Mystery No-Start Thread

[brettwilm]

Hi Mudders, brettwilm here. My 94 FZJ80 hasn't started in two months. I've thrown over $1000 at it, and a crap-load of time and effort, some of which I may not remember the exact details of...I would really appreciate your help.

The problem began immediately after a session when I replaced the distributor o-ring, EGR and PCV hoses, and the air intake hose. Immediately afterword, the truck ran briefly (test drive around the block) but then quit as I slowed approaching a stoplight. Ever since, it cranks nicely but won't start. My initial suspicion is that I caused a short in a wire somewhere.

Since then, I've replaced my spark plugs, wires, distributor cap and rotor. I've replaced the ignition coil with no effect. I've replace the VAF / air flow meter. I've tested the EFI relay and associated fuses. I've tested the ignition fuses under the control panel. I've successfully actuated the fuel pump using the test connector. I've had a trickle charger on my battery, which shows over 12 volts on a multi-meter and is only about six months old. I've adjusted the ignition timing.

At start, I have a CEL. When I do an OBD I pull, I get a code 1 "normal."

I was loathe to start a new thread without doing my due diligence. I've run the emergency troubleshooting procedures in the FAQ, and investigated the following threads.

Anything else to try before replacing ECM? Help in northern New Mexico?
Think I killed my ECU, help!!!!!
Intermittent problem getting power to my ECU. Need some ideas.
Bad ECU?
No Fuel = dead ECU. Brother, can you spare an ECU?

I haven't found the fix, although I'm sure I haven't exhaustively tried everything therein. Oh yeah...I had the truck towed to the dealership where it sat for three days and $500 of shop time, and they concluded I needed a new ECM. I don't think that is the right answer (although I haven't tried swapping one).

I do have the 1996 FSM brought to me by BirfMark via ElPolloBlanco, and also bits of a 1994 FSM I have been assembling with Adobe Acrobat, and *gasp* the Haynes Repair Manual for 1980-1996 Cruisers.

 

[Dragos80]

Reading so many threads alike, it is easy to spot a pattern.
Start by checking the fusible link, then move on to other things (fuel pump for example).

 

[brettwilm]

Reading so many threads alike, it is easy to spot a pattern.
Start by checking the fusible link, then move on to other things (fuel pump for example).

Thank you Dragos80, per this link the fusible links have checked good.

 

[Dragos80]

Ask @Qball about his recent ECU swap idea.

 

[brettwilm]

I intend to work systematically through each of those mentioned threads, and then back through the FSM. I will report what I find.

 

[Irish Reiver]

I haven't read the threads you link to so i might have missed it but have you established if you have Sparks at the plugs and fuel at the injectors? I would assume one or both is absent - knowing which one makes troubleshooting a little easier.

Sent from my SM-G920T

 

[brettwilm]

Reading so many threads alike, it is easy to spot a pattern.
Start by checking the fusible link, then move on to other things (fuel pump for example).

I checked the fusible links as described in the FAQ for Emergency Troubleshooting Procedures. Under Scenario 3:
Turn key, engine turns over but does not run: "Fusible Links" it describes the following check:

"Main" Fusible link, critical as it is upstream of the 15A EFI fuse under the hood, you can test this one from the drivers seat by turning on the radio, headlights, ac/heat fan, defrost, stop light, tail lights and telephone, if any of the above work then this fusible link is good,
With key on, engine off, all checked good. I don't have a phone.

"AM1" Fusible link, critical as it is upstream of the ignition switch and provides the power for to the starter solenoid, you can check this one from the drivers seat by checking the horn/hazards, dome light, diff locks, rear heat, turn signals, cigarette lighter, or wipers,
If you have the hazard & horn but none of the others check the big 50A AM1 fuse in the under hood fuse box (50A AM1 fuse not to be confused with the AM1 fusible link) Might not be a bad idea to stock a 50A fuse incase the big AM1 fuse blows
With key on, engine off, all checked good with following exceptions: I don't have diff locks (only standard
shift center diff lock), and rear heat only worked in "Hi" not "Lo". Could be unrelated.

"AM2" is probably the most engine centric, it provides power to the ignition switch, the injectors, the igniter, the ignition coil, the distributor, and the alternator control system, if you get the yellow light on the volt meter with “key on engine off” this fusible link is good,
With key on, engine off, I have a red not yellow light on the volt meter. IDK if that matters.

...All I have time for tonight.

 

[LandCruisinMy93]

You need to check for fuel at the injectors as mentioned. If you have fuel at the injectors you need to ensure you have spark. If you have spark and fuel you have a timing issue. I have a spare 93 ecu you can use to check your ecu. You'd have to arrange shipping.

 

[Reelitchy]

Do a search for
'94 FSM
In the titles, will give you a link to 94 fsm in Google docs

 

[brettwilm]

This morning I confirmed I have a spark on #1 (removed plug from engine and, re-installed in spark plug wire/boot, held near ground while my wife cranked the ignition). This being the first time I've done that, I can't say whether it is "weak" or "strong". I held the plug about 1/4 inch (1cm) from ground--further and it would not spark.

 

[baldilocks]

In post #1 you said that the trouble began after you changed the distributor 0-ring. My hunch is that your timing is now off. If you plan to get your 80 running and keep it running, you absolutely need a copy of the 1994 FSM.

 

[Alleycats]

I was thinking the same thing, when you reinstalled the distr. maybe it got off by a tooth?

In post #1 you said that the trouble began after you changed the distributor 0-ring. My hunt h is that your timing is now off. If you plan to get your 80 running and keep it running, you absolutely need a copy of the 1994 FSM.

 

[Methusalem]

Maybe you already checked this, but when I had the same problem (turning, but not starting), for some unknown reason the fuse box under the EFI fuse was melted. I didn't see anything at the outside.

 

[Wayne]

When you were replacing the EGR valve did you disturber the main engine wiring harness just below the EGR valve? It's known to become brittle and cause electrical problems with the engine. Did you for any reason disconnect the Throttle Position Sensor and maybe didn't reconnect it fully, causing it come loose and lose contact? If you're getting fuel to all six injectors, it has to be an ignition, timing or sensor problem.

 

[brettwilm]

I just bought a nifty new timing light. Placed the red clip on the pos, black on the neg, and inductive pickup on my #1 spark plug wire. Crank and no flashing.

 

[brettwilm]

Ops-checked the nifty new timing light on another vehicle and it flashed just fine. Hmm. Maybe the spark is weak on my truck....

 

[Dragos80]

It's time to revisit the distributor.

 

[brettwilm]

OK just took my 1/2" drive and my 30mm socket and cranked the harmonic balancer aka crankshaft pulley around to TDC. Removed distr cap and rotor is at 05:30. So I cranked the crankshaft around another 360 and now it's TDC again and rotor is up at 12:00. This ought to be in the ballpark where it's not a timing issue, right?

 

[ppc]

No matter if the timing is off or not you still should have had flashes from the timing light. You have no spark or is intermitent.

 

[brettwilm]

In post #1 you said that the trouble began after you changed the distributor 0-ring. My hunch is that your timing is now off. If you plan to get your 80 running and keep it running, you absolutely need a copy of the 1994 FSM.

Is it unreasonable to look for a single-file, coherent 94 FSM somewhere? Or is dealing with a 94 FSM in 50-some discrete .pdf files the price of admission? If there's gonna be a hazing process, I'd just like to know.