1994 325 no start - lots of fun

**BlueCollarCars** · 02-24-2018, 09:31 PM

OK, purchased a one owner 325 140K Miles. Was running then wouldn't start.
Brought it home, swapped the *completely* dead battery with a good one.

Cranks at speed, but I was not getting power to the fuel pump.
Fuse is good but the relay is not providing power to the fuse slot.
When I jump the fuel pump relay, I get power to the fuel pump fuse.
No new/used/borrowed relay would put power to the fuel pump fuse. Ground terminal on relay? terminal 86 functions with the key.
That's problem number one.

Problem number two.
When I jumped the fuel pump relay, a humming noise could be heard from under the intake manifold. air injection pump? why would that turn on?
I pulled the rear seat and you can barely hear the fuel pump running. almost inaudible with the fuel pump cover on. Normal?

For problem number one,
Should I be looking at the ground signals from the computer to the relays?

For problem number two,
Any experience?

Car still does not start with fuel pump relay jumped.

Any questions/answers are appreciated.

Thanks All!

**Eric93se** · 02-25-2018, 12:52 AM

Probably the cam sensor.

**shogun** · 02-25-2018, 06:17 AM

The humming sound you hear under the intake when jumping the fuel pump relay is probably the fuel pressure regulator, which is located on the fuel rail.
Recently tested my E32 750 fuel pumps and also heard that sound, the fuel pressure pushes the fuel thru the fuel pressure regulator and pushes the diaphragm into open position, that the fuel is going thru the return line back into the tank.

**scooper** · 02-25-2018, 11:13 AM

gas in tank/no-working fuel gauge?

**E36328Coupe** · 02-25-2018, 02:08 PM

First things is first, stop messing about and do a "stomp test" to get the check engine light to flash out any fault codes.

IIRC cam sensor does not stop these starting, they batch fire instead

**BlueCollarCars** · 02-25-2018, 02:39 PM

The cam sensor is preventing the fuel pump relay from operating? I'm not sure I understand unless it has to do with the ground signal to the relay?

thank you shogun, its surprising to hear as it sounds very mechanical/electric motor drive.

Gas in tank, level sender functional.

Will pull codes on Wednesday, I am away from my shop and only have access to a test light as of now.

Still have a question from the first post,
When I jump the fuel pump relay, the pump runs but its is extremely quiet. Inaudible with the rear seat on.
Is this normal? It just barely makes a humming noise, half the volume as the sound under the intake.
Could I be looking at a bad fuel pump?

**XnWarden** · 02-25-2018, 04:47 PM

Pretty sure terminal 86 on the relay is the ignition switch for the relay. If it works with the key, and the relay is putting out power to the pump (terminal 87 is usually the output) then I'd say the wiring is fine and the pump is probably on it's way out.

Can you record the fuel pressure while manually jumping the pump?

Sent from my VS987 using Tapatalk

**Grasshopper2Ant** · 02-25-2018, 06:01 PM

I have a similar problem.
Main relay supplies power to fuel pump relay via pin 87.
If main is good, check if 12V at Pin 1 on DME connector with IGN ON.
Pin 1 supplies 12V to fuel pump relay #85.
My Pin 1 is only supplying 2.12V not 12V which is my problem and may be yours.

**Grasshopper2Ant** · 02-26-2018, 05:47 PM

Update:
The above statement is correct except:

Connector Pin#1 is supplying 2.12V is not an issue. I tested Pin#1 on another car and it gets even less voltage with IGN ON..

I suspect our issue is a grounding issue on FPR #85. Even when I ground it out and it gets fuel it will not start like your problem.

**E36328Coupe** · 02-26-2018, 05:55 PM

Originally Posted by E36328Coupe

First things is first, stop messing about and do a "stomp test" to get the check engine light to flash out any fault codes.

IIRC cam sensor does not stop these starting, they batch fire instead

Why is everyone not in favour of actual diagnostic info

**BlueCollarCars** · 02-28-2018, 08:51 PM

Originally Posted by XnWarden

Pretty sure terminal 86 on the relay is the ignition switch for the relay. If it works with the key, and the relay is putting out power to the pump (terminal 87 is usually the output) then I'd say the wiring is fine and the pump is probably on it's way out.

Can you record the fuel pressure while manually jumping the pump?

