John, If you think the problem is a low battery, get a jump start and see if it starts. If it does, then your battery is shot.
Like the Motronic system, the L-Jet will not fire any the injectors unless 10.5 vdc is showing at the ECU. BTW, did you try tapping on the pump when trying to start the car? Sometimes this will help 'remind' the pump to start working again...but it isn't not a cure for the problem. Bruce > Date: Thu, 8 Jan 2015 12:14:25 -0800 > From: Joe Elliott <[email protected]> > Subject: [alfa] Re: Testing fuel pump in '86 Spider Quad > > The fuel pump is switched by the airflow sensor flap in *some* L-Jet cars > (e.g. GTV-6), but not, to my knowledge, in Alfa Spiders. IIRC your fuel > pump is switched by the ECU based on a (crank position Hall sensor??) > signal that the engine is turning. Your measurement of 9 V at the pump > while cranking would seem to confirm this, but begs the question--why only > 9? If that's the actual battery voltage under cranking load (as opposed to > being symptomatic of bad wiring/connections/grounds to the pump), it's > possible that the ECU has shut down to protect itself and isn't firing the > injectors. (Again I don't know the specifics of the L-Jet Alfa Spider, but > Bosch Motronic ECUs, for example, will shut down below like 10.5 V.) Try a > fresh battery. > > - -Joe > > > > > Date: Sun, 4 Jan 2015 15:38:35 -0800 > > From: "John and Deb Dohrmann" <[email protected]> > > Subject: [alfa] Testing fuel pump in '86 Spider Quad > > > > My spider was running OK until it died at an intersection and since them > > won't start, cranks fine but doesn't fire at all. Compression, fuel and > > spark, right? > > I read online that the fuel pump should come on if I turned the key to > run > > and then pushed open the air flow sensor flap. Put a remote mic on the > > pump, > > turned key on and opened air flow flapper, nothing from the pump. Ran a > > wire > > to a meter from each wire at the pump, tested against ground with key on, > > flapper open, no volts. Fuse by the brain box is good, I can hear the > main > > relay click when I turn on the key, so makes me suspect the drive relay. > > Just to be sure, I put everything back together and cranked the engine > > listening to my mic on the pump - all I could hear was the starter noise. > > Again, makes me suspect the drive relay. > > > > But just to be sure, I hooked a jumper from each side of the pump and > > measured against ground while cranking the engine, now I have 9 volts to > > the > > pump. So the article saying that opening the air flow flapper with the > key > > to on will run the pump is NOT correct. And if I have voltage to the pump > > but no pump whine, then it is the pump, not the relay. > > > > Any suggestions would be appreciated, especially how to test the fuel > pump > > function while in the car without cranking the engine. > > > > Thanks > > John Dohrmann > > 1986 Spider Quad -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
