neoworm0

No, Got a few keys on there but nothing too heavy. Who knows though. I'm ready to try anything. thanks.

neoworm0

Ok well this thread has been dead for awhile but the issue has slowly gotten worse. It's graduated to shutting down while I'm on the highway. Drove it up North for Xmas and it happened 8 times on the way.

Well today I pulled the "Circuit Opening Relay" and I found some corrosion on the "STA" terminal. This seems like a likely cause to me as a bad connection there would shut down the whole MFI system. Got my fingers crossed. I'll post up in a few days or a week if it doesn't come back.

rdharper

neoworm0

Not sure I understand your post "rdharper". Are you trying to tell me it may still be the VAFM? I replaced it awhile ago with another one from a truck that had no issues. Also the truck just shuts down instantly. No bucking, sputtering etc. More like someone just turned off a light switch.

I have a good feeling about this COR, but if it comes back I guess I'll try the VAFM again? Getting pretty frustrated. Only reason it hasn't gone to the shop yet is because I need it for work.

rdharper

Sorry for questioning your replacement check with the other VAFM. Its just that the time-constant of slowly getting worse, and the symptoms... sudden shutdown... that is what happens with the AFM, as I've said.

So can I assume the when you tried the other VAFM, you were able to start the truck and run it... and eventually got exactly the same symptom?

If so... and that other VAFM worked with no problems in the other truck... then I am steering you in the wrong direction.

One thing that convinced me to tear off the top of the VAFM and inspect the phenolic and swing arm, was playing with an ohmeter and manually moving the air gate. You could see the discontinuity as a flick on the ohmeter.

Anyway.. keep us posted.

neoworm0

Don't be! I just wasn't sure if that's what you were getting at.

I am assuming that the VAFM that I replaced it with is good. I was told that the truck it came out of had no running issues. Yes I was able to start it. In fact the truck always starts again right away. When I replaced the VAFM the problem was still there.

I have driven the truck a few hours today and so far it's running well. Hasn't shut down yet. Time will tell. I will definitely post if this solved the problem or not.

neoworm0

Ok well it's been a week today and so far no recurrence. I think it was the "Circuit Opening Relay". Of course I just jinxed myself didn't I?

Thanks everyone for the insight and suggestions.

Jay351

fingers crossed on this bastard eh

neoworm0

Everytime I start it up I expect it to start doing it's usual dying routine. I'm like "Pavlov's Dog" now.

Jay351

hehehe, your truck has quite the personality

neoworm0

Well so much for that. It did it again this morning.

Got a coolant temp. sensor on order.

Jay351

****! Here's hoping this is it *knocks on wood*

ozziesironmanoffroad

hows your fuel pump? did you check that? wait a sec.... the whole engine shuts down, correct? do the idiot lights come on, or do those die as well?

neoworm0

Fuel pressure was checked at Toyota and everything checks out fine. Engine jut dies, I don't lose electrical.

ozziesironmanoffroad

id get a second opinion. ill bet you anything its a fuel delivery problem.

williemon

I know you checked harnesses already, but my 90 runner has an issue with the wires going into the distributer. Sometimes it will crank but will not hint at starting. It just spins. If I wiggle those wires, it starts. Once it actually died at a stoplight. Would not start. I wiggled those wires and it started up. Just something to look at. It almost sounds like wireing/connection issues. You work on it, jostle wires and connectors and the work ok for a bit, then corrosion, loosness sets in and the bugs are back untill you jostle them again.


Why was one plug so fouled and wet? If That cylinder is dead, or the injector is spitting too much fuel, the cylinder will exhaust rich and could fool the o2 sensor causing it to think the system is all rich. It could then lean the mixture untill its satisfied but could render the other 5 cylinders that were ok to be more lean now. That could increase the posibility of pinging and may lead to other symptoms too.

neoworm0

There's no doubt in my mind that it is a fuel delivery problem. There are a lot of things that determine/affect fuel delivery besides the fuel pump. The coolant temp. sensor for instance.

I think the problem is likely oil leaking past the valves fouling that plug but I like your theory. The cylinder isn't dead but it could be a bad injector. If this Coolant temp. sensor doesn't do the trick I'm going to look into that. How though. I guess the only way is to pull the injector and get it tested?

ReneB64

I have 240,000 miles on my 3.0 4 x 4, having error 25 all of a sudden, had recently replaced egr, not sure what problem can be.

neoworm0

Not trying to be a dick, but would you mind starting another thread for your problem. Got enough of my own without cluttering this post up too much. Thanks.

neoworm0

Not the Coolant temp. Sensor. Rechecked a bunch of grounds tonight. Realized I missed some the first time. Checked the EFI Main Relay ground and got a super high resistance value. Just not sure if I'm doing something wrong. Going to confirm it with a mechanic tomorrow. Could be the problem though I think. Maybe the wire is toast.