No spark with SPOUT connected

[flwsock]

After a long fight with no spark, I unplugged the connector with the yellow wire coming out of it that attaches to the TFI (I think this is the SPOUT?). After unplugging it, I had spark. What does this mean and what do I do to fix It?

1983 Ford Ranger 2.8l V6 carb'd, 4spd, 4x4

Thanks

 

[Bird76Mojo]

Normally that means the PIP coil is on it's way out.. Not sure on your model though.

 

[flwsock]

Hi Bird, I should mention that I replaced the entire ignition system before finding this. New distributor, plugs, coil, ignition switch, ICM.

 

[Bird76Mojo]

You never know with today's ignition parts. Many are junk even though they're brand new. TFI modules are especially notorious for being junk from the get-go.

The best testing method I've found anywhere to determine if it's the TFI module or the PIP that's bad:

 

[RonD]

The engine should start and run with SPOUT disconnected, does it run?
Disconnecting SPOUT is how you set base spark timing

When SPOUT is connected the computer is now advancing the spark timing


TFI system is pretty simple but prone to failure

The sensor in the distributor, hall effect sensor, generates a PIP signal, basically it is the "Points" like in older distributor
This PIP signal goes to the TFI module
TFI module uses the PIP signal to unGround the Coil, which causes it to spark
TFI also sends the PIP signal to the computer so it can time the fuel injectors

The TFI module has an RPM advance calculator, so it advances spark timing based on RPMs, but has no "load calculator", this was known as Vacuum advance on older distributors
The SPOUT wire is the Load calculated spark advance sent from the computer to the TFI module, since computer has the throttle position sensor and MAP sensor its in a better position to calculate engine load

If the SPOUT wire to computer was grounded out that could cause TFI module to shutdown spark
So check it that has happened, use ohm meter to see if there is a short to ground

 

[flwsock]

With the SPOUT disconnected, the truck will run.

I'm not good with testing stuff with an ohm meter/multimeter. Electricity isn't really my thing. How would I use an ohm meter to see if there is a short to ground? If there is a short to ground to the computer, does that mean the wire is damaged or that I need a new ECU?

If it's not grounded, it sounds like I have a bad new TFI or Hall Effect Sensor?

 

[RonD]

Hall effect sensor works because you have spark

OHMs is resistance for electricity, inside the ohm meter is a battery, in OHMs setting the battery is used to pass electricity from one probe to the other.
If you touch the 2 probes together you will see 0 ohms because there is no resistance, its a direct connection
If you test each end of a wire you should see 0 ohms because wire has virtually no resistance

Vehicles have their metal parts grounded together
So if you were to touch a probe to bare metal on the engine and bare metal on the body then you should see 0 or very low OHMs
If you touch probe to engine metal and SPOUT wire is should NOT show 0 or low OHMs, that would mean the wire was bare somewhere and touching metal of the vehicle


If you have the old TFI module you can test if its SPOUT is grounded in TFI module and then test new one

Info here on TFI testing: https://therangerstation.com/tech_library/TFI_Diagnostic.shtml
Scroll down to the bottom

 

[flwsock]

It'll be a couple weeks at least unitl I get back out there and check the OHMS. In the meantime, what would you consider high OHMs? In other words, how many OHMS should I expect when I touch one wire to the engine metal and one to he SPOUT?

Also, should I test this with the key on? Or does it not matter. I just want to get all questions out of the way so when I finally go to test it I know exactly what I'm doing. I'm a noob with electricity if you can't tell.

 

[RonD]

You would test it key off and then key on, SPOUT Connector out, you are tesing the wire that goes to computer, not the wire that goes to TFI module, if it was shorted then SPOUT connector in or out wouldn't matter

set OHM scale to 1k, 2k, 5k or 10k whichever you have
Under 100 would be a short to ground

 

[flwsock]

Alright, back with an update.

We tested the SPOUT connector to the computer and came back with 55ish OHMS. Said ok, it's grounded out according to Ron since it's under 100. We took off the passenger kick panel to see if there was any corrosion. All wires checked out ok. We tested for continuity from the SPOUT connector to the associated wire to the computer and that checked out ok. I pulled the distributor out and tested the brand new TFI module -- it was bad. I bought another one and tested it -- also bad. I tested the original one fromm the truck I had originally replaced -- it tested pretty close to spec, so I reinstalled that one. It STILL won't start when it's plugged in.... but it WILL start without it plugged in.

I checked the EEC relay and it clicks when the key is turned on and a few seconds again when turned off.

The only thing left is the computer. I took the computer out and took it apart. I don't see any signs of anything burning out or otherwise. I've replaced the coil, plugs, cap, rotor, distributor (with hall effect sensor), tested the TFI, new ignition switch. The only thing left is the computer, right? Could something be wrong with it even if it visually looks ok? E.g. nothing burned out or broken?

 

[flwsock]

Bump. The only things I now that I can do now are replace the computer or EEC relay. Please advise!

Could the TFI still be bad even though the readings were close to those on the chart?

 

[RonD]

Just to confirm

Engine starts and runs with SPOUT disconnected
And stays running if you connect SPOUT while its running?

Just won't start with SPOUT connected

And you are using the correct GREY TFI Module not the Black one?

 

[flwsock]

Just to confirm

Engine starts and runs with SPOUT disconnected
And stays running if you connect SPOUT while its running?

Just won't start with SPOUT connected

And you are using the correct GREY TFI Module not the Black one?

The engine will start and run with the SPOUT disconnected. If I connect the SPOUT while the truck is running, it will immediately die. It will not start, nor run with it connected.

Yes, I have been using the gray TFI's. The two brand new ones were duds, so I returned to the original which reads reasonably close to the levels.

 

[Bird76Mojo]

I've read that newer TFI modules being tested on older testing equipment, the TFI will test bad due to the newer TFI modules using more modern electronics that can't really be tested with the older equipment. I'm not sure on the accuracy of this info though..

Did you try the testing method outlined in the video I posted?

 

[RonD]

SPOUT is the "vacuum advance" on this type of system, so it advances spark timing when it is plugged in, I think at idle it jumps it up 12deg or so

This advance is from Base spark timing set by the mechanic, you in this case

So lets look at it from the other perspective of base spark timing being incorrect, i.e. the crank pulley marks are not correct
You have set it as 10-12deg BTDC
So with SPOUT Connected it should go to 24deg BTDC or so, don't remember exactly

Try moving Base timing to 5deg BTDC engine should start to stall if not marks on pulley are not right

Grasping at straws here, lol