After months of hard work (engine rebuild) I got my old rig back on the road. After getting the timing set on the new engine it had an issue with loss of power.. that turned out to be the TPS. I messed with it and got it to work just before the big trip! I drove about 2,000 miles before she gave up and left me stranded 140 miles from home.

I was driving home when the engine suddenly shut off.. I coasted to the side of the road and tried starting it. I wasn't getting anything! Suspecting the worse I took a quick look under the valve cover to see if there was any obvious damage.. I found no issues or leaks. I was at a total loss.

I messed with the engine a little trying to pinpoint the problem.. I checked for spark.. ignition system seems to be working fine. I checked for fuel.. all I could do is hear for the pump (no noise) and since I didn't have the correct spark plug socket I couldn't check the condition of the plugs or to see if it was running too lean.

I unplugged the TPS and Air Mass Flow Sensor... after doing this it would start right up and idle for 3 seconds before dying.. I tried giving it gas at start up but this just caused it to die faster. I plugged everything back in and tried it again after returning from the ATM to get money for the tow truck driver. While waiting for the driver about 30 minutes after messing with it I started it up and it idles without dying.. It was running rough like it was running on 3 cylinders.

I decided to have it towed the last 140 miles to my house instead of limping it home and blowing up the engine on the climb back home to 6,500 feet.

Just last week I was in Colorado on vacation with my girlfriend.


The last leg of my trip she gives out and decides to leave me in the desert.


Last night I couldn't find any tow truck companies willing to haul me up the mountain.. The going rate was $50 hookup and $4.00 a mile.. I had 140 miles to go. I got a call back from one guy willing to do $375.00 cash! (Randalls Towing in Apache Junction, AZ)


Hope to get my rig back to 100%, everyone is telling me to give up on the old toyota and get a new car but I have a history with her, she's paid off, and cheap (when I'm not having it towed).

Thanks for any help. I'm leaning toward the fuel system.

 

Fuel pump main relay?

 

Update: After spending hours trying to find and fabricate a way to check my fuel pressure I have found...

I do have fuel pressure! My fuel pressure is ~38psi at idle and drops to ~25psi 5 minutes after shut down and ~20psi 10 minutes after shut down. I am testing from the cold start injector line off the rail. (see pictures)

I need to know if the pressure is good and the drop over time is normal.
Does this mean the fuel pump and relay are good?

This is my custom pressure tester adapter from an old cold start injector line and a tire valve stem.




Thanks for any help on this. This is my only transportation right now.. Thanks for any help!

 

Anyone?? I'm still at a total loss on this one. I was thinking it could possibly be the injectors, pump, fuel pressure regulator, or even the MAF. I'm going to check the spark plugs to see if it's running too rich or lean and if all the plugs look the same. I wish I had a parts car at this point so I can start swapping parts to eliminate each component.

Thanks for any ideas or suggestions!

 

Do you have spark? Good, strong spark.

And injectors are pulsing?

By the way, it's an Air Flow Meter, not a Mass Air Flow sensor. They're different. No biggie though. Is your air filter clean, which could prevent the flapper/door in the AFM to not be moved?

When it died in the desert, how did it die? Sputtered and coughed out, or just flat stopped?

 

I do have spark but I'm not sure exactly how strong. I'm not sure if all the injectors are pulsing.. how would you check that? (maybe hold a long screw driver to each injector and feel for it at idle...?)
I knew I got that wrong because I was corrected in a different thread, they called it a Air Flow Vain Meter or something like that.

When it died I just noticed a rattle and 0 RPM (the rattle was like the noise of loose rockers in the top end). After I pulled off the road I tried starting it and got nothing. There was no sputter and zero detonation when attemping to start it till I unplugged the TPS and AFM. I tried tapping, removing, and swapping relays (everything went back the way it was). I tried unplugging and plugging back in the ECU. I tried unplugging the battery for a few minutes, I tried unplugging different sensors one at a time. I checked all fuses and even pulled the valve cover to make sure the timing chain was still in place. I checked the distributor, rotor, connectors, etc. I tried to hear for the fuel pump but couldn't hear anything when the key was turned on for a 3-5 second prime. (I'm guessing the fuel pump is in the tank).

