FI help please

[clarkjw24]

Got a 93 caddy with the 4.9 Fuel injection. Cranks when it feels like it. I've replaced the fuel filter, ign. coil, ign. module and the fuel pressure is at 44psi. It doesn't seem to be firing. I pull the plug wire off and do the old screwdriver near ground test and nothing. Help me please.

 

[FWP]

Since no-one replied, I'll give some thoughts (not knowing anything about that specific system).

FP sounds about right for a rail system (just a guess)

No Spark- Does the distributor have 12V to it? If not, look at the Diagrams for where the dist. gets power from, and back track from there.

ECM inputs that have to do with spark- are they all at the correct voltage?

An intermittent is usually a connector or wiring- look at everything related closely. A DVM is your friend.

I know that's kind of general, but I hope that helps some.

 

[clarkjw24]

Thanks for the repley FWP. Yes its got 12v at the distr. and it is a rail system. I guess I need to tow it somewhere and have it put on the computer.

 

[randy88k5]

Not sure the comp will tell you the problem. I doubt its a sensor, could be though.

Id check to make sure dizzy is spinning. IIRC, the timing chains on those werent too good.

Then as FWP said, check for voltages at various points; coil, dizzy, fuses. Check for corrosion at the connectors too.


I had bad corrosion on my friends 88 Ranger. Couldnt figure out the problem until we isolated the different areas and began stripping wire. The wire was nearly totally corroded away under the insulation.

Without a schematic, I cant think of much more to check. Did you have good contact when you checked for spark.