Sent from my VS987 using Tapatalk

Thank you, I don't currently have a gauge with the car, that was my first thought after I heard the pump running.

Right, it does function with the key. But does not power the fuel pump circuit with a relay in. So the relay isn't functioning due to ground issue maybe?

**Grasshopper2Ant** · 03-02-2018, 02:23 AM

I took my fuel pump relay schematic to my local auto electric guy.
Right away he said the #85 gets its ground from the DME #31.
The FPR gets it power from #1 DME.
His hunch w/o testing was the Crank Sensor as the DME is not sending. So I am going to take a chance and replace even though my ohms was 490.

**BlueCollarCars** · 03-03-2018, 03:32 AM

Originally Posted by Grasshopper2Ant

I took my fuel pump relay schematic to my local auto electric guy.
Right away he said the #85 gets its ground from the DME #31.
The FPR gets it power from #1 DME.
His hunch w/o testing was the Crank Sensor as the DME is not sending. So I am going to take a chance and replace even though my ohms was 490.

Exactly what I figured out today. No ground on 85.
I think crank and cam sensors along with a fuel pump would be appropriate in my situation.

**BlueCollarCars** · 03-03-2018, 03:37 AM

Originally Posted by E36328Coupe

Why is everyone not in favour of actual diagnostic info

No codes.

**E36328Coupe** · 03-03-2018, 12:42 PM

Originally Posted by BlueCollarCars

No codes.

As in stomp test gave no codes or diags machine gave no codes (with an ADS interface)? Still info that would be useful to say earlier.
Cam sensor won't stop it running and will generate codes (usually)

**BlueCollarCars** · 03-05-2018, 11:10 PM

Originally Posted by E36328Coupe

As in stomp test gave no codes or diags machine gave no codes (with an ADS interface)? Still info that would be useful to say earlier.
Cam sensor won't stop it running and will generate codes (usually)

Stomp test, I had 4 cars in storage and this one did not make it on the transport back, this Wednesday it will closer to a scan tool

"..Wont stop it running.." The car or the fuel pump?
Not getting a ground on the FPR terminal is why the FP isn't running, someone on the forum had indicated that the ground signal comes from the computer and it relies on the cam sensor being operational.

What would you do without the scan tool? I have a full day to work on it.

**JDStrickland** · 03-06-2018, 09:36 PM

Did you do a continuity test on the fuel pump?
The pump has a GRN/VIO and a BRN wire. The BRN is ground, the GRN/VIO is 12v.
The fuel pump does not run if there is no CPS input.

You said the car is a '94. Are you sure? If it is a '95, there is a thing called a Running Loss Solenoid and a Delay Relay. I do not know what these do, but they are tied into the fuel injector circuit. If this goes away, the Fuel Pump Relay does not fire. If the Production Date is 09/94 or later, the car is a '95. If the Production Date is before 08/94, then the car is in fact a '94.

On the ground wire to the ignition coils, there is a 240 ohm resistor, if this is open then you could have a no-ground condition to the coils. If the resistor was shorted, you would likely not know, or maybe get some noise in the radio - something like that. Loss of ground would give no spark, not no fuel. (Just covering the bases.)

**Grasshopper2Ant** · 03-07-2018, 01:24 AM

Update:

I changed my CS with a used one that had 520 ohms and the car started!

FPR #85 is grounding as it should.

Diagnostic codes may reveal CS or test for crank signal at the DME.

Easiest is to test CS removed. I tested on vehicle and it got 490 ohms which seemed OK but took off and it had dirt and grease at bottom. It may very well be my problem.

It may be DME but highly unlikely. Cam sensor and fuel pump are non factors.

**jc43089** · 03-07-2018, 08:32 AM

Just for future reference the fuel pump only runs for a couple seconds when the key is turned on until it sees the crank position sensor indicating that the engine is at a high enough RPM to indicate that it is running. So you would need to be listening under the back seat while someone turns the key to the run position. The pump should not be very loud, you won't hear it unless the seat cushion is removed and maybe even the access cover on the passenger side. The drivers side cover is just the second sending unit.

**BlueCollarCars** · 03-07-2018, 03:59 PM

Originally Posted by jc43089

Just for future reference the fuel pump only runs for a couple seconds when the key is turned on until it sees the crank position sensor indicating that the engine is at a high enough RPM to indicate that it is running. So you would need to be listening under the back seat while someone turns the key to the run position. The pump should not be very loud, you won't hear it unless the seat cushion is removed and maybe even the access cover on the passenger side. The drivers side cover is just the second sending unit.

