'88 325 Fuel delivery problem,..

On 27 Dec 2007 08:55:24 -0500, kludge.RemoveThis@panix.com (Scott Dorsey) wrote:

>cosmo <puuuurrrh,..> wrote:
>>Ok, the stalling problem is now over. The car just cranks and won't
>>start, so at least it's not an intermittent fault and it's in the
>>driveway.
>
>Excellent!
>
>>I have spark. Fuse 11 is good. I have battery voltage at term 30 and
>>86 on the main relay. I can light a test lamp at the main relay r/w
>>wire by turning the key on with the air idle stabilizer valve harness
>>disconnected. I have voltage at term 30 of the fuel pump relay. If I
>>pull the FP relay and jump term 30 to 87 I still can't start the car.
>>This should hot wire the fuel pump, if I'm following things correctly
>>and jumped the right wires.
>
>Are you using a high-Z voltmeter, or are you using a test light? Use
>a test light. Sometimes a broken connection will have just enough leakage
>to trigger a modern digital meter but not enough to actually drive a
>motor.
>
>An old analogue meter will usually be fine.

$35 craftsman digital meter. The manual said use an LED or digital
meter.

>
>>With the relay plugged in I test for voltage between term 85 and 86
>>while turning the key on. I get no voltage- which is a fault condition
>>but I don't see where the fault is. That's as far as I got today.
>
>This is going to the relay winding? You don't care about that because
>yu KNOW the problem is after the relay, since hotwiring the relay doesn't
>solve the problem.
>

Well I thought it was the "secondary" side of the relay. The circuit
the relay controls- which drives the fuel pump. It sounds like the
book is saying if you have no voltage here the FP relays bad or not
getting battery voltage from the main relay.

>>What's the next logical thing to try? If I have to test at the
>>Motronic brain thing behind the glove box I'm disconnecting the main
>>harness and probing the connectors not the computer, right? You're
>>really testing the wiring and sensors, not the chip, right?
>
>I'd stick a test light right on the fuel pump and make SURE it doesn't
>come on. I bet it does come on, and consequently the problem isn't
>electrical. The output of the computer drives the winding of the relay
>that turns on the voltage to the pump. You know that bypassing the relay
>doesn't do any good, so that probably has nothing to do with it.
>
>Unless of course the Motronic ECM isn't getting power either because the
>run relay is bad....
>
>Make yourself a test lamp by soldering leads to an indicator bulb.
>--scott

thanks again.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

"Scott Dorsey" <kludge RemoveThis @panix.com> wrote in message
news:fl0asc$lrq$1@panix2.panix.com...
cosmo <puuuurrrh,..> wrote:
>Ok, the stalling problem is now over. The car just cranks and won't
>start, so at least it's not an intermittent fault and it's in the
>driveway.

Excellent!

>I have spark. Fuse 11 is good. I have battery voltage at term 30 and
>86 on the main relay. I can light a test lamp at the main relay r/w
>wire by turning the key on with the air idle stabilizer valve harness
>disconnected. I have voltage at term 30 of the fuel pump relay. If I
>pull the FP relay and jump term 30 to 87 I still can't start the car.
>This should hot wire the fuel pump, if I'm following things correctly
>and jumped the right wires.

Are you using a high-Z voltmeter, or are you using a test light? Use
a test light. Sometimes a broken connection will have just enough leakage
to trigger a modern digital meter but not enough to actually drive a
motor.

An old analogue meter will usually be fine.

>With the relay plugged in I test for voltage between term 85 and 86
>while turning the key on. I get no voltage- which is a fault condition
>but I don't see where the fault is. That's as far as I got today.

This is going to the relay winding? You don't care about that because
yu KNOW the problem is after the relay, since hotwiring the relay doesn't
solve the problem.

>What's the next logical thing to try? If I have to test at the
>Motronic brain thing behind the glove box I'm disconnecting the main
>harness and probing the connectors not the computer, right? You're
>really testing the wiring and sensors, not the chip, right?

I'd stick a test light right on the fuel pump and make SURE it doesn't
come on. I bet it does come on, and consequently the problem isn't
electrical. The output of the computer drives the winding of the relay
that turns on the voltage to the pump. You know that bypassing the relay
doesn't do any good, so that probably has nothing to do with it.

