Testing Fuel Pump Pressure - HOW? WHERE?

[DOCTORBILL]

In a previous thread, DieIntermim (Blake) said the following:

"When my pump was failing the sound of the pump that I was used to hearing had changed in pitch.
Starting was fine and the idle was acceptable, however when I pushed the throttle for power
the engine would lose almost all power and sputter.
I found that if I pumped the throttle and mashed it down, the engine would regain power.
Eventually this pumping of the throttle for power came to an abrupt end and I found myself sputtering
towards home in 2nd gear before it failed totally.
I had thought my pump was fine because when I measured the pressure it was correct, but I was in error.
In order to really test the pump I should have taped my guage to the windshield and went for a drive.
Had I done this I would have seen that the pump could not supply the volume required when
the engine was under load and needed a greater volume of fuel."

This is what my engine is doing now - only it won't idle!

Where would you put the tube (small rubber tube?) to do that?
What kind of guage? Where do I get one?

Tape the guage to the windshield - The stated pressure range
in the Chilton Manual (p 5-15) is 25 - 33 lbs. That is a lot of pressure!
Would I need a "T" pipe joint to do that? Where is the fuel line in the
engine compartment - and is it a rubber hose?

This sounds like a good way to get my arse burned to death, also!

Before I dump $140 labor to have the pump and screen replaced
(I paid $220 for them - but they are returnable!), I'd like to prove
that my problem is the fuel pump.

See my Post of 5:35 PM 12-24 in
"How can you test continuity with an ECM and O2 Sensor?" for the
symptoms. I replaced the MAP Sensor and the Check Engine Light
says 'all is well my friend...'. So it must be the Fuel Pump
that is failing....

DoctorBill

PS - Blake! (DieInterim) Are you still alive?!

[unbe]

Originally Posted by DOCTORBILL

In a previous thread, DieIntermim (Blake) said the following:

"When my pump was failing the sound of the pump that I was used to hearing had changed in pitch.
Starting was fine and the idle was acceptable, however when I pushed the throttle for power
the engine would lose almost all power and sputter.
I found that if I pumped the throttle and mashed it down, the engine would regain power.
Eventually this pumping of the throttle for power came to an abrupt end and I found myself sputtering
towards home in 2nd gear before it failed totally.
I had thought my pump was fine because when I measured the pressure it was correct, but I was in error.
In order to really test the pump I should have taped my guage to the windshield and went for a drive.
Had I done this I would have seen that the pump could not supply the volume required when
the engine was under load and needed a greater volume of fuel."

This is what my engine is doing now - only it won't idle!

Where would you put the tube (small rubber tube?) to do that?
What kind of guage? Where do I get one?

Tape the guage to the windshield - The stated pressure range
in the Chilton Manual (p 5-15) is 25 - 33 lbs. That is a lot of pressure!
Would I need a "T" pipe joint to do that? Where is the fuel line in the
engine compartment - and is it a rubber hose?

This sounds like a good way to get my arse burned to death, also!

Before I dump $140 labor to have the pump and screen replaced
(I paid $220 for them - but they are returnable!), I'd like to prove
that my problem is the fuel pump.

See my Post of 5:35 PM 12-24 in
"How can you test continuity with an ECM and O2 Sensor?" for the
symptoms. I replaced the MAP Sensor and the Check Engine Light
says 'all is well my friend...'. So it must be the Fuel Pump
that is failing....

DoctorBill

PS - Blake! (DieInterim) Are you still alive?!

What year and type of fuel delivery system do you have?

[DOCTORBILL]

Originally Posted by unbe

What year and type of fuel delivery system do you have?

It is a 1993 3 cylinder, 1.0 L Throttle Body system with an in-tank
electric fuel pump.

I am going to test this thing first (and easiest) by checking the voltage
going to the pump at the connection under the seat.

What bothers me about this situation is that I was able to drive the
car 30 milles with the MAP Sensor disconnected. This was before I
found a MAP Sensor replacement.

If the fuel pump were failing, then disconnecting the MAP Sensor could
not make it miraculously work fine again.

I have to pin down where this problem resides.

Is it in the pump itself or in the ECM?

I just now thought that maybe what I should do to check the pump
itself is to supply it with 12 volts directly from the battery. If I can
drive the car that way, then the ECM is cutting it off from there.

AND, then is when I should check fuel pressure. If I isolate
the fuel pump from ECM control, I can check it out by itself.

I just need to know exactly how Blake hooked up a pressure gauge
to the fuel line.

DoctorBill

PS - today (Christmas) at dinner, my brother-in-law suggested that
I get away from this 'in-tank-fuel-pump' crap by installing a 12 volt
external fuel pump from another make vehicle. Interesting idea.....

