injectors not firing

You need to decide whats at fault, the injectors or the computer.
Get a volt meter, have someone try to start the engine and see if the injectors are getting any power at all.

fivemustangs said:

Ok I have been outside working on this problem for the last 6 hours and have narrowed it down to the gauge cluster. I removed it during the process of removing my nitrous wiring and wiring my new gauges, If I wiggle the right side harness the gauges will get power and the car will start and idle good. If not or if I more it wrong the car will idle crappy and stall out. Anyone know why this is? what is on that wiring harness that has such an impact on the engine running? Its a 2002 mustang Gt convertible 5 speed with the procharger upgrade, the only thing I have done with that wiring is tapped into the ignition wire on the left side of the harness which has been there for over a year now with no problems.

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From what I'm gathering the gauge cluster is electronically taylored for the P.A.T.S. system for that car, meaning if you switch an identical gauge cluster from the same make, year, and model, the car won't start. Seems like you have short in your gauge cluster.
This is usally when W.M. Burns chimes in w/some schematics. Hes more knowledgble then I am when it comes to the systems on these cars. That needs a Batman signal to shine in the sky when help is needed, yea, hes that good.

Good use of the noid light to check for injector pulse. Did you confirm there is +12 volts to the red wire? The injectors are ground start devices. There will be +12 volts to each injector when the key is on. If not, suspect a blown fuse or cut wire.

As for the rest of your questions, really need more to go on. As mentioned, the cluster contains the PATS system. No power to the cluster, no power to PATS.

However, my vote is that you have messed up the primary power to the ignition circuit. Perhaps by wiring in additional loads. Today's ignition systems need a lot of power. Which is why they are wired on a separate high amp circuit.

In addition, the PCM needs a stable source of power as well as many of the engine's sensors. Anything that makes the supply voltage unstable is going to make it "run like crap".

What is the voltage at the battery doing when this problem happens?

Thanks trombonedemon for the kind words. I can't speed as much time online as before. Big project.

I'm a little more selective about the posts I resond to. No longer have time to play 20 questions. Focus on the posts that I can contribute to and have enough information in the opening post. The others are just going to have to go on without me.

Thanks.