P3191 - Bad Gas? Injectors? Coils? 289k Miles

I've had some non-ethanol gas stored for several years which I believed to be well-preserved by using "PRI-G COMPLETE GASOLINE TREATMENT". It still smelled right, but when I pumped out the first 5 gallons, I added some more "PRI-G", just to make sure. After putting that in my 2009 Prius, the fuel economy increased and it performed well, so I figured all was well with the fuel. However, when I pumped out the next 5 gal, I forgot to add the PRI-G. Also, it was from the bottom of a 55 gal steel drum. After I poured about 4 gal on top of probably 4 gal that was remaining in the tank, I drove it. After about 4 miles, I felt it shudder. I think it was trying to start the ICE. After it happed the 2nd-time the red triangle came on. I stopped and read the P3191 code. I turned around and headed for home, only powered by the HV battery for maybe a mile, when it stopped. My wife came with our pick up and we towed it home in neutral - about 3 miles.

Here is what I've tried, so far, while hoping the gas wasn't the problem:

I read a lot of posts on Prius Chat - grateful for so much helpful info .

Replaced spark plugs - old ones looked OK, but rust on top side of #4. I assume water leaked from the top, but wondering if there could be a head crack in that area? After replacing, the shuddering stopped when trying to start the ICE.

A few days prior, I replaced the secondary engine coolant pump - tardy for several months;

Replaced MAF after cleaning old one with CRC MAF cleaner, which didn't help. It wasn't previously replaced for at least 200K miles

Throttle body very dirty; I cleaned it well with CRC TB Cleaner.

After every change I've made, I tried to start the ICE. It sounded like it was running, but only for about 15 seconds. I read somewhere that it is near impossible to perceive the difference between attempted starting and actually running of the ICE. I also heard that the starting procedure lasts for 15 seconds. I'm keeping a trickle charge on the 12V battery with it disconnected, except while trying to start. I understand the starting is powered be the HV battery. I hope it doesn't go dead. I don't know how to charge it. I only do one test start for each change I make.

Air filter good; recent oil change(regular change/filter every 2500 mi); inverter coolant pump replaced a month ago.

PCV valve due to arrive tomorrow. I'm embarrassed to say I've never changed it -- didn't even know it had one. I did find it and will hopefully replace it tomorrow.

Questions:
* Would 1 ignition coil going bad cause this? I wouldn't think 2 would go bad at the same time.
* Same question for the fuel injectors... Maybe they got clogged by something in the gas, from the bottom of the drum?
* What(if anything) should I do about the fuel? I'm thinking about adding some PRI-G to the fuel tank, wash it down with some gas, and jump on the bumper to mix it in . Should I try to drain the gas? If so, how? What about the fuel in the line between the tank and the injectors?

I'm 66, have made most of my own automotive repairs all my life, but have no formal training, other than help from my Dad earlier in life, who was a HS teacher of auto mechanics. I don't have any specialized tools to troubleshoot this problem. I am technically minded, but in "over my head", with this problem. Thanks in advance for your thoughts on this...

 

Thank you for your comments, mr_guy_mann. I have some questions:

1. if my "HV battery is depleted", why does it still turn the ICE over for 15 seconds, every time I've tested it after making changes?
2. If I have stuck valves, would I hear some odd noises while the HV battery is trying to start the ICE? I haven't noticed that, so far.
3. The car ran a total of less than 100 miles on the stored gas and a small engine ran 2-3 hours on the same gas with no problem. Is less than 100 miles on the Prius enough to form "gummy deposits that can cause injectors and engine valves to stick."
4. I understand how this would cause the ICE to run rough, but is any of this enough to cause the ICE to fail to start?

I will look for a post about how to "pull and clean the injectors".

Thanks again for your interest in this problem

 

I'm also wondering if the ECU shut down the traction motor, after approx. 1 mile, to protect HV battery from depletion? That could explain why I am still able to use the HV battery to attempt to start the ICE. Is this logical? -Sid

 

It does help . Thank you.

While the ICE was attempting to start, I listened for the fuel pump, as you said. I heard the pump start a few seconds after the cranking started and it ended a few seconds after the cranking stopped. I would assume this to be normal, especially since I did the exhaust sniff test just prior, which would have left pressure in the fuel line. At the exhaust pipe, I did smell unburned fuel. It wasn't as strong as I thought it might be, but I did not smell anything like normal exhaust, so I don't think it was firing on any cylinders. Neither was there any shudder. It sounded like either a very smooth start or no firing at all. I assume the latter... I don't have a fuel pressure gauge...

