2.3L ('83-'97) 1990 2.3L No Start and I'm baffled

[Ceej]

Howdy,

I drove the pickup out to the back pad last fall, started sanding on it to prep for paint. That was in September. Went out this spring, and surprise, the ten your old battery had died. Put a new one in it. Spins over fine now. But no start. Have spark, have a solid 40# of Fuel Pressure at the rail.
I hooked up the Black wire that has a connector with the Black green. There is a second wire that I'm having an issue tracing. It is in the same two conductor connector, Black/White it appears. Both blacks that come out of the other side of the connector are landed at the battery. Maybe I got that wrong?
I don't find the Black/Wht anywhere on my schematics. Is it supposed to be tied to battery ground? The Black/Green is, and that should be allowing the injectors to fire.
I have spark, I have pressure, but no indication that the Fuel injectors are firing. Not a pop. I'm thinking I connected both small black wires to the Heavy black at the battery that is the main ground in error, and that the Black/White actually connects somewhere else. The 89 Schematic shows the Black/Green. No Black/White at the battery. The '90 Schematic doesn't show anything tying in at all. The date for the truck is Late October '89.

I must be missing something.

Thanks for any help,
CJ

 

[SenorNoob]

Can you follow the wire? I suspect it goes to the alternator. That wouldn't cause a no-start tho.

 

[Ceej]

Sorry, had a little medical situation. Better now. Finally found a proper schematic that shows my particular pickup. Gotta get it running, as the BB is killing my fuel budget.
The fuel injectors run through various safeties, so I'll need to check each of them out. Finding the sensors is a challenge. They really buried the Temperature switch.
I'm a bit iffy understanding the EEC. I have spark, so I figured I should be getting signal to the injectors through the EEC relay, (Brown.) Found that under the fuses on the passenger side.
The Black/green and Black/white are supposed to go to the ground side of the battery, so that's right.

So is this something I can troubleshoot with a volt meter? It looks like the EEC breaks the circuit via the EEC relay.

CJ

 

[Ceej]

I have 12 volts to the injectors, but no pulsing at the switched side of the connector. Stays at 12 volts. From what I see, there are no components between the Switched leg and the Computer, which should be grounding the injector legs. I have spark on the combustion coil, but not the exhaust (Waste spark) coil pack. 8 plug system. This tells me I've lost a ground someplace, or??
The switched side goes through the block temp switch, and I though some other devices. The new schematic is hard to follow. And I'm having trouble following the EEC pin out. My eyesight is pretty poor closer than three feet due to eye surgery. Not that it was good to start with. There is supposed to be an eight pin connector between the injectors and the control module.
Where next can I look for this? If the crank position sensor wasn't working, I'd think the passenger side coil wouldn't be firing.
I must have lost a ground somewhere.

Thoughts?

CJ

 

[2011Supercab]

The exhaust coil doesn't fire until the engine is running, above 400rpm I think.

 

[scotts90ranger]

It's supposed to be the other way, the exhaust coil is primary and intake is secondary

I'm kinda stumped but if the injectors aren't pulsing then it might not be getting a good rpm signal. There's two sensors in the crank sensor, one for each of the vanes on the balancer, you might have lost one half of it...

 

[Ceej]

Thank you! I'll get in there and dig around some more!

CJ

 

[Ceej]

I worked my way all the way back to the computer. Time to open it up and check for bad caps. Had fun figuring out where everything was. According to my Schematic, the Tan and White wire are contiguous from the 8 pin connector, back to the Engine Control Computer.They don't go through the large round firewall connector?

CJ

 

[Ceej]

I'm still chasing the issue. I'm back to the EEC. Opened it up and replaced the caps. Two were completely shot. There was damage to the board, or so it appeared.

The replaced cap is at the far right of the "damaged" trace. The trace appears to have been purposefully cut though. See break where it's curled up. I have continuity from the cap back to the first two SMD's.
Unfortunately, I don't have a schematic of the EEC. This is PN E9TF-12A650-A2A if that is the correct identifier.

I cleaned the conformal coating off the trace where it appeared to be damaged.

Does anybody have a schematic for this application? Should this trace be cut, or no? I put a jumper at the location, but the Injectors still didn't fire. They still have 12 vdc at the injectors all the time, no ground signal from the EEC. Are there more than two layers to this board? I'm about to give up and order a replacement EEC and hope they get it right.

Oh, and I replaced the Crank Position sensor.

1990 Ranger 2.3L Manual.
CJ

 

[pentode]

Few questions- what's going on here?

It's hard to make out - is that just a spot where you didn't scrape off the conformal or is that the cut spot you're referring to?
Also, it looks like there's a thin trace leading to the same pin as that wide trace that I circled. Is that correct?
It looks like there might be a blob of corrosion on or attached to one of the pins of the cap you just replaced. It's probably nothing but that's not shorting to the adjacent trace is it?

 

[Ceej]

You've circled the break I was referring too. All you see next to the cap is a bit of Resin I didn't clean off. I think. To the left of the trace side leg of the cap.

CJ

 

[pentode]

Each edge of that trace looks lifted, like maybe it burned through right there, although the board underneath looks fine. I'm going to have to look through my files to see if I have a schematic but hopefully someone has a high res pic of that board.

 

[Ceej]

I have continuity between this points From the arrow to the three dots.

I jumper'd from here to here.

It didn't fix the issue, so I removed the jumper. No clue what the smd ceramic caps are that tie into the circuit, Can't read the printing us on them.

Is there a schematic for this computer?

CJ

 

[pentode]

I don't want to jump the gun - can you test that cap you removed for a short?

I didn't find a schematic yet in my stuff but there must be one out there.

Edit: I can't bring myself to believe they brought that big trace out and didn't intend it to connect to the other big trace so I'm wondering what that circuit does. It's gotta carry some current so I'm wondering what might have been cooked upstream.

 

[SenorNoob]

It looks to me like a component is missing where the initial red circle is.