EECIV No-Code Output, solid test light.

Good evening, I come before you greasy and humbled, begging for knowledge.

I've been trying to get this wee pain in the arse to fire, but it's being...difficult. I've checked wires, cleared up some shorts, reconnected some cut lines, but when I got to doing the EECIV KOEO self test with the jumper wire and test light, I only get a solid light, no blinking. Am I doing something wrong? I have spark, the plugs come out smelling a little like gas, but way less than I expected. Someone suggested doing a TFI replacement, so I'm in the middle of that, but...what did I do wrong? Any thoughts?

I would check the timing and firing order. Spark and fuel but no fire is not likely a TFI issue. I would also check fuel pressure. Low pressure can get fuel to the cylinders but still prevent firing.

Appreciate that.

Today, after waiting forever, managed to get a new set of injectors into the truck. Took a little starting fluid, but it got up and ran solidly on its own for a minute. Surprisingly quiet, too, no misses. So, I shut it down, go to get my timing light, and now the little bastard won't fire. Cranks and cranks, but won't catch. Now, this thing JUST ran like a top, so what did I screw up? I AM suddenly getting an emissions light that wasn't illuminating before when I turn the key, but it turns off after 5 seconds. If I use starting fluid, it catches, but dies quick.

Suggestions?

You know where the OBD test connector is

Look here: http://www.therangerstation.com/tech_library/OBD_I.shtml

second drawing down show that connector, and a slot labelled Fuel Pump
If the key is on, and you GROUND that slot, the fuel pump relay will "click" closed and fuel pump should come on, you should hear the hummmm from frame rail and gas tank, 1986 will have two pumps.

Then try to start engine
Normally the Computer Grounds that wire to close FP relay, but only for 2 seconds with key ON, once RPMs are above 400, engine started, computer will ground FP relay full time

Also with fuel pumps running test for fuel pressure at the fuel rail, there is a test port that looks like a tires air valve(may still have a cap on it), because that is what it is, a schrader valve, works the same, be careful because there should be 30-40psi fuel pressure in there.
See if you have good pressure

If you don't hear any hummm then fuel pump relay or fuel pump fuse/fusible link could be bad
Fuel pump relay has a GREEN base, pull out the relay
Key OFF, test each slot in relay base, one should have 12volts, thats from the fuse/fusible link
Key ON, another slot should now have 12volts, thats from EEC relay, BROWN base

If it all tests OK then check inertia switch in cab, passenger side, just below glove box, it has a RED button on the top, push it down, if it goes down then inertia switch was Tripped, and should be replaced because it will trip again.

If inertia switch is OK then fuel pumps are the issue

Ah!

I've already tested fuel pressure, and it's sitting right about 39 psi with the pump running, 34 while cranking. No gas in the vacuum line by the pressure regulator. Both pumps are wired with a separate stand-alone relay, thanks to the PO separating them for some reason.

New news, too. I came back from the store, put the battery back on, and tried to crank it, and the little bastard started right up. But it was running solid, then bogging, then running high, then bogging again. So I'm assuming it's either IAC being screwed up, fuel filter is a mess from the old gas in the tank mixing with the new stuff, or the EEC finally giving up the ghost. I've heard that trucks do idle hunting really bad when those go out.

If idle goes high, above 1,000rpm, on cold start then IAC Valve is most likely not the problem.
Hunting idle can be an issue from removing power, disconnecting battery.

The EEC-IV computers "learn" IAC Valve voltage pulsing vs RPM, and that is stored in memory like Radio Pre-sets, and it is lost just like Radio pre-sets if all power is removed.
IAC Valve gets 12volts with Key On, the computer pulses the Ground wire of the IAC Valve to open and close it to set desired RPM, it then remembers the pulses needed for which RPM.
So if you change the IAC Valve or cut all power, computer has to re-learn pulses to RPM.

ECT(engine coolant temp) sensor is what the computer uses to set Choke or Warmed up RPMs.
A cold engine still needs high idle and Rich fuel mix EFI doesn't change that, but EFI does mean you can't use a choke plate, no Jets to suck extra fuel out of.
So computer "looks" at ECT sensor at startup, and while driving, if coolant is under 140degF then computer runs higher idle(via IAC) and richer fuel mix(via injectors), computer reduces idle level as ECT warms up and also leans out the mix.

Warm idle for manual trans should be 625rpm
Automatic 750rpm

Cold idle is temp based, freezing temps can be 1,300+ RPM, but usually about 1,000-1,100 is normal

When you turn on the key the IAC Valve will open all the way, full Ground from computer
If you don't touch the gas pedal
When you start the engine it should surge to 1,500+ RPM, then start to drop as computer sets "target" idle RPMs, i.e. cold or warm ECT RPMs

Failing ECT sensor can cause what you describe, they can be tested but at $6-$8 it almost is better to just replace it.
ECT sensor has TWO wires
ECT SENDER, has ONE wire, sender is for the dash board temp gauge only

Interesting.

Would the ECT sensor also cause the no-start condition after I shut the vehicle off, and try to restart it?

