Alright, I figured since you guys nailed the first problem I had with the 454, I'd head to you for my new issue. Notably, the distinct lack of fuel from the injectors.

Now, to rule out the things I know it isn't: Fuel pump, injectors, connectors to the injectors. I have verified that there is fuel flow to each injector, and that shorting the injectors causes them to shoot fuel out as normal. The connectors leading to them are all at 0.1 Ohms resistance, which is well within a usable range. So it's something electrical leading up to the injectors. I've checked the wiring for about the two feet leading up to them, but after that, it goes in to the wire loom that heads to the PCM.

Basically, long story short, I don't want to grab a whole other computer from Pick-A-Part only to find that isn't the issue at all. Given that the 454 uses almost the exact same system as the Duke does, any ideas on why the PCM isn't signalling the injectors to fire? I'd really appreciate any advice on the matter, thanks!

K2500, I'm sure it's the same (motor-wise). Anyways, I don't have a voltage meter capable of checking the brief "on-time" of the circuit, but that would be irrelevent... When I forced 12V through the wiring leading up to the connector, injectors fire just fine.

AlRIGHT.

Having taken the truck from it's original lack of fuel delivery (No fuel) to massive over-fueling (Too much fuel) to lean misfiring (Not enough fuel) I've finally got the issue figured down to one part, more or less.

Because I realized the fuse got wiped when I shorted the injectors through the battery, I had an added issue to contend with there. Replace the fuse for the injectors and now the driver's side injector works, while the passenger's does not. Here, however, is where common sense simply goes out the god damn window.

Because both injectors are treated effectively as an alternating pair, I can now rule out other sensors from the equation (Distributor signal, O2, Oil Pressure Sensor) as those faults would cause both to not work. Looking at the power delivery, I know that the driver's side was working, so to check if it was either power or ground, I decided to "bridge" the two power sides at one point, and then the grounds after that. Now, before you go hollering "But Tristan, you sex god, two injectors takes twice the power!" know that at idle, the injectors are "off" more than they're on, and they alternate back and forth. As far as the system is concerned, it isn't running two injectors at the same pace, it's running one injector "more often". Bridge the power sides, and the driver's injector simply cuts out, just like the passenger's side (Removing that bridge causes it to work again). Alright, I thought, a little odd, but I will continue to ground. Now, this is where things would be "different" for the electrical system. In this circumstance, we're assuming power is being supplied to each injector, who are then sharing the ground signal. This does affect amperage and signal, so it's not a direct comparison to "working right". However, once again, bridging the grounds simply wipes out the driver's side injector as well (Without blowing the fuse, or destroying the computer, as the injector will work as soon as the ground is removed).

So, basically I'm at a point now where I have as many variables taken out of the equation as I can, but the remaining solutions no longer make sense... Any more help Doc, or anyone?

Up until two minutes ago I'd have said your suggestion of swapping the connectors would've been pointless. After all, I knew when I shorted them, both injectors would fire no problem.

Switched the connectors and realized I owe you a sincere apology.

For whatever reason, even after switching the connectors, the driver's side is still the only one firing, so I'll have to pull the passenger's side and replace it. Thanks Doc!

As for bridging the power side, I know they both come from the same fuse, but I was wondering if perhaps one side's power supply wasn't making sufficient amperage to open the solenoid (Injector) up, so I was wondering if bridging it would highlight any power-side issues for the one injector. And agreed, bridging the ECM was a dicey move to be sure, but like you said, it's survivable if done for a short enough time frame.

Lastly, no, no spares or extra bulbs/marker lights of any kind.

Romeo wrote: Any more help Doc, or anyone?

Sorry bud, you lost me after the "sex god" reference.

Tristan, please read (and respond to) your emails!

OY, DON'T TELL ME WHAT TO DO, OLD MAN. lol

Sorry for the back-to-back-to-back post, but I took it out for a few laps around the block, and I've discovered a few things:

• It shifts hard as hell at the moment, no idea why, wasn't doing it before.
• If you go full throttle, it completely cuts out (Or sometimes backfires). If you ease on to the throttle however, it will go up and stay at full-throttle just fine.
• Part-throttle seems to have a little bit of both idle and full-throttle characteristics. Snapping on to half throttle will stall, but unlike full-throttle, it's still fairly lopey at partial throttle.

Help?

Actually, tied in with what you suggested, it has a low TPS Sensor code as well. So if the MAP is conversely being read "high" compared to the TPS, that could be it. Will try that tomorrow. Finally having given up tonight...

I'm frustrated as hell. Don't want to look at that stupid thing anymore.

Tristan, I have it on good authority that a shiny new gas cap will restore your truck as well as brighten your smile.

Gas cap seems relatively minor now, seeing as how I spent this morning saving my K&N from a small engine fire, burning my hand in the process.

Ok, now I'm fairly certain it is a fuel issue.

Romeo wrote: ...I spent this morning saving my K&N from a small engine fire, burning my hand in the process.

All of us who own Fieros (them things catch fire, you know) should always have a fire extingusher near by.

How's your hand? Shall we now refer to you as "Lefty"?

I know my scan-tool uses "Printer" connectors (About the best way I can describe them. They're the same size and pin-count as old-school dot matrix printer connectors were) to go from the tool itself to the adaptor. I wonder if I downloaded WinALDL and found a "Printer-to-USB" adapter if I'd even have to build the cord...

Oh well, just picked up the new throttle body ($500 later...) so I'll head out and pop that on first, then I'll see if I need to keep scanning.

Romeo wrote: Oh well, just picked up the new throttle body ($500 later...)

...

Hope that solves the problem!

I might, Gary. Just give me a little bit. My hand has healed up enough where I don't think it'd hurt to try and install the new TBI, so I'll head out and do that today and tomorrow (As well as to check what else was damaged). If it still struggles with fuel modulation, I will send you a message.

Thanks a lot for the offer!

Update: It's working.

Although I must admit, every now and then it has trouble idling (Although usually it runs flawlessly). I think it may be a vacuum leak, as, on top of those conditions, the transmission usually shifts late and hard (Which would imply the modulator isn't seeing enough vacuum).

(Happy now, Patrick?)

Hm, according to the interwebz, I have a 4L80-E. And I was fairly sure there was a vacuum leak somewhere, just thought it made sense for that condition to solve both symptoms.