Cowboy79

Hello everyone,

my name ist Stefan, 36, from Germany and I've got a 1992 Firebird V6, 3.1l, automatic transmission.

I used the search already to find a solution to my problem, but didn't find the right one. If there is already one, please tell me and we can delete the thread, of course.
I hope I find the correct technical words...
My problem is years old.
When I turn the ignition key (without starting), you can NOT hear the typical sound of the fuel pump. That means there is no fuel in the engine when I turn the key further to start. When I do so, the starter will try and try to start the engine, but nothing changes for maybe six seconds. Then I can see the oil-pressure building up in the display and as soon as it reaches a normal level, the engine starts and everything is perfect.
When I turn off the engine again shortly after starting, I can hear the sound of the fuel pump.
For maybe one hour after the last running of the engine, the starting process works without problems (and it is not important if I drove for a long time or ran idle for just three seconds). I guess the fuel which is still in the tubes is what makes the difference here.
The SES-error code is 54 "Low voltage at fuel pump OR Low voltage at Fuel pump relay OR Output failure at quad driver module". It does not come up every time, but often.
Bridging the OBD(ALDL)-Pins A and G while ignition is turned on (without starting the motor) has NO reaction (I think the fuel pump should be running then).
I looked at all the fuses and they seem to be OK.

Anyone any idea?

Thanks
Stefan

bigal55

iTrader: (1)

I think you are supposed to connect a +12 volt signal to terminal G at the ALDL connector to power the fuel pump as a test. You are just grounding that terminal by jumping it to terminal A which is the ECM ground.
It sounds as if your fuel pump relay is bad. What is happening is your oil pressure switch has a second set of contacts that close when it sees above ~3 pounds of pressure. This set of contacts is in parallel with the fuel pump relay and will turn on the fuel pump when closed thus allowing the engine to run. The oil pressure switch is designed as a backup incase the fuel pump relay is faulty. Here is a diagram of the ALDL wiring. I will see if I can get a complete fuel pump wiring diagram for you. HTH!

bigal55

iTrader: (1)

Here is the complete wiring diagram for a 90 V6 fuel pump. GL!

Cowboy79

Thanks a lot!

I have now tested the relay myself by connecting the red (A) and grey (E) cable at the relais. Nothing happened. Letters are shown here: http://shop.cars-stripes.com/epages/...jectID=8233484

So, if the battery as power source and the fuel pump as load are OK and the relais also is not the problem, I guess it must be the wiring in between, right?

bigal55

iTrader: (1)

No, the red wire goes to the ALDL connector and is where you apply 12 volts to power the pump, or, you need to jump between the orange wire (12 volts fused with key on or start) and the grey wire to bypass the relay. The red wire is not connected to 12 volts normally and is used to test the fuel pump by applying 12 volts to the terminal at the ALDL connector. This should work provided you relay is not totally shot. By jumping the red wire to the grey wire, you are not supplying voltage to the pump, just bypassing the normally closed contact in the relay. HTH!

Cowboy79

You're right!
I tried the orange cable today and the fuel pump worked!

Now I have to find out if the ECM is damaged or the wiring.

Is it possible to use one of the two relays next to the fuel pump relay (I think fan and AC compressor) to test the relay(s)? They look pretty much like the fuel pump relay (and the numbers printed on them are the same, too).

Thanks,
Stefan

Cowboy79

Hi,

believe it or not: I checked the relay again and it worked: You could feel it, could hear it and measure it - but when built in, it never worked.
Then we exchanged the relays next to the fuel pump relay and then the fuel pump was accessed immediately after ignition. WE DID THIS BEFORE, but then it did not function.

Anyway, I bought a new relay and now everything is fine - wasn't it the starter, which is now dead - one start before it would have been able to start within a second again it went broke. I could cry...

Do you think, I need a new starter or can it be repaired? There is something clicking loudly when I start, but that won't make the engine run. And it does not sound too nice to your ears...

But apart from that: Thanks a lot for your help! :-)

Stefan

bigal55

iTrader: (1)

Glad to hear you got the fuel pump system figured out, but about that starter, ouch! It seems there is always something going on with these older cars, just part of owning a "classic" I guess. Make sure your battery is fully charged and all your cable connections are clean and tight. You say the starter makes a horrible sound when you try to start the engine, what kind of sound? Is it a grinding type of metal on metal sound? If there is a grinding noise, remove the dust shield from the trans/bell housing and look at the ring gear on the flexplate/flywheel to see if there is any damage. Make sure your starter mounting bolts are tight. A starter can be repaired provided you have access to the parts needed, it is nothing more than a DC motor. To do a good rebuild, you would need new brushes, new bearings (bronze bushings in the end caps) and probably a new pinion gear assembly (sometimes referred to as a Bendix). These parts all together are almost the cost of a new starter so, unless you can source the parts cheap enough and have the tools to disassemble, clean and repair the starter, I would advise you to maybe source a new starter if there is a problem with it. You may only need a new solenoid if the starter only "clicks" when you try to start the engine, but again, make sure all your cable connections are clean and tight. HTH!

Cowboy79

The sound is like a machine gun (and nearly that loud...), metal on metal.

I attached an .amr-recording in a .zip-file of it. You can open it with VLC Player.

But I think I might try a whole new starter...

Thanks again!

Edit: Congrats, that was your 500th post! :-)

Knightan

Hello! Have a firebird 1992 v8 tbi with same problem.

I notice that the fuel relay don't click and it take about 8 sec to start the car. When the oil pressure rise the car start....

Annyhow. I notice something new today. My ignition key! Some times the fuel relay click and some time dosen't When i turn the key. I think the ignition is bad

topduarte

iTrader: (8)

Ill send u a wiring diagram from my 92 camaro factory service manual later tonight. It should be the same.

Knightan

Thank you! I Will try to oil the ignition switch and the tilt stegring wheel path

vorteciroc

Once you have an Ignition-Switch Schematic; carefully examine the Heavy-Gauge Wires that run down the Steering-Column.
Those Wires/ Circuits, and the Electrical-Connectors that you see (with the Linkage) comprise the Ignition-Switch.
Note: there is also Linkage for the Head-Lamp High-Beam/ Low-Beam Switch (NOT what you are looking for).

The Image below shows a similar Ignition-Switch/ Linkage from a newer (1995) Camaro:


Please do not put Oil anywhere near the Ignition-Switch (or anything electrical for that matter).


If you were referring to the Lock-Cylinder for the Ignition-Switch... Dry-Graphitic/ Graphite-Powder Lock-Cylinder Lubricant works very nicely (and will not gunk-up, like Oil does).

If you were referring to the Ignition-Switch Linkage/ Rod that is operated by the Lock-Cylinder... WD40 works well, without issues.


Good luck, and have fun!

Knightan

This is very intresting. I also have some problem with my popup headlights...

I will use wd40

Time to digg in

topduarte

iTrader: (8)

Let me know uf you need anything else

Knightan

I solved one of my problems. The fuel relay was broken. I made the mistake to replace wrong relay .... LoL

The old relay click when power but no contact..

1. Grey small cable =fuel relay
2. red and black large cable = fan relay

I Will check the ignition switch because it fail to start the relay 2 of 10 times.