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Discussion Starter #1
1989 Quadrifoglio Spider will only run smoothly (not driveable) in limp mode with the AFM NOT inserted in the rubber intake hose that runs between AFM and the intake manifold.
Parts tested or replaced?

Sensors & solenoids tested or replaced.
In tank fuel pump and sock replaced
All fuel hoses tank to engine replaced
Fuel filter replaced
In line fuel pump replaced
Furl injectors replaced
All 4 rubber injector hoses replaced
AFM replaced

any ideas as to why this car STILL is not driveable?
1680650
 

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what part?
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check the dizzy and cap and rotor.. did the dizzy come loose and rotate
 

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'84 Spider Veloce
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AFM tests good in another Spider? All electrical connectors seated? Air leak, somewhere? See Eric's L-Jet guide. Good luck!

David OD
Laguna CA
 

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fuel pressure?
1. Fuel pressure regulator (FPR): remove the small vacuum hose (#2) on top and look/smell for signs of raw fuel in that hose.....any fuel in there, it is bad....replace it (use only Bosch)
2. Clamp off the return line exiting below the FPR, reconnect AFM and try to start.

Ideally test your fuel pressure with a proper gauge as per the manual.
1617219808886.png
 

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:(

Pete
 

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You say with the AFM removed. Does it do the same with the AFM installed but not connected to the harness?
I would definitely find another S3 near by and see how your ECUs work in his/her car.
As I recall, you are a long way from me in Georgia but if you pay shipping, I will be happy to try them in one of the S3s here.
 

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In 10 years time this site will be littered with threads like this as the current new cars start to have electronic issues ... and some say modern cars are better ... are they, really? Their life time is limited by all this stuff
Pete
 
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Our cars don't have a "limp mode". In other words there is a fault somewhere. The Bosch EFI is quite reliable but it is getting old. Even 'back-in-the-day' there was no easy test for the computers. It was (and still is) test all the parts/sensors/etc and if no faults are found the final step is 'replace computer'.

I suggest going through all the steps in the L-jetronic Diagnostic Guide (link is in my signature - you may need to click the down arrow to see the whole signature). L-jet is a system - all the bits have to work for it to work properly.
 

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'84 Spider Veloce
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IMHO, the Achilles Heel of L-Jet is that there's no diagnostic port. Furthermore, I suppose all these components can take only so many heat cycles, and then what?

Maybe the guy in Israel who used to sell Romabloc clamps will start making Bosch EFI sensors, LOL. Or 'Shakey' Kevin could 3-D print them?

I suppose my '84 will outlive me, and everything will be electrified for my grandkids . . . . .

David OD
Laguna CA
 

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Diagnostic ports and programs aren't all they are made out to be. Better than nothing, but often don't report any faults ... according to my father who used to be a service manager for a very large dealership for Porsche, Audi, etc.

Pete
 

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Discussion Starter #12
I am going to be able to test the ECM & what it’s getting and giving to the engine soon. I have been loaned an “Alfa”/Bosch” tester that plugs in between the wiring harness plug and the ECM.. 🤞🤞🤞
 

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Please report on that unit in use (remember we like pictures...). My understanding is that the Bosch tester (I've only read about them and seen photos) plugs in to allow one to test all the inputs to the ECU. In other words it doesn't actually test the ECU per se.

1680731
 

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Please report on that unit in use (remember we like pictures...). My understanding is that the Bosch tester (I've only read about them and seen photos) plugs in to allow one to test all the inputs to the ECU. In other words it doesn't actually test the ECU per se.

View attachment 1680731
Eric, you are pretty much correct. It tests the inputs. Some like my Auto Force can simulate a few things but it is still not a complete diagnostic test.

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Discussion Starter #15
Please report on that unit in use (remember we like pictures...). My understanding is that the Bosch tester (I've only read about them and seen photos) plugs in to allow one to test all the inputs to the ECU. In other words it doesn't actually test the ECU per se.

View attachment 1680731
Could be... I’m just going to test what I can test. I have come to a dead end as far as what the problem is with the engine running only in “limp mode”. I’d throw MORE money at it...but there’s no place to throw it at this point. I’ve done ALL that I can do at this point. Great car, no rust issues, OEM, non-modified, low mileage. It just won’t run correctly....***!
 
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