Progress: I can now get fuel to the engine. Won't run long - 1987 740

Follow up to my saga of the replaced in-tank sending unit and no
start.

Up until now, no fuel to the engine, after I replaced the in-tank
sending unit, fuel filter, main pump.

Original problem: with original filter, original pump and replaced
sending unit - car died, would not start.

Well, today I removed the new AutoZone pump and put the old pump back
in. The car started for the first time in days!

But, the in-tank sending unit was disconnected (wiring) - so it ran
rough. I re-wired the in-tank sending unit and could not get it to
start again.

So, problem 1 was the new pump was not getting gas to the engine.
Putting the old pump in got gas to the engine.

Problem 2. Car started and ran a bit, but now it's wanting to fire -
getting a few revolutions of ignition, then dying out.

I disconnected the in tank unit again - but can't get a full start.
It's firing, but will not start.

Any thoughts?

 

Did you wire the Autozone pump backward? If you do that it will run but
won't pump.

Spray a bit of starting fluid in the intake and try it, if it starts up
for a moment then at least you know it's still just a fuel issue.

 

Thanks for all of the input.

A-zone pump was wired right and I saw it pump out the right end on a
bench test.

Here's a little more info and progress:
I have a 1987 car, & called FCP Groton asking about cross referenced
years for in-tank pumps and they said only a 1987 will work. Well, no
1987 cars to pull from in my area, so I grab a 1988 unit, snip off the
snap-on connectors for wiring in the trunk and hard wire it. Piece of
cake. Purple from the car goes to red wire to pump. Gray/white to gray/
white and brown to brown.

It's wired the same - red to pump on the positive post, gray/white and
brown to gauge, black comes back to ground. Thinking this morning I
would trash the sending unit and drive 70 miles to Dallas where a junk
yard says they have a 1987 unit, I put my 1988 unit in a bucket of
water and put 12v to it. It pumped water out just fine.

So, now it looks like the in-tank pump works, but I haven't checked
power from the actual wires that power the pump, so I don't know if it
works when I wire it up to the car.

That's where I am now.

Thanks!
Jamie

 

I posted under one of your other posts about fuses and the fuel injection
relay. The fuel injection relay controls power to both fuel pumps, but only
the in tank pump is fused by F11 in the fuse panel. That means the main pump
will work but the in tank pump will not work if F11 is blown. Is that a
possible culprit?

joe