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156 2.5 V6 Not Starting

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6K views 15 replies 8 participants last post by  bazzbazz 
#1 ·
Okay so here's the biggy:

My wagon won't start and I traced the problem down to the fuel pump as I checked the following:

All fuses in tact
Still no fuel pressure at ignition on when checking feed line to fuel rail
Relays in tact
Took apart the rear to get to the fuel pump and the supply voltage is battery voltage with ignition on and earth is good.

... so all the wiring and signals are correct, so has to be the pump right?? This is the weird part... Removed the pump, connected battery voltage and earth directly and.... IT WORKS!!! Connect it back to the car, nothing.. So I measured at different spots on the fuel pump connectors after the initial orange 4 pin clip thats at the top.. Voltage and earth is correct all the UNTIL......>>>> Theres a small 2 pin black clip that clips into the fuel pump... Disconnected the pins read battery voltage on positive and good earth BUT... When I plug it in and check them, positive reads: 0.5V and the earth reads 0.1V..

What the hell is going on???

Thanks guys...
 
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#4 ·
Hi guys, as stated before in the message. Whilst the fuel pump was still in the car, ignition on supplies 12V to the fuel pump (So fuses and relays are good!) but when disconnecting the fuel feed to the rail, there is no fuel pressure meaning the fuel pump does not switch on, however... When I removed the fuel pump and connected 12V directly to it, it switches on... There are no immobilizer lights staying on. With the 2 pin clip connected to the fuel pump it measures 0.5V but when you unplug it, it measures 12V
 
#6 ·
It sounds as though you are very close to the solution. If the volts on (the car side of) the orange connector are good with the black connector connected, but the volts on the black connector are low until it is disconnected, then you have a bad connection between or in those connectors. Since the pump runs when fed directly from a battery, via the orange connector I assume, then either the fault is intermittent and the action of making the connections to the battery at the orange connector temporarily corrects the fault, or the bad connection is in the car side of the orange connector. Try measuring from positive in to positive out of the orange connector, then negative in to out, with everything connected and switched on. If you find Volt drop (ie: more than 0.25V) you have found a problem. If not, try from orange positive to black positive etc. You just have to find where the volt drop is occurring.
 
#8 ·
You definitely have a bad connection somewhere, the 12v is there with no load, but drops when you try and put load on. It will be something somewhere that is connected enough but with any load the resistance is so high that it will drop out. It may well be that the relay is making but not enough for it to power the pump. Try swapping with a relay of the same size and see if that works.
 
#9 ·
Thanks Jiberson1! Just on a side note: I changed power steering fluid a few days ago and during this process the one pipe slipped off and sprayed steering oil all over the engine bay! I know I know... but I was in a hurry. So since that night, the car has been having trouble starting. Intermediate starting problems until I got stuck on Sunday, not starting at all. So I swapped around the relay for the fuel pump, hoping this would be the cause but no luck. I will go remove the relay for the fuel pump with its holder/bracket and see if some steering fluid is causing the problem...
 
#12 ·
"to just wire it up to positive and negative by means of the black connector."

That only means that the fault does not have to be intermittent for the logic to hold. Carry on as before!
You only need to check for bad relays etc if the 12V on the orange connector disappear.
 
#13 ·
Thank you all for the information. I am desperately trying to get around going to my folks place as the car is there. I have been driving the Giulia each day but I just have so much I need to do in our new place. I have dedicated all of Sunday to get it resolved and will try all the above measures. If I fail I'll post the details. I really hope I can get this sorted before the end of the week!
 
#14 ·
Okay guys, I'm pleased to say that the 156 is running again. Thank you all for the info. I did the following:

Plugged everything back in and ran a wire from the battery earth to the earth pin on the pump. Switched ignition on... Nothing!
Ran a wire from battery positive to the positive pin on the pump and it WORKED! So obviously positive wire to pump is at fault.
Then started at the Fuel pump relay and found no problem with positive, negative and signals but then remembered that with a faulty relay on the "INJ" slot, the car wouldnt start.
So I then checked the "INJ" relay and found that the Positve, Negative and signals are good... So knowing this could only be the relay, I took off the relay cover and watched it actuate. It clicked and moved over and for some reason I thought, let me push on the little actuating pin and it clicked louder and I heard the pump switched on. F%#@$ing RELAYS!!! My aircon also didn't work cause of the relay and the only reason the relay swop didn't work when I broke down was because I swopped it with another faulty relay without knowing it.
I picked this up as during the breakdown, the car started but died again (faulty "INJ" relay)
When I swopped the relay around with the aircon relay the car didn't even start... Pop the relays around again, car starts but dies again...

My conclusion, if you buy a second hand 156, be sure to stop at the dealership on the way home and replace all the relays!!!

Thanks very much guys.. It felt great driving to work with a heater again ha ha
 
#15 ·
Alfa 156 2.5 v6

Thank you, thank you, thank you forum users :):):)

My lads 156 wouldn't start on Xmas eve (of all times) and he called out the RAC to it.
The RAC guy said the fuel pump wasn't working so he towed it to the local garage. They couldn't/wouldn't look at it until Saturday. In the meantime I tried to source a pump on ebay and browsed this forum. I also watched how to change the pump on you tube. It looked not too difficult at all.
Can you imagine our shock when the garage came back with a £650 quote to supply and fit the pump :eek: They needed to drop out the fuel tank they said to do it.
At that it was a DIY job.
Until I read this thread we had no idea about the cutout under the seat. Off we went in my 1.9l 147 this morning to tow it home and do the work this week, maybe cost a bit for the pump but better than £650.
On arrival at the garage we took the long shot option (thank you BazzBazz) and pressed the button under the seat. Yes yes yes it worked. The face of the garage owner was a site to see. What was the £650 for we asked as we drove it off the forcourt?

Thank you all for this thread and especially BazzBazz for saving us £200, or even £650.

Happy New Year to you all.:thumbs::thumbs::thumbs:
 
#16 · (Edited)
It is my humble pleasure to make the start to your new year in life one with a smile on your face.

Take care & "Drive the bloody thing like the Italian, leather clad, sports car it is!"

(As my wife would say . . .and she's right ya know!) ;)

A VERY happy new year!

Baz

P.S. - I would have LOVED to be there & watch the look on the mechanics face . . . . .. Priceless
 
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