dies once...and only once.

[Spitfire1975]

Ok. The problem came back. Completely random. Last night it was running fine and turned it off. Went to start it again and nada. Nothing doing. Messed around with the coil connection and checked the coil spark, tried to restart it and it started just fine, no problems. Turned it on and off several times with no issues.

My wife took the truck to work today and got there with no problems. Came home for lunch and went back to work with no problems (4 miles each way). On her way home it flat died on her while driving about 25 mph. She was almost home. (30 seconds from the house) Went to get her, popped the hood, and had her try to start it. Nothing. Pulled a wire to check spark and the it started just fine. Even seemed to run fine with one plug undone. Turned it off, hooked up the wire, started it again and drove home. No problems.

SO.....I replaced the TFI last night after the reoccurrance of no start. It was used, so I guess it could be bad as well. I have another I will try. Coil seemed to have a nice steady crisp blue spark.

What else could I be facing? loose ground? All seem to be good.

 

[Spitfire1975]

Would a bad EEC Relay cause the engine to shut off when it gets hot?

 

[Spitfire1975]

Or perhaps even a loose connection in the ignition switch in the steering column?

 

[IMenriched]

yes bad relay could...if it is older. Has it been dryer lately with it running good...then with the return of symptoms has it been wet? the relays can loose their ability to seal out moisture over time...then corrode from the inside out.

more so suspect that you have a bad connection or ground. but a new TFI couldn't hurt ..but if it tests out good ... try the relay 1st, they're not too pricey, relatively speaking.

have you checked the ground wire near the ECM,(computer/brainbox), passenger side kick panel, forward of the door....there is a ground there too that sometimes gets funky.

as to the steering column....yeah that might be a possibility. If all grounds and connections are good, then maybe investigate further into that.

 

[Spitfire1975]

Dry on all occasions (an amazing feat here in the NW).

I just reconnected the PCM ground, so that's good. All the other grounds seem to be secure, I need to clean the oil off of the main engine block ground and may add a couple more coming off of the transmission (had a transmission guy tell me that the grounds aren't all that great on these trucks and the additional grounds will help save the transmission bearings. Something about electrolysis pitting the bearing surfaces)

I put in an older relay to see if it makes a difference before going and buying a new one. Just need to drive the truck around for a while. The odds of two doing the exact same thing are pretty slim I think.

 

[Spitfire1975]

It died on me again today, this time I haven't been able to get it started. No spark to the wires, no power to the coil.
Blowing a code 67 with the KOEO and only a code 67 (Park/Neutral circuit fault).

Is this going to be the switch on the clutch pedal gone bad or something down by the transmission? (Toyo Koygo 5 spd 2wd)


Any quick help would be appreciated. The truck is sitting right next to a really busy road.

 

[Spitfire1975]

Got it home last night. Not quite sure what I did to it.

The wires going to the transmission DO need to be replaced. I moved them around and the code 67 went away. Still didn't start. Scratched my head in confusion looking at the engine and it started? Then it died 5 minutes later.

Checked codes and got an 11. System clear.

Played around with it some more. Main ground to engine block is DIRTY and was a little loose AH HA! FOUND IT! Nope. crap. It didn't make a difference. Wouldn't start. Replaced the computer for shits and giggles. No start. Checked power to coil again. No power. Checked again. Now there was power. Wtf? Started right up and drove it home like nothing was wrong.

Where can I get a wiring schematic for the start/run/ignition system?

 

[Spitfire1975]

All the power in this truck is originally routed through the starter solenoid/switch (is this the "power distribution box" labeled on the schematics?). Could this be the problem? When the truck stops, NO power is making it to the coil, so obviously there is something that is getting hot and not working again until it sits awhile. Fusible Links (I don't know how those work)? some other switch, relay, etc that I don't know about? It is not the TFI or EEC relay.

Shaking, jiggling and swearing at the wiring connections, etc doesn't help any.

 

[robertc1024]

Oh man - I just realized it was you from the Schematics posts on the General Discussions. After re-reading this thread for about the fourth time I had a couple of thoughts. If it's dying immediately, it's got to be electrical - as it seem's you've discovered. After all the stuff you've changed, it sounds like you might have a bad connection/bad wire somewhere. If you've got a busted wire and everything shrinks when it's cold, you get a connection. It runs for a while heats up, everything expands you get a break. I'd start ohming wires out very carefully when it won't start. Or trace power back with the ignition on to see where the power stops.

 

[Spitfire1975]

Oh man - I just realized it was you from the Schematics posts on the General Discussions. After re-reading this thread for about the fourth time I had a couple of thoughts. If it's dying immediately, it's got to be electrical - as it seem's you've discovered. After all the stuff you've changed, it sounds like you might have a bad connection/bad wire somewhere. If you've got a busted wire and everything shrinks when it's cold, you get a connection. It runs for a while heats up, everything expands you get a break. I'd start ohming wires out very carefully when it won't start. Or trace power back with the ignition on to see where the power stops.

Yeah. That's why the hunt for the diagrams. Problem is getting it to not start when I want it to. I am going to take a real close look at the starter relay/switch and go from there. I am new to the wiring issues and it gets confusing as to where to start and what is doing what.

 

[Spitfire1975]

If I am following it backwards (power supply) I should be able to just use a test light, right? Ground the negative to the frame and probe wires with the positive looking for it to light up?

It's a dumb question, but I may as well ask, if not for my own info then for someone else.

 

[Spitfire1975]

Just ran it for 1 hr & 45 minutes straight. It stayed running the whole time. Jiggled wires and connections, computer connections, etc..... no difference. I did shut it off once to find out which wire was controlling what off of the starter relay (power distribution box??). The only wire that would duplicate the problem was the yellow wire that runs from there to the eec relay to the computer.
Don't really know what to make of that.

 

[Big Jim M]

I think I'd be wiring the park/neutral switch completely out of the loop.. Just to see if it does that crap again. I'd find the wires under the hood and short them as high as I could.. At least I'd be finding the wires at the switch and put a meter on them to make sure of what I had.
Big JIm

 

[Spitfire1975]

I think I'd be wiring the park/neutral switch completely out of the loop.. Just to see if it does that crap again. I'd find the wires under the hood and short them as high as I could.. At least I'd be finding the wires at the switch and put a meter on them to make sure of what I had.
Big JIm

The park/neutral on the transmission? That would be simple enough to do. I need to replace the whole run of wire anyway. Just connect the two cut ends as though the switch didn't exist?

 

[Big Jim M]

Yep!
Big JIm