Mountain Cop

***EDIT: SOLVED, SEE POST #4***

I've searched already, and I know that there are a lot of threads out there that have similar symptoms, but either they just died without resolution, or they ended up being a different problem.

Here is the situation:

Brand new 22re, less than 1000 miles on it. Was running like a top, but over the last couple of days prior to this issue, the check engine light would blink occasionally and when it did, the engine would cough, as though it wasn't firing momentarily. There would be no stored codes.

Then, after driving it around doing errands, I started home. It was running better than ever, and then it suddenly stopped. I was able to coast to a turnout. When I turned the key to start it again, the check engine light didn't come on like it normally would. The truck cranks over with a vengeance, but it wouldn't fire. I had it towed home and started diagnosis.

First, I determined that the truck wasn't getting fuel. Using the 4crawleresque jumper in the fuel pump test location didn't have an effect. Running 12v directly to the blue wire under the passenger's seat (+ to the fuel pump) resulted in fuel pressure, but the truck still wouldn't fire.

I poked around a bit more. The ECU wasn't getting power, which makes the lack of a CEL make a lot of sense. By applying power to the "Batt" location on the ECU, my CEL became operational. By also applying power to the fuel pump, I was able to turn the truck over and get it to fire and idle for a few moments. It then died again.

What am I missing here? It acts like the ECU fuse blew, but it tests OK. Obviously, the ECU isn't getting power.

Can anyone think of another test for me to try? I'm open to any suggestions here.

Thanks in advance,

MC

92yoterDD

How did that power and ground for the ecu look? You could be experiencing voltage drop on those if they are corroded. Also there is a relay behind the passenger kickpanel that powers alot of things when the key is in the on position. I cant remember what that relay was called now but maybe someone whos does will chime in. If it were me I would get a test light and check every fuse. Then try swapping around the relays in the passenger compartment.

Mountain Cop

The connections at the ECU look good. In fact, I recently cleaned them and coated with dielectric grease. Circuit Opening Relay (inside passenger's kick panel, really more behind the stock speaker location), seems to be working. When get the truck to start by jumping + directly to the fuel pump and the "Batt" terminal of the ECU, it will start and run for a couple of seconds before dying (a common symptom of an unplugged or bad AFM), I am theorizing that whatever killed the power to my ecu also (or thereby?) killed the power to my AFM, which is thusly not providing the necessary signal to my ECU. Main relay has power and is operational. Perhaps this question is in order: What feeds power to the ECU? Is the circuit Ignition Switch>Fuse>Main Rely>ECU, or is there something else to consider?

It really is tempting to try to simplify this whole thing and just start over with new fuse blocks and a simple switch panel.

Mountain Cop

I began to check my connections at the engine bay fuse block, and found that the screw holding the red/blu wires to the 80A main fuse was loose. I tightened it, and everything runs as it should.

Terrys87

iTrader: (1)

It is always nice when someone post their fix. Doesnt always happen. Thanks for the info.

Disney

Mountain Cop, I think I am having the exact same issue. Would your truck start and run for ~3 seconds before dying? When I first started working on this issue, I could get it to run with starting fluid for a while then it would take off and run by itself. Did you ever try that? I hope mine is the same fix! I've been at this for over a month!!!