Yes, possibly, it could show cold engine start up instead of warn restart, so flood out(Choke) an already warmed up engine.

Would it show warm instead of cold? I mean, I can get the engine to run for about...oh, 2 minutes. I hesitate to run it much longer than that, just out of worry for the internals, until I can get it properly gone-through. I'm assuming a warm start would be hell to get a cold engine running.

I only ask, because the damn thing will just not start after I run it for anything from 30 seconds to 2 minutes, even with starting fluid. I mean, it'll burn the starting fluid, but it just dies after that.

If it won't start/fire with starting fluid then spark is gone, ether has a very low ignition point which makes it a good starting fluid, so even a weak spark should ignite it.

If fuel filters were clogged I would expect fuel pressure to start dropping as soon as engine started, then it would stall and not restart(on its own) until more fuel could pass thru the clogged filter, but starting fluid would get a restart and then stall again when it was used up

RonD said:

If it won't start/fire with starting fluid then spark is gone, ether has a very low ignition point which makes it a good starting fluid, so even a weak spark should ignite it.

If fuel filters were clogged I would expect fuel pressure to start dropping as soon as engine started, then it would stall and not restart(on its own) until more fuel could pass thru the clogged filter, but starting fluid would get a restart and then stall again when it was used up

Click to expand...

See, when it gets running on a cold start, it runs fine, other than the idle hunting and bogging. I rev it a little, it bogs, then comes back up, and only intermittently bogs. But once I've run it once, it just won't restart. It'll fire with starting fluid, but won't burn gas unless I've unplugged the battery and killed power to everything for at least 30 minutes.. So I'm confused as to what could even cause that at this point. I know in carbs, surging is usually fuel starvation, but the pressure stays up, and with this thing being fuel infected, I'm a little confused, and I keep leaning towards an electronic problem, rather than electrical, per se. That's why I was maybe wondering about the ECT giving a crap reading to the computer, causing it to hunt and then just not start.

The engine doesn't die mid-run, it just doesn't start back up once I've shut it off.

If it restarts with starting fluid then Spark is OK.

1986 will use a MAP sensor for air/fuel mix
At cold start the EEC ignores most sensors, it runs pre-set air/fuel tables based on 2.9liter engine and RPMs
Once cold engine starts and runs a minute or two EEC will start to use MAP sensor, so check its Vacuum hose for a leak.
And electrical connector for corrosion.

And I would open the EEC and check circuit board
Should look like this inside: http://www.auto-diagnostics.info/ford_eec_iv

You can see the 3 Blue capacitors inside, they can leak, which will cause air/fuel mix issues along with other odd problems.
Easy to see the discoloration and/or corrosion if one or two leak

So, I got the thing running, after a bit of a fight today and some fiddling with the dizzy. It idled about 900 for a good five minutes, started getting warm on the gauge, and then just flat out died. I'm assuming that the MAP wasn't doing its job at that point. Pulled the connector, and everything is green and gunked in there, so that's the first order of business. Hoses all looked okay.

Edit, I pulled the EGR connector, and it's a mess. The MAP sensor connector looks brand new. So, I'm not sure what's going on there.


I did notice, while it was running, that if I push on the brake, the engine tries to die. I also hear a hissing inside the cab that disappears with brake apply, so...booster's gone bad, I think?

I'm going to yank the EEC later today and check for those capacitors, but it wasn't idle hunting too terribly badly today.

Took me a couple days to get the time, but I got the computer out.

I've looked through, and I don't see any black caps that look shot, but that little silver bugger in the center of the board seems to have done something rather unpleasant to the circuit board itself, so I'm wondering if that might have something to do with it? I'd attach a picture, but the forum isn't letting me for some reason. It's a flattened silver rectangle, about the size of a fingernail, two legs, with "03S16 12.0Mhz EDC0686" printed on it. Both ends have corrosion or something spilling out of them onto the board, discoloring it.

Edit: Crap, this is the computer clock, isn't it?

It still won't start without some ether, and even then, it's iffy. The plugs are all black, still gapped, but when I pulled the wires, the crimps came right off on the plugs, so maybe that might have something to do with the miss, maybe the hard starting, too.

Sorry about being such a pain in the ass noob. Just really want to get this damn thing going, and I'm kind of in the woods on EECIV.

Also, an addendum.

Before, I recognized that the truck had a vacuum leak through the booster. It ran fairly strong while cold, even with the leak, but dies after warming up. Just shuts right down. If it's switching over to MAP control for fuel/air, would that extra air leak be enough to shut the thing down, or would it just run it faster?

Also, the spout jumper is missing, and I'm not sure where to find one. I'll probably just make a wire with some tabs soldered on, but I'd like something that's a little more weatherproof.

Today's joy is getting that jumper together, getting the computer back in, new plugs and wires and valve cover gaskets, hooking the MAP up, and checking to make sure I didn't completely fugg the timing and such on the truck, since it apparently requires the spout to run properly, and that plus an air leak and a possible timing issue would maybe shut it down if the distributor timing was a mess?

I'm going to have to TDC this motor and yank the distributor, aren't I?