Unless of course the Motronic ECM isn't getting power either because the
run relay is bad....

Make yourself a test lamp by soldering leads to an indicator bulb.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis.
-----

Is there any chance of trying another ECU for the car, just to see if it
starts?
It would almost immediately rule it out as a source of the problem and would
take 5 minutes.
I was thinking timing signal issue, too.
Where are you located, country-wise?

Bill in Omaha
'86 535i
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

"Bill" <wechorba.RemoveThis@yahoo.com> wrote:

> Is there any chance of trying another ECU for the car, just to see if it
> starts?
> It would almost immediately rule it out as a source of the problem and
> would
> take 5 minutes.

The OP could do that, but at this point it is almost 100% sure to be the
fuel pump.
In fact, the symptoms from the start have pointed to a fuel pump in my
experience.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

On Thu, 27 Dec 2007 13:41:12 -0500, "Bob Smitter"
<bsmitter.DeleteThis@nospamcox.net> wrote:

>"Bill" <wechorba.DeleteThis@yahoo.com> wrote:
>
>> Is there any chance of trying another ECU for the car, just to see if it
>> starts?
>> It would almost immediately rule it out as a source of the problem and
>> would
>> take 5 minutes.
>
>The OP could do that, but at this point it is almost 100% sure to be the
>fuel pump.
>In fact, the symptoms from the start have pointed to a fuel pump in my
>experience.

A spare ECU? Are you joking? I can't even find 6 godam spark plugs for
this thing? I live the pacific nw, usa. I will try and find the fuel
pump, which was replace 3 months ago by the previous owner and check
that ooot. tanks again.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

Bob Smitter <bsmitter.DeleteThis@nospamcox.net> wrote:
>"Bill" <wechorba.DeleteThis@yahoo.com> wrote:
>
>> Is there any chance of trying another ECU for the car, just to see if it
>> starts?
>> It would almost immediately rule it out as a source of the problem and
>> would
>> take 5 minutes.
>
>The OP could do that, but at this point it is almost 100% sure to be the
>fuel pump.
>In fact, the symptoms from the start have pointed to a fuel pump in my
>experience.

Precisely. A lamp across the fuel pump wires will tell you for sure.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

"cosmo" <kibbles DeleteThis @bits.com> wrote in message
news:re18n3l7h2jee9g3eplrec947jmc46tohm@4ax.com...
On Thu, 27 Dec 2007 13:41:12 -0500, "Bob Smitter"
<bsmitter DeleteThis @nospamcox.net> wrote:

>"Bill" <wechorba DeleteThis @yahoo.com> wrote:
>
>> Is there any chance of trying another ECU for the car, just to see if it
>> starts?
>> It would almost immediately rule it out as a source of the problem and
>> would
>> take 5 minutes.
>
>The OP could do that, but at this point it is almost 100% sure to be the
>fuel pump.
>In fact, the symptoms from the start have pointed to a fuel pump in my
>experience.

A spare ECU? Are you joking? I can't even find 6 godam spark plugs for
this thing? I live the pacific nw, usa. I will try and find the fuel
pump, which was replace 3 months ago by the previous owner and check
that ooot. tanks again.
-----

I posted earlier that I may have a spare ECU and I may even have a line on
the fuel pump you need.
At this point, if it isn't the fuel pump, and my ECU matches yours, you pay
shipping and I'll loan it for free.
If that fixes the problem, I'll cut you the second best deal you ever
thought on it.

Bill in Omaha
'86 535i
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

Contact me at wechorba RemoveThis @yahoo.com. I've got some specific info for you. Lots
of colloected stuff you can use, all on CD.

