94 Caravan - fuel pump won't run

(((Just curious - what is it that tells the fuel pump to quit pumping
before the engine starts?))) If the PCM doesnt see that the engine is
running after 3 seconds, it shuts down fuel and spark thru the ASD relay,
You know that you are getting fuel but possibly loosin spark, go to the
windshiled wiper resorvoir and under neath it is where you will locate the
fusible links, look at them and gently pull on each one to see if any are
broken/burnt.If all ok
Check b+ to PCM with a test light for voltage.If ok Check the 5 volt power
supply to the sensors for a short to ground. A short to ground on the 5 volt
power supply to sensors such as: MAP, TPS, A/C PRESSURE TRANSDUCER, EGR
POSITION, etc. will cause the vehicle to die out and may cause the PCM to be
a no response. All this of course would be easier using a scan tool to see
acuall values and be able to acuate spark and fuel systems, so taking it to
a repair facility may be the next option. Good Luck
Glenn Beasley
Chrysler Tech


> wrote in message
oups.com...
>
> Daniel J. Stern wrote:
> >
> > Remove the 60-pin connector from the SBEC and inspect the pins and
> sockets
> > for corrosion; clean the pins by pushing a pencil eraser straight
> down
> > onto each pin, and packing the sockets full of Ox-Gard or Noalox.
> >
> > Check all of the fusible links carefully; it sounds like one or more
> of
> > them may have popped. Of course if this is the case you'll have to
> find
> > the cause or the new link will pop, too.
> >
> > Check the codes and report what you find.
>
> Thanks for the tips, Daniel. I'll try these tonight and hopefully get
> it going. I wanted to donate it to my church (they in turn donate it
> to those who need cars but can't afford them), but they won't take it
> if it isn't running. And since I can't sell it (tried twice, can't
> even get an offer at $800, and it's in pretty good shape), and it's not
> doing me any good sitting in my driveway, this seemed like a good
> option.
>
> Just curious - what is it that tells the fuel pump to quit pumping
> before the engine starts? The pressure regulator only holds the
> pressure at a certain level and returns the excess back to the tank,
> right? But that's with the pump running continuously. Something tells
> it to stop when the key is on but the engine's not running.
>
> KC
>

Matt Whiting wrote:

>
> Might be faster to first use a multimeter to check for voltage on the

> supply pin to the computer. That is faster than tearing into a
bundle
> of wires.
>
>
> Matt
Good idea, Matt. There's power to the fuse block, all the lights and
gauges and everything else works fine. With the key on, there's power
to 4 pins of the SBEC connector - 3 on the left side bottom row, 1 just
above them on the middle row. So there's power to the SBEC, but it
won't flash codes and won't turn on the fuel pump or spark. Sounds to
me like it's time for a different SBEC. Opinions?

KC

Matt Whiting wrote:

>
> Might be faster to first use a multimeter to check for voltage on the

> supply pin to the computer. That is faster than tearing into a
bundle
> of wires.
>
>
> Matt
Good idea, Matt. There's power to the fuse block, all the lights and
gauges and everything else works fine. With the key on, there's power
to 4 pins of the SBEC connector - 3 on the left side bottom row, 1 just
above them on the middle row. So there's power to the SBEC, but it
won't flash codes and won't turn on the fuel pump or spark. Sounds to
me like it's time for a different SBEC. Opinions?

KC

wrote:
> Matt Whiting wrote:
>
>
>>Might be faster to first use a multimeter to check for voltage on the
>
>
>>supply pin to the computer. That is faster than tearing into a
>
> bundle
>
>>of wires.
>>
>>
>>Matt
>
> Good idea, Matt. There's power to the fuse block, all the lights and
> gauges and everything else works fine. With the key on, there's power
> to 4 pins of the SBEC connector - 3 on the left side bottom row, 1 just
> above them on the middle row. So there's power to the SBEC, but it
> won't flash codes and won't turn on the fuel pump or spark. Sounds to
> me like it's time for a different SBEC. Opinions?
>
> KC
>

First you need to check the schematic in the FSM to ensure that the 4
pins that have power are the only ones that should have power. If the
SBEC needs power at 5 pins, then it may not be the SBEC.


