Advice on 1990 XLT M5OD 2.9l Mystery

[Maggrett]

Hello everyone! I have got to get "Buck" back up and running and I'm hoping someone can point me in the right direction.
I have a 1990 Ranger XLT that has been nothing but a blast to drive until two days ago. Always started right up, idled perfectly and drove great.
The other day coming back from a longer drive, I put it in neutral as I was opening my garage door and it died. It has not started since. Here's the facts:
1) The tachometer needle had begun to jump erratically a few days before it died, but the engine still was running great, not in sych with the tach jumping. I figured it was a cable that needed lube or something, but now I'm not so sure
2) Fuel pump powers on normally
3) Inertia switch not popped and is working
4) It has plenty of gas
5) Sprayed gas into the intake without effect
6) Multi metered the coil and it's within specs
7) Coil is getting juice, but not sending to distributor when ignition is on
8) Pulled Codes 18, 95 from non running test

My question is...what now? Can this be a SPOUT connection issue? I can't find mine for the life of me in the engine compartment. All help is greatly appreciated!

 

[adsm08]

Coil won't fire (send juice to the distributor) unless the engine is spinning.

You issue reads a lot like a bad TFI module, which is common enough on the 2,9. It is bolted to the back of the distributor and is responsible for firing the coil, and relaying engine speed and position information to the computer for injector control, so when it dies the engine won't run.

A failure in the SPOUT circuit will not keep the engine from running, but it will lock the timing advance at whatever it is set to mechanically, so you would have low power when driving, but the engine would run.

 

[Maggrett]

Thanks ADSM08. Would it really just suddenly die like that without any warnings? I will pull it and run the multi-meter on it as my next step.

 

[PetroleumJunkie412]

thats exactly how a TFI dies....

Look into a remote mount kit.

Also, Motorcraft brand name only.

 

[adsm08]

Thanks ADSM08. Would it really just suddenly die like that without any warnings? I will pull it and run the multi-meter on it as my next step.

Yeah, like PJ said that is pretty much exactly how they die. Sometimes you get one that just doesn't like being hot and will kill the engine once it heat soaks, but starts working again after it cools off. A lot of them just die.

There isn't a ton of diagnostic component testing you can do on a TFI with a multimeter. Most parts stores have a machine that will test them, but those are not loaded tests, and when you have an issue like this I do not consider the module passing the bench test to be definitive proof that it is good.

When I still had 2.9s I kept a minimum of two spare TFIs and the tool to change them in each vehicle.

 

[Maggrett]

Thanks guys. I found some voltage values to test and some were off. Coupled with your advice, looks like it's time to get a new TFI module.

 

[Maggrett]

Well, that was it! Fired right up like it usually does. I'm so glad it wasn't the fuel pump. Done that job before on a Bronco XLT. Not fun, nor cheap.
Thanks very much for your advice!

 

[PetroleumJunkie412]

Well, that was it! Fired right up like it usually does. I'm so glad it wasn't the fuel pump. Done that job before on a Bronco XLT. Not fun, nor cheap.
Thanks very much for your advice!

Listen to adsm08 and me both... carry a spare and the tools to change them if its not remote mounted. They have a habit of dying at the worst possible time.