Bill in Omaha


"cosmo" <kibbles RemoveThis @bits.com> wrote in message
news:cj96n3dqb21pm6a7aort8ji4jeu7jto0c7@4ax.com...
Ok, the stalling problem is now over. The car just cranks and won't
start, so at least it's not an intermittent fault and it's in the
driveway.
I have spark. Fuse 11 is good. I have battery voltage at term 30 and
86 on the main relay. I can light a test lamp at the main relay r/w
wire by turning the key on with the air idle stabilizer valve harness
disconnected. I have voltage at term 30 of the fuel pump relay. If I
pull the FP relay and jump term 30 to 87 I still can't start the car.
This should hot wire the fuel pump, if I'm following things correctly
and jumped the right wires.
With the relay plugged in I test for voltage between term 85 and 86
while turning the key on. I get no voltage- which is a fault condition
but I don't see where the fault is. That's as far as I got today.
What's the next logical thing to try? If I have to test at the
Motronic brain thing behind the glove box I'm disconnecting the main
harness and probing the connectors not the computer, right? You're
really testing the wiring and sensors, not the chip, right?
For those of you joining our program already in progress, this is a
continuation of the "325 dies under way" thread.
1988 325 auto 2.7L, red.
Thanks as always.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

Do the fuel pump delivery test that's in the Bentley manual.


"cosmo" <kibbles DeleteThis @bits.com> wrote in message
news:cj96n3dqb21pm6a7aort8ji4jeu7jto0c7@4ax.com...
> Ok, the stalling problem is now over. The car just cranks and won't
> start, so at least it's not an intermittent fault and it's in the
> driveway.
> I have spark. Fuse 11 is good. I have battery voltage at term 30 and
> 86 on the main relay. I can light a test lamp at the main relay r/w
> wire by turning the key on with the air idle stabilizer valve harness
> disconnected. I have voltage at term 30 of the fuel pump relay. If I
> pull the FP relay and jump term 30 to 87 I still can't start the car.
> This should hot wire the fuel pump, if I'm following things correctly
> and jumped the right wires.
> With the relay plugged in I test for voltage between term 85 and 86
> while turning the key on. I get no voltage- which is a fault condition
> but I don't see where the fault is. That's as far as I got today.
> What's the next logical thing to try? If I have to test at the
> Motronic brain thing behind the glove box I'm disconnecting the main
> harness and probing the connectors not the computer, right? You're
> really testing the wiring and sensors, not the chip, right?
> For those of you joining our program already in progress, this is a
> continuation of the "325 dies under way" thread.
> 1988 325 auto 2.7L, red.
> Thanks as always.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

On 27 Dec 2007 14:03:34 -0500, kludge RemoveThis @panix.com (Scott Dorsey) wrote:

>Bob Smitter <bsmitter RemoveThis @nospamcox.net> wrote:
>>"Bill" <wechorba RemoveThis @yahoo.com> wrote:
>>
>>> Is there any chance of trying another ECU for the car, just to see if it
>>> starts?
>>> It would almost immediately rule it out as a source of the problem and
>>> would
>>> take 5 minutes.
>>
>>The OP could do that, but at this point it is almost 100% sure to be the
>>fuel pump.
>>In fact, the symptoms from the start have pointed to a fuel pump in my
>>experience.
>
>Precisely. A lamp across the fuel pump wires will tell you for sure.
>--scott

It seems the fuel pump is working after all. I pulled the cover and
stuck the hose in a pop bottle. When I crank the engine fuel comes out
a plenty. Still no start. I'm kind of stuck here at this point.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

>
> It seems the fuel pump is working after all. I pulled the cover and
> stuck the hose in a pop bottle. When I crank the engine fuel comes out
> a plenty. Still no start. I'm kind of stuck here at this point.

I'm not sure what you mean by 'the cover'.
This sounds like you are checking the transfer pump ( the one that's in the
tank).
You need to check the main pump. (The one in front of the left rear tire)
Disconnect the rubber line from the cold start valve or the firewall end of
the fuel rail.
The Bentley manual also recommends checking the fuel pressure at the fuel
rail.
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

>On 27 Dec 2007 14:03:34 -0500, kludge.DeleteThis@panix.com (Scott Dorsey) wrote:
>
>It seems the fuel pump is working after all. I pulled the cover and
>stuck the hose in a pop bottle. When I crank the engine fuel comes out
>a plenty. Still no start. I'm kind of stuck here at this point.

Good news! Okay, now measure fuel pressure at the rail. If fuel is
coming out of the pump but not appearing at the rail, you have a limited
number of things that can be wrong. These include the regulator and
the filter.

