Hi everyone, I'm a long time lurker and a first time poster. I spent the better part of yesterday afternoon chasing a no start issue in my 92 2.9 ranger. The truck ran perfectly until I went to start it up yesterday morning after attempting a TFI relocation to the radiator support bracket. My original one burned out on the distributor and I wanted to move it as it's starting to get hot here in eastern WA state. I'm sure that this is not what caused the issue as I fabricated a plug and play relocation harness (like the mccully kit), had the heat sink grounded to bare unpainted metal, and checked the connections several times to verify they were in the correct place. I also made sure to use RF shielding on the wire to prevent any interference. I've seen some sloppy TFI relocation jobs on the internet (not that mine's any better) that worked without a hitch according to those who did them. No wires were cut (I didn't want to hack up my ignition system wires) and the system has been returned to stock form to rule that out. I'm pretty sure that the engine control module gave up the ghost in a very irritating coincidence, most likely when I hooked up the battery after finishing my project (more on that later). Ironically, the ECM was the next thing that I was going to check out so that I don't get stranded. I guess the truck made that decision for me. Luckily, I have a company vehicle so I'm not completely in the weeds.

I think I have everything covered but am wondering if I missed anything. In my opinion, everything is pointing to the ECU The engine cranks over with no issues. This is behaving like an ignition or no fuel issue but I've ruled out everything else that could take these out. Here is what I checked yesterday:
-Fuel pump inertia switch is good.
-I can't hear the fuel pump run when the key is turned. The fuel pump was replaced within the last 10k miles so I hope it's not bad. I live near a busy street so the noise may have drowned it out. I'm suspecting that it may not be receiving any signal from the computer if it's not running. The plug is good. However, I took the air intake off and could smell fuel vapors coming from that part of the engine.
-Ignition coil is good (I swapped it out with a known working spare to verify).
-Swapped out and tested 3 different TFI modules that are sending a signal to the tachometer when I crank the engine. These should be good. I'll most likely buy a NOS one off of ebay (filko or motorcraft) since the quality of the new ones can be iffy. However the standard motor products one has given me no issues.
-Swapped out the fuel pump and EEC relays under the fuse box to rule those out.
-Distributor hasn't been touched and I've had no issues with misfiring. Timing should be good. I'm pretty sure that I can rule out the pickup coil. I'm not sure if these fail suddenly. Replacing the distributor is a last resort for me as that area is caked with oil and would be a crappy job. I might just pay someone to do that.
-I checked all fuses in both the engine bay and under the dash.
-Wiring looks good but I might delve into that deeper to check for rodent damage or a bad ground.
-Alternator was putting out the correct voltage when I was driving it yesterday. It is a NAPA reman one that was replaced fairly recently.
-I did notice that one of the wires on the negative battery terminal (one of the smaller ones that I think goes to the starter relay) was out of the clamp (I'm using the universal ones that NAPA sells). I think it worked it's way out when I removed/reconnected it for the TFI relocation. I didn't notice this until after my first start attempt which could have contributed to this problem. This could've led to a voltage issue that sent the ECM over the edge.

I'm 90% sure that this issue is the ECM. What led me in that direction is that I can't hear any of the relay/idle air control valve clicks when I turn the key to the run position. If the fuel pump is not running, then my thought is that it's not getting a signal from the computer. I plugged my code scanner in and was getting no response; it wouldn't even read codes. My next step was to pull out the ECM and check the circuit board. One of the capacitors is corroded and another looks like it's not that far behind. It looks like they have been going out for a while so this is not a recent thing. Other than that, the circuit board looks pristine. I was reading that the capacitors are what wears out on these old EEC computers and that this is a common issue. In addition, being out in the elements didn't do it any favors (110 degree heat and 0 degree winters). A reman one is on its way and should be here Friday. If this solves the problem, I've found some companies that will refurbish these that I will send the dead one out to so that I can have it on hand as a spare. It should be an easy fix for them and hopefully cheap.

I think I covered everything but if I missed anything, please let me know. Thanks for reading this long post. It's wordy but the devil is in the details for stuff like this and I wanted to make sure that everything's covered. I appreciate any help that any of you can give me.

 

Welcome to the forum

Try 50/50 test so no guessing
Take off the air tube to upper intake, make sure fan can't hit it
Spray fuel into the intake
Try to start
If it starts runs and dies then fuel delivery is the issue, spark is OK
If it doesn't start/fire then its a spark issue
50/50 no guessing on where to go next

In a 1992(1986-1994) Ranger spark is a separate system, ECM(PCM) only runs the fuel system
So if engine starts doing 50/50 test then yes, could be PCM issue

1992 should have a CEL(check engine light)
CEL should come on with key on, if not then PCM is not powering up
If CEL Come on then it should go OFF as soon as starter motor starts to spin the engine, this means PCM is getting a Timing pulse from TFI module and PCM will then start fuel injectors


You are using OBD1, have a look here: https://www.therangerstation.com/tec...ipped-engines/
2nd drawing shows the OBD1 connector in engine bay, find it, passenger side on main wiring harness

Same drawing has the Fuel Pump slot labelled
Turn on the key
Use a jumper wire to GROUND that slot, i.e. to metal ground or battery negative
You should hear a "click" from Fuel pump relay and Fuel pump should come on full time, you should hear it running
Try to start engine

The PCM normally grounds that wire for 2 seconds with key on, but just for 2 seconds
You are by passing that to ground it full time which PCM will do once RPMs are above 400(cranking is 200rpm)
If there is no "click" from engine fuse box area then fuel pump relay may be bad or no power
In 1992 it may be under the fuse box, green relay

 

Thank you for your help. I greatly appreciate it. I am still going to install the reman ECM when it gets here. I looked at the old ECM and saw that all three capacitors are starting to corrode (a common problem that's been starting to pop up on these older fords from what I've been reading). I'll try the starting fluid test tomorrow morning along with everything else you mentioned. It'll be useful to know if the ECM is still good so that I can keep it as a spare. I would not be surprised if one or both of the new relays (EEC and Fuel Pump) that I swapped in were dead on arrival. Same with the fuel pump itself even though it's relatively new. The quality of a lot of aftermarket parts seems to have gone downhill in the last decade or so. Hopefully it's not the fuel pump as that's a lot harder to replace compared to an ECM or ignition components.

 

The capacitors are not hard to replace, under $5 fix

I had to do Caps on my 1994 4.0l PCM a year or two ago, been running great
No fuel pump is a symptom of that, or its on all the time, mine did both, but several other running issue that came and went, took me 2 days to finally pull it out and look, but no other parts were needed, just the 3 caps