Matt

wrote:
> Matt Whiting wrote:
>
>
>>Might be faster to first use a multimeter to check for voltage on the
>
>
>>supply pin to the computer. That is faster than tearing into a
>
> bundle
>
>>of wires.
>>
>>
>>Matt
>
> Good idea, Matt. There's power to the fuse block, all the lights and
> gauges and everything else works fine. With the key on, there's power
> to 4 pins of the SBEC connector - 3 on the left side bottom row, 1 just
> above them on the middle row. So there's power to the SBEC, but it
> won't flash codes and won't turn on the fuel pump or spark. Sounds to
> me like it's time for a different SBEC. Opinions?
>
> KC
>

First you need to check the schematic in the FSM to ensure that the 4
pins that have power are the only ones that should have power. If the
SBEC needs power at 5 pins, then it may not be the SBEC.


Matt

On Sat, 18 Dec 2004 wrote:

> There's power to the fuse block, all the lights and gauges and
> everything else works fine. With the key on, there's power to 4 pins of
> the SBEC connector - 3 on the left side bottom row, 1 just above them on
> the middle row. So there's power to the SBEC, but it won't flash codes
> and won't turn on the fuel pump or spark. Sounds to me like it's time
> for a different SBEC. Opinions?

Looking at the 60-socket connector with the wires facing away from you,
the cavities are numbered thus:

Top row (all the way across, disregarding the central bolt post):
1 (left) through 20 (right)

Middle row (all the way across): 21 through 40

Bottom row (all the way across: 41 through 60


Cavity 3 (top row, 3rd from left): Direct battery voltage

Cavity 11 (top row, immediately to right of central bolt post)
AND
Cavity 12 (immediately to right of cavity 11) are the grounds. Check for
continuity between them and battery negative.

DS

On Sat, 18 Dec 2004 wrote:

> There's power to the fuse block, all the lights and gauges and
> everything else works fine. With the key on, there's power to 4 pins of
> the SBEC connector - 3 on the left side bottom row, 1 just above them on
> the middle row. So there's power to the SBEC, but it won't flash codes
> and won't turn on the fuel pump or spark. Sounds to me like it's time
> for a different SBEC. Opinions?

Looking at the 60-socket connector with the wires facing away from you,
the cavities are numbered thus:

Top row (all the way across, disregarding the central bolt post):
1 (left) through 20 (right)

Middle row (all the way across): 21 through 40

Bottom row (all the way across: 41 through 60


Cavity 3 (top row, 3rd from left): Direct battery voltage

Cavity 11 (top row, immediately to right of central bolt post)
AND
Cavity 12 (immediately to right of cavity 11) are the grounds. Check for
continuity between them and battery negative.

DS

Grounds are good, but no power on pin 3 with key on. Also, found a
little corrsion on 2 pins at the firewall connector, and more when I
pulled the boot back. Cleaned them up, but made no difference. Where
does the red and white wire for pin 3 go? I expected to see it coming
through the firewall connector, but didn't. Is it time to rip the
bundle apart? Are there fusible links in there?

KC

Grounds are good, but no power on pin 3 with key on. Also, found a
little corrsion on 2 pins at the firewall connector, and more when I
pulled the boot back. Cleaned them up, but made no difference. Where
does the red and white wire for pin 3 go? I expected to see it coming
through the firewall connector, but didn't. Is it time to rip the
bundle apart? Are there fusible links in there?

KC

In article
.com>,
wrote:

> Grounds are good, but no power on pin 3 with key on. Also, found a
> little corrsion on 2 pins at the firewall connector, and more when I
> pulled the boot back. Cleaned them up, but made no difference. Where
> does the red and white wire for pin 3 go?

The "engine" fuse IIRC.

> I expected to see it coming
> through the firewall connector, but didn't. Is it time to rip the
> bundle apart? Are there fusible links in there?

A 94 Caravan has but one fuse link; the one between the
alternator output stud and the battery.
Everything that -was- protected by fuse links the year before is
protected by fuses in 94.

You -did- check all the fuses didn't you?