although my grounds and voltages are good.
as soon as i connect the fuelpump connector to the cars harness.. i drop all voltage ..
0 volts on green wire
0 volts on green/orange wire

its very strange.. i dont understand it at all.
as soon as i disconnect the two connectors i regain my 12 v on the 2 green wires..

its a carter fuel pump.. not an entire assembly .. just a pump.. he put it together.. i just wanted to go back and retrace his steps.
the onlything that was wrong were the 2 main wires the green ones..

they were switch so basically key on would have been key in start. and vice versa.. so i swapped them but nothing happened.

i have no codes in the system.
and i also tried bypassing all the safety systems and jumping the starter right from the hot wire to the solenoid and the starter did nothing..

well that about covers everything.. i really hope some one can help me figure this out with some basic understanding of the systems this car is equipped with.. maybe its just that im not understanding something.. or there could just be something extremely wrong..
i did think of these things being extremely concidental and multiple parts could be failing at a time.. it may have nothing to do with the fuel pump at all. i did look everything over.. and i corrected the things i found wrong.. but im compeletely lost..
we threw a "starter interrupt" relay and fuel pump relay at it.. did nothing.

the "starter interrupt"relay is located behind the message center..
any help would be awesome thanks!!!

AGENT 86

First off, jumping power to solenoid should have engaged starter, unless the battery connections are real poor.

Three wires to pump on my 86 are
black - ground
pink - fuel gauge sender
tan/white - 12+

The starter enable relay is behind the tell tale panel, but I wouldn't bother looking there, until you can make the starter run with a jumper wire.

0Paul Ruggeri

Sounds like a bad battery connection, voltage but little current flow.

car5car

About long crank starts:
Try to turn ignition on, wait 3 sec, off, on 3 sec then start. Is you have internal fuel leak (regulator) it takes some time for pump to build up pressure.
I diagnosed internal leak in my Cherokee to regulator which was in fuel tank.
You can also attach fuel gauge and see how fast pressure props after you stop engine. If you have pressure drop in 20 sec, you have leak.
I am pretty sure pressure should stay high overnight. If you have slow leak long start will happen in the morning.

jfb

Unplug the clutch safety switch (gear selector sw at base of gear shift if automatic) and jump the socket and try a crank.

rodj

Until starter confirmed working pointless checking anything else in starter circuit.
New starter time maybe?

YCarnut

Just like AGENT 86 said, your starter function should be your first priority. First, I would check the battery connections and then for 12V at the starter solenoid, at the front of the solenoid, top (big) terminal marked “B” or “Bat”.

If good, take a jumper wire and go from 12V+ battery post to the “S” terminal on the solenoid. The terminal is the small one on the right side (engine side) of the solenoid cover when looking from the front of the car.

If the starter cranks, then you have a problem in your start circuit, otherwise the starter solenoid, or starter needs to be looked at. Let us know what you find…