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Discussion Starter · #1 ·
hey guys im new to the whole import car scene but i am a very good mechanic. my freind has just bought an alpha romeo which doesent run he was told by the guy he bought it from it needed a new computer. we have replaced the computer and the key as well everything works but the engine will not run on its own. ie need gas or either sprayed into intake. has new fuel pump filter and pressure regulator. i have checked and we have fuel all the way up to the rail. i was thinking that there might be some kinda cut off switch or some kinda saftey thing stopping the injectors from working anyone have any ideas?
 

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Welcome to the Alfa BB

1) it's an Alfa Romeo
2) what color is it? How can we help diagnosis things when we don't know all the details!?! And other minor details like model year, etc.

Click on the link in my signature to a page of info about L-jetronic Diagnosis. L-jet is a system - all the bits have to work for it to work at all.
 

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Discussion Starter · #3 ·
Welcome to the Alfa BB

1) it's an Alfa Romeo
2) what color is it? How can we help diagnosis things when we don't know all the details!?! And other minor details like model year, etc.

Click on the link in my signature to a page of info about L-jetronic Diagnosis. L-jet is a system - all the bits have to work for it to work at all.
its a 2002
 

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Discussion Starter · #6 ·
im sorry to have so little info to start with as its not my car and no it looks nothing like that at all. its an 1985 alpha romeo spider
 

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Discussion Starter · #7 ·
As i said before the car will run perfectly as long as fuel is supplied via the air intake. also it will start without either and run 2-3 seconds and die out
 

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OK, so it is a 1985 AlFa Romeo Spider. Those I know a little about. Please start by noting it is an AlFa. Some people get quite uppity when you call it an alpha...

Start by going through the Spider L-jetronic Diagnosis page. Check everything - it all has to work for it to work at all. The fact it'll run for a bit on ether (don't over do that) means the ignition system is likely OK. That it'll start & run for a few seconds likely means the fuel pumps can work - but that they are not working properly after the engine starts. The fuel pumps (there are two - one in the tank and the main pump under the car) run only under two conditions: Condition 1) the engine is running - the drive relay gets a signal via a sense wire at the coil to 'know' the engine is running. It then powers on the fuel pumps. So, no spark = no fuel. Condition B) the key is turned to the 'start' position. This sends power to the fuel pumps via a bypass circuit (it bypasses the drive relay) to ensure the engine gets fuel during cranking. Once the engine starts, the drive relay is supposed to take over. Thus, your description of what the car is doing/not doing would lead me to a faulty drive relay or possibly a faulty main relay (or both...). Info about the location of these relays is in the L-jet Diagnosis page.

Note that the drive relay is not a common device - unfortunately it is not inexpensive. There are replacements that fit but be aware there are reports that they do not always operate correctly. What I've read is that they may not disable the fuel pumps when the engine stalls (as might happen in an accident). This is a safety issue. For testing purposes only you can jump around the drive relay. If the engine then starts & runs properly that proves the drive relay is the culprit. See: Fuel Pump Relay Test? (especially replies # 31 & 33)
 

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yep,
remove the drive (fuel) relay - the larger of the two relays near the computor - and jump the socket between pins #30 & #87........pumps will/should run...now see if it starts and runs.
If it does, the relay is bad.

Very difficult to get the correct original Bosch (0280230001) relay,
but the KAE 3.304.500 will do the job, if not exactly as originally intended (sometimes with the KAE, the pumps will run continuously....not as Alfa designed them to)
 

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would you like a wiring diagram for a 1985 to help you troubleshoot? If so, PM me with an email address and I will send it to you.
I agree with Eric and Dom on their suggestions.
Where are you located?
 

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Discussion Starter · #11 ·
thanks for all the info guys its been a great help. im in abbeville sc usa. ok we just noticed that there is a relay missing from the pannel and yes i would love a wiring diagram to help as far as the pm i dont know how to do that on here sorry this is my 2nd day here. also i didnt know that there was 2 fuel pumps. the one under the car is the one which was replaced. and it only runs a split second when the switch is turned on. thanks so very much im going to try the jumper and will let you know the results shortly. once again thanks so much.
 

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The 2 fuel pumps both run from the same circuit which is the fuel pump relay located(Large black one) by the Jetronic computer. Both should stay running with the key in the run position.
If you give me an email address, I can send you the diagram. I will send you a PM. Click on your icon in the upper right corner of your screen to see conversations and respond.
 

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Both should stay running with the key in the run position.
No! Not if the correct Bosch drive relay is in place. As noted previously, there are other relay brands (KAE is one) that will fit but they are known to allow the pumps to run KOEO (Key On Engine Off). This is a safety issue - in the event of a crash and the engine stalls the proper drive relay will cut power to the fuel pumps. Prior to the 1985? model year Alfas with electric fuel pumps had an inertia shut off switch. In the event of a crash the inertia switch cut power to the fuel pumps. Eventually Alfa must have decided the proper operation of the drive relay made the inertia switch redundant and it was eliminated.
 

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Discussion Starter · #14 ·
ok i noticed that i am missing a relay in the fuse box but i know that the main pump comes on (at least for a second) when the switch it turned on. so doesnt that mean that the relay is good since the main pump comes on or is there more than one relay? does it have a relay for each pump?
 

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Discussion Starter · #17 ·
now that sir was very helpful i have been checking the wrong relays this whole time, i will get back to you after i check the correct ones
 

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Discussion Starter · #18 ·
ok heres an update checked the right relays i could hear the pumps-pump come on still no change tho, it fires off and dies directly aftter. also i remember reading something about a box under the hood that can cut the fuel off by the latch? is that right?
 

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Good news both pumps run. The earlier advice of going through the Ljet tuning/troubleshooting guide from the front on down is your best course of action at this point.
 
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