If only this were true.

The FPR will not energize the FP circuit unless it sees the ground from the computer (which is controlled by the crank sensor). Even when turning the key to "on" with a bad sensor it will not energize the fuel pump.

Put in a new crank sensor and all is well.

I had a test light on the fuel pump fuse when turning the key, no power until I put the new crank sensor in.

- - - Updated - - -

Originally Posted by Grasshopper2Ant

Update:

I changed my CS with a used one that had 520 ohms and the car started!

FPR #85 is grounding as it should.

Diagnostic codes may reveal CS or test for crank signal at the DME.

Easiest is to test CS removed. I tested on vehicle and it got 490 ohms which seemed OK but took off and it had dirt and grease at bottom. It may very well be my problem.

It may be DME but highly unlikely. Cam sensor and fuel pump are non factors.

Same here, purchased a new unit to the tune of $65. And the car started immediately.

Thanks for touching base with me on your issue. I'm glad we were able to get things running again.

- - - Updated - - -

Originally Posted by Eric93se

Probably the cam sensor.

Final answer?

**E36328Coupe** · 03-07-2018, 05:02 PM

Originally Posted by BlueCollarCars

"..Wont stop it running.." The car or the fuel pump?

Answered in post 5

Originally Posted by E36328Coupe

IIRC cam sensor does not stop these starting, they batch fire instead

**BlueCollarCars** · 03-07-2018, 09:55 PM

Originally Posted by E36328Coupe

Answered in post 5

Originally Posted by E36328Coupe

First things is first, stop messing about and do a "stomp test" to get the check engine light to flash out any fault codes.

Originally Posted by E36328Coupe

Why is everyone not in favour of actual diagnostic info

I don't know what to say to you. I never mentioned the cam sensor until someone indicated it could be a problem.
I replaced the crank sensor after finding another ground issue thread on another forum.
you didn't help at all bud.

Originally Posted by E36328Coupe

Diagnostics aren't the be-all and end-all people think. For example wife's 325 would crank easy but not run and no fault codes a while back. The ECU would have spotted a fuel pump relay missing (low current circuit) but not the lack of fuel due to a faulty immobiliser cutting the fuel pump.

Originally Posted by E36328Coupe

Another fun one I had recently, changed oil on it, started fine, then would not start. Diags showed the EWS systems was not letting car start (no faults as working as intended)
Turns out the drivers door handle on the outside was stiff and the handle was sticking out and that was the cause...........I did not even see a ref to this in the EWS 1 manual!

In spite of the fact it may not help if I was you, and I am not, I would get INPA and ADS interface and mistreku.zip

Originally Posted by E36328Coupe

- - - Updated - - -

Wont stop the car running, no need to speculatively replace

**E36328Coupe** · 03-09-2018, 06:51 PM

Originally Posted by BlueCollarCars

I don't know what to say to you. I never mentioned the cam sensor until someone indicated it could be a problem.
I replaced the crank sensor after finding another ground issue thread on another forum.
you didn't help at all bud.

I don't know what to say to you.
Someone incorrectly indicated it could be a problem.
I indicated it wasn't.

You asked.........

Originally Posted by E36328Coupe

Originally Posted by BlueCollarCars

"..Wont stop it running.." The car or the fuel pump?

Answered in post 5

Originally Posted by E36328Coupe

IIRC cam sensor does not stop these starting, they batch fire instead

I answered whether you found it helpful or not is beyond my control.

**BlueCollarCars** · 03-13-2018, 02:05 PM

Originally Posted by E36328Coupe

I don't know what to say to you.
Someone incorrectly indicated it could be a problem.
I indicated it wasn't.

You asked.........

I answered whether you found it helpful or not is beyond my control.

Right O. Incorrectly indicated, so you brought it up another time to prove what? I wasn't asking you for anything besides clarification of your vague "it" post. "It" is pretty vague when referring to a vehicle not running.

Thanks for whatever you were trying to do.

**E36328Coupe** · 03-13-2018, 03:52 PM

It wasn't vague at all in post 5. For someone that would have looked at the red herring cam sensor it would be useful, but as I said, if you found it useful or not is beyond my control