Remember, to run, cars need FAST: Fuel, Air, Spark, and Timing. You have
verified you have spark, now you need to make sure you have air coming
in, exhaust going out, fuel in the cylinder, and that all this stuff is
happening at the same time.

If you DO have pressure at the rail, pull an injector and see that the
injectors are opening and spraying a nice even burst. If there is pressure
at the rail, but the injectors aren't opening, it's time to look at the
ECM.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

On Sat, 29 Dec 2007 09:32:29 GMT, "Jack" <jack_noble RemoveThis @verizon.net>
wrote:

>
>>
>> It seems the fuel pump is working after all. I pulled the cover and
>> stuck the hose in a pop bottle. When I crank the engine fuel comes out
>> a plenty. Still no start. I'm kind of stuck here at this point.
>
>I'm not sure what you mean by 'the cover'.
>This sounds like you are checking the transfer pump ( the one that's in the
>tank).

That's what has me confused. According to Bentley the 1988 325 has no
separate transfer pump; just a main pump inside the tank, which is
accessed by removing the back seat. However, on my '88 the item under
the oblong cover on the passenger side looks exactly like the picture
of a transfer pump for '84 - '87 models- one fuel outlet, a white two
wire connector (fuel gauge sender) and a black 3 wire connector to
power the pump. Go figure. This looks to be brand new and may be what
was replaced in August- not the main pump as stated in the shop bill.
I will have to get under this thing somehow and try to find the main
pump. There's a round cover on the drivers side which is, I guess, the
tank sender for the second half of the gas tank- just one white
connector with two wires. The plot thickens.

>You need to check the main pump. (The one in front of the left rear tire)
>Disconnect the rubber line from the cold start valve or the firewall end of
>the fuel rail.
>The Bentley manual also recommends checking the fuel pressure at the fuel
>rail.
>
 >> Stay informed about: '88 325 Fuel delivery problem,.. 

"cosmo" <dfvxbgd.DeleteThis@dfbgx.com> wrote in message
news:79men3hm495q2kdr9q7n15ibgpgcht4ksu@4ax.com...
On Sat, 29 Dec 2007 09:32:29 GMT, "Jack" <jack_noble.DeleteThis@verizon.net>
wrote:

>
>>
>> It seems the fuel pump is working after all. I pulled the cover and
>> stuck the hose in a pop bottle. When I crank the engine fuel comes out
>> a plenty. Still no start. I'm kind of stuck here at this point.
>
>I'm not sure what you mean by 'the cover'.
>This sounds like you are checking the transfer pump ( the one that's in the
>tank).

That's what has me confused. According to Bentley the 1988 325 has no
separate transfer pump; just a main pump inside the tank, which is
accessed by removing the back seat. However, on my '88 the item under
the oblong cover on the passenger side looks exactly like the picture
of a transfer pump for '84 - '87 models- one fuel outlet, a white two
wire connector (fuel gauge sender) and a black 3 wire connector to
power the pump. Go figure. This looks to be brand new and may be what
was replaced in August- not the main pump as stated in the shop bill.
I will have to get under this thing somehow and try to find the main
pump. There's a round cover on the drivers side which is, I guess, the
tank sender for the second half of the gas tank- just one white
connector with two wires. The plot thickens.

>You need to check the main pump. (The one in front of the left rear tire)
>Disconnect the rubber line from the cold start valve or the firewall end of
>the fuel rail.
>The Bentley manual also recommends checking the fuel pressure at the fuel
>rail.
>-----

Crossover year!
My '88 325is had a single pump in the tank, passenger side. The drivers side
tank opening is not for a pump.
The fuel filter is under the car, just forward of the rear wheel on the
drivers side. It may be under a plastic cover.
Prior to 1987 switch to 1988 "model year", there were 2 fuel pumps (like my
'86 535i has). That internal fuel pump
for the Vega is more than enough to get the required fuel pressure at the
fuel rail. Like I said, it can pressurise the system even without the main
external pump on my car. You may check the wiring and connector at the top
of the fuel tank.
Jumper the fuel pump (at the relay, per the Bentley) to run while you check
the connectors at the tank lid.

Bill in Omaha
'86 535i
 >> Stay informed about: '88 325 Fuel delivery problem,..