L-jet trouble shooting questions Options

[echocanyons]

I have a 75 with a 1.8 & l-jet.

I recently purchased this car as a non-runner but in good overall structural condition.

I am now at the point where it cranks by the key and I get spark and fuel but the injectors are not functioning.

the checklist of things I have checked are:

1. Compression, good all the way around

2. Spark, also good all the way around

3. Fuel, good pressure, fuel pump runns when the AFM flap is moved and when the starter is engaged.

4. ignition switch replaced by me for a non-functioning one.

5. The dual relay were replace by a used unit that seems to work

6. The thing I know is wrong is, the injectors are not opening or getting a charge to open. I understand that normally the signal to power the injectors comes from the coil & they open twice per crank rotation in a non-sequential fashion.

Are they powered by the ECU as well? Where should I start looking next?

I bet if I can get the injectors to fire this puppy will start right up.

[7275914911]

I have a 75 with a 1.8 & l-jet.

I recently purchased this car as a non-runner but in good overall structural condition.

I am now at the point where it cranks by the key and I get spark and fuel but the injectors are not functioning.

the checklist of things I have checked are:

1. Compression, good all the way around

2. Spark, also good all the way around

3. Fuel, good pressure, fuel pump runns when the AFM flap is moved and when the starter is engaged.

4. ignition switch replaced by me for a non-functioning one.

5. The dual relay were replace by a used unit that seems to work

6. The thing I know is wrong is, the injectors are not opening or getting a charge to open. I understand that normally the signal to power the injectors comes from the coil & they open twice per crank rotation in a non-sequential fashion.

Are they powered by the ECU as well? Where should I start looking next?

I bet if I can get the injectors to fire this puppy will start right up.

There is an injector relay pack. Could it not be plugged up or possible broken wires in the pack itself. Mine is on the passenger firewall about where the bottom of battery tray would be.

Good Luck
Ken

[sean_v8_914]

I'll second that. check relay pack center lead

[zx-niner]

If the above suggestion doesn't work, one thing that always caught me out on my '75 L-jet was a lone white wire that came directly from terminal 1 of the ECU to T-1 of the coil. The Haynes manual shows it in the current flow diagram as a black wire but for some reason it was white on my car. I don't know how many times I forgot to hook up that single wire after re-installing the engine and the engine would crank but not start.

I have no idea what the wire did or if the wiring was modified prior to my getting the car but it was a critical part of getting the car started.

[Cap'n Krusty]

Bingo! That's the wire that tells the ECU when to fire the injectors. Goes to the point side of the coil, and the engine will not run without it. The Cap'n

[echocanyons]

thanks for the tips

The white wire is in place on the coil.

I switched out the resistor pack with another and still no go (not sure if they are both no good though), I will try & test it tonight.

[r_towle]

Get two baby food jars..the little glass ones...or an equivelent.

Remove the AFM from the intake boot
Remove the fuel injectors from the intake manifold, passenger side.
Place both injectors in the baby food jars.
Using a pencil, hold the flapper door open on the AFM.
Turn key on...you should hear the fuel pump running.
Remove high tension coil wire from coil to distributor
have someone turn over car like you are trying to start it.
Watch the injectors to see if they are firing and spraying correctly.

Rich

[echocanyons]

finished the spray test, all looks good.

It must have been a loose connection at the resistor pack because the seem to spray now.

It ran for the first time under my watch (IMG:style_emoticons/default/aktion035.gif)

progress feels good (IMG:style_emoticons/default/biggrin.gif)

I sounds like it has a nasty exhaust leak though.

[Drums66]

Corosion is not our friend with these cars.......
sometimes just simply disconnecting and re-connecting
the diffferent connection's through-out the engine compartment
and so forth does the trick! especially after long period's of
sitting outside.........glad to hear it worked out for you! (IMG:style_emoticons/default/beer.gif)