Like I mentioned before it would run for about 3-5 seconds with the TPS and AFM unplugged (I tried just one of each but both unplugged together did the trick for a few seconds every time). I went to the bank to get money for the tow truck driver and tried starting it again after 30 minutes. It then would start up but run rough with the TPS and AFM unplugged and with the TPS and AFM plugged in (no difference). I now starts every time but has a rough idle with loss of power. I tried my spare TPS and it didn't make a difference. This is why I'm leaning toward the fuel system.

Thanks for helping!

 

I take it you have done the fuel pump jumper in the diagnostic connector? No change? You need to have someone turn the key off and on while you're under the tank with your ear close to it. You should be able to hear it buzz at least.

As far as checking injectors, a noid light is the proper way to test them. It's a very low impedance( I think that's the correct terminology) bulb that will flash when the injector is supposed to pulse. You unplug the injector and plug the noid light into the injector connector. If this isn't available, you may be able to feel them pulse/click with your fingers touching the side of the injector itself.

Have you examined each spark plug yet?

 

I just checked all the spark plugs and I have drastically narrowed down my search when I pulled #4 and found this....




I panicked for a second and did a quick compression test on #4 and it tested the same as before my trip when the engine had only a few miles on it (135psi at 6,400 feet and the pressure holds good).

Now my question is.. What caused this?? A quick Google search points toward severe detonation. So in my situation.. what could have caused this and will it happen again?
I also find it strange that the engine wouldn't start once this happened.. is it the knock sensor doing its job?

Thanks for helping me through this.

 

I would tend to think as you did, that something hit it.... I don't see how severe detonation could cause this. Detonation is just a premature explosion. I gotta wrap my brain around this...

Since it starts every time now, and you can regap the plug, does it run fine?

 

This is still a mystery to me. It makes snese that something physically hit it but it would have come out the exhaust valve without causing any noticeable damage??

I plan on replacing the plug tomorrow. I don't hear any odd noises but the rattle type noise I heard when it died now makes more sense. I'm going to check compression on the rest of the cylinders now.

 

Oh I woulda cleaned that plug, regapped it just to see if its was all good... Lol

I don't know if something could have hit it and exited through the exhaust. Anything is possible, and I see that the ground electrode is shiny in a few spots... But the question is: what hit it and where did it come from....

Let us know what you find.

 

The compression reading is 150psi on 1,2,3 and 130psi on 4 (all hold pressure good). I re-gapped #4 and put all the plugs in.. it runs smooth and sounds good.

I've been texting my fiance's dad and he says that it had to be debris and it could have come from the AFM (aluminum flap).

But the big mystery is what caused the engine to die completely and not start again??

 

AFM bound up somehow? Have you examined the AFM? I would inspect all hoses, air filter, everything. Gotta be an explanation....

 

The AFM looks fine but the inside of the intake looks pretty bad...


I think one of these carbon chunks got sucked into #4. :-/

 

Sounds highly logical. Time to remove and preferably have everything hot tanked. Or at least scrape and carb cleaner. If it were mine, and I had the time/money, the head would be coming off as well. Unless I removed the upper and lower plenum and could examine the intake valves to ensure there wasn't a massive carbon build-up in there. Then I would just do the upper and lower intake manifolds.

 

I have a spare upper and lower plenum and plan on replacing both before putting her back on the road. The head and engine is new so I'll leave it alone for now.

Still stumped on why it shut down and wouldn't start for hours...

 

We don't ask questions when things work fine... Lol

 

You're right.. I shouldn't push my luck.
Thanks for all your help!

 

Good luck, be sure to post pics of what you find in there!

 

After talking to my machine shop I decided to pull the top end as well as have the upper and lower plenum cleaned. I hope the cylinder walls, piston, and rings are still okay. They think the valve and or valve seat could be damaged slightly. I'd rather be safe than sorry.. especially with a new engine. I plan on updating this thread with more details and pictures.