[unbe]

according to my Haynes manual
1)relieve fuel pressure
2)remove air cleaner
3)remove fuel feed line from throttle body and T in a gauge,clamp line securely and check for leaks
A couple of other things that come to mind are,have you changed\checked your fuel filter?Did you resolve the intermittent low voltage to the MAP sensor issue? I wonder if disconecting your MAP sensor puts it into open loop wich maskes the original problem.An inline would have to be wired in a manner that it would shutdown in a crash,and the ones I've seen were used in carb and diesal applications I dont know if they would give you enough pressure.I think my book has a little different pressures than what your book said.
Engine off ign on 23 to 31 psi
Engine at idle 13 to 20 psi
Fuel injector resistance .5 to 1.5 ohms at 68 deg F.
Unbe

[DOCTORBILL]

Originally Posted by unbe

according to my Haynes manual
1)relieve fuel pressure
2)remove air cleaner
3)remove fuel feed line from throttle body and T in a gauge,clamp line securely and check for leaks
A couple of other things that come to mind are,have you changed\checked your fuel filter?Did you resolve the intermittent low voltage to the MAP sensor issue? I wonder if disconecting your MAP sensor puts it into open loop wich maskes the original problem.An inline would have to be wired in a manner that it would shutdown in a crash,and the ones I've seen were used in carb and diesal applications I dont know if they would give you enough pressure.I think my book has a little different pressures than what your book said.
Engine off ign on 23 to 31 psi
Engine at idle 13 to 20 psi
Fuel injector resistance .5 to 1.5 ohms at 68 deg F.
Unbe

I had the fuel filter changed about a month ago.

I haven't checked the voltages on the MAP Sensor yet as I have just
come down with a rotten cold and it is raining here now. I feel like
a big ball of crap with a dribbling faucett open above my mouth.

Anyway - the ECM Light reports 'no failures' (12).....

Should I just go out and buy a simple pressure gauge for $5 like those
used on swimming pool pumps? They go to maybe 45 psi.

I have a bunch of tests to do on this car. If the weather permits,
I'll check all the voltages on the MAP, the pump power line under the
seat, and then mess with the idle screw since it won't idle. Maybe
it is so far out of adjustment now that a new MAP is in place.

I have to at least get the damned thing to run at idle before I can
adjust or check anything!

I plan to visit the 'Pull-n-Save' to see if the '93 Metro there still has
it's ECM.... I'd like to obtain another one in case this one goes south.

Right now I'm driving my '91 Jeep Cherokee that sucks gas at 20 mpg.

DoctorBill

[unbe]

I'm not the best source of where to get them the shops I worked at were mainly in the Air Force so the gauges were in the tool crib I never had to buy one. I would make sure it says some thing in the description about being able to handle gas.I put in "fuel pressure gauge" in my search engine and it looks like gauges are around 10-12$ and kits with gauge,hose and fittings are about 45-50$.Or better yet I'm sure you got a friend that has one or a friend thats got a friend that has one. Thats how I operate of course that works both ways, I lent out my weedwacker two years ago and I still can't remember who has it.Good luck I hope your weather inproves its warmed up enough that the ice is getting almost too thin to fish on in W.I.

[Crvett69]

i had one that did the same thing, pressure was fine at idle but it had no volume, after tearing my hair out and changing every sensor on the car i pulled the return line off and stuck it in a jar. started the car and i had no return fuel coming out. replaced the pump and it fixed the problem. if you want a gauge and fittings you can go to schucks and get the fuel pressure test setup, they sell for about $30 for the setup

[DOCTORBILL]

Originally Posted by Crvett69

i had one that did the same thing, pressure was fine at idle but it had no volume, after tearing my hair out and changing every sensor on the car i pulled the return line off and stuck it in a jar. started the car and i had no return fuel coming out. replaced the pump and it fixed the problem. if you want a gauge and fittings you can go to schucks and get the fuel pressure test setup, they sell for about $30 for the setup

This damned '93 car has me so confused, I don't know what to do!

I recently replaced the MAP Sensor (CEL showed 31) with a '94 MAP.
Had to adapt the socket - different shape. CEL went out.

Won't run - dies out. Won't idle.

Unplug the MAP Sensor and the bastard runs! Idles FINE! Doesn't
run well and mpg's down from 47 to 24.

Hook the MAP back up - dies.

So - I suppose that being the case - THIS CANNOT BE the fuel pump!
Is my logic correct about the Fuel Pump?

Someone said the TP sensor and the MAP share the same circuit.

Where the heck is the TP Sensor located on a '93 TBI 3 cyl Metro
engine?
And how does it work?

AND - The return Line! Wouldn't that then be a valve in the TBI that
is bad?

Many questions above!

DoctorBill

PS - Does anyone know Blake (DieInterim)? Is he alive?