Car Starts, Runs For 2-3 Seconds...Dies!

[fetta78]

1986 Spider. Starts right up, runs for two or three seconds then dies.
I've replaced the in-tank pump, main pump, both relays near computer as well as the computer itself with known good ones off a running car. All grounds checked, at least a half tank of gas.............
I put a power test light on the in-tank pump connection, it lights up for a flash when the key is on then nice and bright untill the car dies when the light goes out. Same with the main pump, running like a champ till car dies.

Any ideas?

[ghnl]

Check for air leaks in the intake system. Loose or cracked hoses. The 'accordian' section of the plastic intake duct is known to develop cracks.

Is the harness connected to the air flow meter (on top of the air filter)?

[fetta78]

No air leaks, all intake tubes like new and checked, main harness on AFM checked, even tried un-plugging the aux air valve just to see if that would help any......no change!

[ghnl]

Have you checked the flywheel sensors? (although I don't think it'd even run for a few seconds if they were to fail...)

[Toptick]

You also might check the fuel lines between the pump & the engine. If you have a crimp/clog you might get the same symptoms as a bad pump--Lack of fuel pressure.

[jmshyla]

I seem to recall that the "starts then stalls" syndrome can be caused by a stuck AAV.

http://www.hiperformancestore.com/L-jetronic.htm

[fetta78]

Okay.....took the day off work to try and get the Spider running so I can
take it to the Keeneland Concours in Lexington KY this Saturday but........

Still no change!

To re-cap, Blew fuse for fuel pump located behind passenger seat near
computer. Replaced in-tank fuel pump and fixed the terminal that was
causing the short. No more fuse blowing! Yay!
Now car will start right up and run for two or three seconds before dieing.
I have checked and rechecked fuses under the dash. I have replaced both
computers from a running car my father in law has let me use. I have
replaced the two relays behind the passenger seat. I have removed the AFM
and hoses and checked to see if the air flap was stuck and looked at the
hoses, all good. I replaced the black box thingy mounted on the intake
manifold, I checked the fuse in the red cylinder thing under the hood by the
coil. I unplugged the Air Aux Valve....
I have a fuel pressure guage on the way just to rule out that but there is plenty
of pressure at the rail when I loosen the hose!!

This is getting crazy! The car starts right up, runs great then dies.
Something is not switching over and I can't figure out what that
something could be!

Any other ideas? Please?

[Tifosi]

AFM wiring inside it's harness plug clean, tight, and connected? (reaching)

[fetta78]

Yes sir! Even used contact cleaner when I replugged it in!
Keep tryin' folks......I gotta get it to Lexington Saturday and NOT on a trailer!!

[Greg Gordon]

It sounds to me like the main injectors are not firing. To verify this have a buddy spray starter fluid into the intake as you crank it. If it will keep running as long as starter fluid is being sprayed then the main injectors are not firing.

Assuming they don't fire the next step is to figure out if they are clogged, stuck, or not getting a signal. All three things require different solutions. If it was a V6 car I would bet it's a signal problem, however with the 4cyl only 2 need to be bad to prevent it from running so they could be stuck or clogged.

[ghnl]

I replied to the Alfa Email Digest with what could be a crazy idea. Does your Alfa have an inertia shut-off switch? If it was flukey might it allow the car to fire then kill the fuel pump? I believe the inertia switch can be bypassed by connecting its two wires together.

[socal-85]

This is an older post, and I hope you had the problem resolved by now...
I just wanted to ad my 2cents...

I've had the exact same problem with my 85 Veloce.
just about every major electrical component was replaced including the flywheel sensors... it would start right up then die...(as if the cold start valve was giving it just enough gas to fire, then sputter out.

I checked all the fuses in the red screw together holders and they were fine.
the car sat for the better part of a month while I was waiting for my F/W sensor to show up (back order) I installed it and nothing....... I noticed that if I unplugged all the fuses it would still start and die right out?

then I saw it...... there are 2 10mm bolts holding the AAV to the top of the motor. they are also the grounding points for 2 sets of wires... I was missing a bolt.... I put the 2 sets together, tightend, and I was up and running.... no problems since.

hope this might help somebody, somewhere.

[danyl]

Quote:

Originally Posted by socal-85 This is an older post, and I hope you had the problem resolved by now... I just wanted to ad my 2cents... I've had the exact same problem with my 85 Veloce. just about every major electrical component was replaced including the flywheel sensors... it would start right up then die...(as if the cold start valve was giving it just enough gas to fire, then sputter out. I checked all the fuses in the red screw together holders and they were fine. the car sat for the better part of a month while I was waiting for my F/W sensor to show up (back order) I installed it and nothing....... I noticed that if I unplugged all the fuses it would still start and die right out? then I saw it...... there are 2 10mm bolts holding the AAV to the top of the motor. they are also the grounding points for 2 sets of wires... I was missing a bolt.... I put the 2 sets together, tightend, and I was up and running.... no problems since. hope this might help somebody, somewhere.

[fetta78]

If I remember correctly it was a flywheel sensor that finally fixed the problem on that Spider!
I think..............

[rictorg]

Quote:

Originally Posted by ghnl Have you checked the flywheel sensors? (although I don't think it'd even run for a few seconds if they were to fail...)