Alright so i have a 95 z28 with an lt1 which is rebuilt just finished and here is the problem it is only running on six cylinders and cylinders ( 6, 8)are not firing and iam out of ideas.... i dont know what else to try... i have switched fuel injectors on those two cylinders and found out they still work on different cylinders so there okay and then i put a spark checking thing on the the spark plug and the wire and watched a light flash when i started the car on the number 8 cylinder and it has spark and so then i followed the wire to the pcm and unpluged it and checked it for continuity and its fine so then i assumed it was the pcm not firing the injector so i got a new one and put it in but still had the same problem and also checked the fuses for the injectors there fine and checked them for clicking and keep in mind the motor is all rebuilt new accel coil new accel opti new taylor 10.4 wires, new bosch spark plugs.... and everything is new besides the rods and block and heads which where all redone and the heads got bigger valves put in them and thats all ive got.....please help me firgure this out ( this one time we took the water pump off after it was filled during the rebuild and the opti was on there but there is still spark so i dont know...)

 

Have you verified that you have +12V on the pink wire in the #6 and #8 injector harness connectors?

Have you tested the injector circuits by using a "noid" light?

When you "checked them for clicking", what did you find?

 

alright so is where iam at now i have found out that the pink wire coming off both injectors seems to be fine. and i dont know what a noid light is. and i need to know where the yellow/black number six wire goes and the dark blue/white eight wire goes. im thinking that the wires are broken or damaged or just not connected some where. help would appreciated

 

A noid light is a tester that plugs into the injector harness to tell you if the injector is getting a signal to operate. No sense in trying to track down a trouble that you have not confirmed is actually there. Injector signal wires go back to the PCM.
Have you read the plugs?

 

the pink wire dose have the same amount of volts as all the other wires so its fine its just that other wire on those two injector plug ins. so how do i fix the problem? and the injectors dont tick when the engine is running but when switched both injectors worked fine on different cylinders. so now its down to the two wires coming off of the injector plug ins. something is wrong with them obvisouly. so how do i fix it them?

 

You check continuity on the wires from PCM to injector with a meter. You can find wiring diagrams on my Tech Page. Sure would be nice if you had a noid light to help confirm your problem.

 

could i make my test light work the same as a noid light?

 

i checked the wires for continuity from the injector to the pcm and they are fine. anything else i can check, or a different way or something?


web site is a great help i use it all the time!

 

on your site where do you think i should check on this schematic or how even?

http://shbox.com/1/smfi_devices_injectors.jpg

 

fuses are good and checked with test light

 

on that schematic what is and where is the AIR PUMP RELAY CONTROL?

 

The AIR pump relay is in the fuse/relay box under the hood on the driver's side wheel well. The relay turns the AIR pump off. The AIR pump is bolted to the front of the engine, on the drivers side, below the coil/AC Module. The AIR pump runs for a couple minutes at startup, pushing fresh air into the exhaust manifolds, to help the cats heat up faster. It would not be causing the problems you are having.

 

so today i started the car and had two wires going of the injector itself and plugged them into the injetor plug in with a little slit on the wire not hot wire of the injector plug in. then i took that wire and ran another wire off of it and rubbed it on a ground on the car and the injector did its job and was ticking and the hedder got hot for that cyclinder! but that still leaves me with the problem of finding the problem........

 

crossed wires?

 

Its not clear at all what you did when you..

"started the car and had two wires going of the injector itself and plugged them into the injetor plug in with a little slit on the wire not hot wire of the injector plug in. then i took that wire and ran another wire off of it and rubbed it on a ground on the car"

.... I can't follow that sentence at all.

The injector is fired by the PCM supplying a ground. You are saying that you were apparently able to provide a periodic ground that just happened to fire the injector for the correct pulse width and timing to fire the cylinder correctly. Not sure how you could do that.