Questions:

1. Should I still try to replace the fuel, even though it appears to be a no-spark problem? If so, do you have ideas about how to do that?
2. Should I try cleaning the injectors, in case I'm wrong about no-spark?
3. I'm still waiting for delivery of the PCV valve. Correct me if mistaken, but I wouldn't think a stuck PCV valve would be cause for a ignition failure, unless it has a sensor that tells the ECU to cut power to the coils.
4. Considering that the spark plugs are new and I don't understand how one bad ignition coil could cause this, What could cause a lack of power to the coils?

-Sid

 

The new PCV valve arrived and I installed it. The old one -- probably 200,000 miles on it -- looked fine and still rattled normally.

In some other threads, I saw that overfilling the oil could be a problem. I recently changed the oil/filter. My manual says to use 3.9 quarts of oil. I've always used 4, figuring that should be fine. However, on my dipstick, I saw it was about 1/2" above the full line. So, I let out about 1/4(guessing) quart. Now it is about 1/8" above the fill line. I'll drop back to 3.5 quarts in the future.

After all this, I disconnection the 12V battery for over 30 mins, reconnected, then tried to start it. No change. It cranked for about 15 seconds then stopped. I hope the HV battery will hold up long enough to get this solved...

 

When I changed the plugs and saw this, I assumed water somehow leaked in from the top. But now, I think I have a bad head gasket, at the least. Here's why:

1. The seal on the coil pack seems to be in very good condition.
2. The discoloration I can imagine could be dried Toyota coolant. Similar colors were on the bottom of the coil pack tube.
3. I've had to add a little engine coolant twice to get it to the top of the reservoir.
4. When I checked the dipstick, the oil was about 1/2" inch above the full mark after I recently changed the oil - 4 qts. My manual says 3.9. That's what I've always done.
5. Since there was too much, I let some oil out of the drain. I'm guessing about .25 quart. Then it was about 1/8" above the full mark.
6. The oil I drained out didn't look right - not like the new oil that I recently filled it with - more of a tan color. I've seen that before on other cars when there was coolant in the oil. I checked the bottom of the oil filler cap, but it seemed fine.

I don't know what other problems my Prius may have, but I'm pretty sure the head gasket is leaking or the head is cracked. What do you think? Since it has nearly 290k miles on it, it may be time to "call the undertaker...". Can you think of any reason(s) I should try to save it?

 

I'm pretty sure the gas in the barrel hasn't gone bad and the barrel is clean with no rust... but water...!! I hadn't thought of that! It is possible some rain water may have entered the air vent in the barrel also. That would explain why it ran well on the first 5 gallons I put in the tank. Thank you!

I have a trailer that I think I can get the Prius onto so I can take it to the dealer with my pickup.

I may have a leaky head gasket also, but that must have pre-dated this problem and I wouldn't think it would prevent starting... but water sure could. That could also explain why I'm pretty sure I'm not getting fire in any of the cylinders... That may also explain why the only code I'm getting is P3191 - no start. That may also explain why I only got a slight smell of un-burned gas while sniffing the tail pipe during cranking. Water... I should have thought of that...

 

Thanks! I'm on it... found instructions here: DiY Grid Charger | PriusChat

 

I ordered the LED power supply and also the 72W 12V 6A PS for running the fan last night. I'm expecting it tomorrow. Then it occurred to me that I probably don't need the 12V PS. I could use any 12V battery, keeping it charged with a regular car battery charger. Or, I could use a house fan on grid power. I see you didn't see a need for the fan and it seems to be OK?

The switch seems like a good idea. I assume that's on the output of the LED PS? It seems to me that if that switch is turned off before unplugging the power to the LED PS, there should be no need for the diode and resistor. Is that what you where thinking?

Are you monitoring voltage and amperage? How is it helpful to do so?

 

Thank you for this info...

The 4-year-old gas was still good because of PRI-G, which claims to last 5 years. However, I had only about 10 gallons of gas in a 55-gallon drum, which was vented. With all the expansion/contractions with large temperature changes, causing a lot of air-exchange, I'm pretty sure a lot of water condensation happened. I failed to understand this when I pumped gas from this drum into my 2009 Prius. That's what caused the problem.

This is how I removed the gas: How to manually power in-tank fuel pump - Gen 2 Prius | PriusChat . Before pumping it out, I added HEET(methane), HEET(iso...), PRI-G, injector cleaner and filled the tank with good gas. I disconnected the fuel line behind the engine and connected a 5/16" fuel line to a container and pumped all the gas out. Then I added a couple gallons of 91 octane gas(10% ethanol) and pumped that out also. Then I added more of the 91... Then I reconnected the fuel line and loosened the fuel rail, disconnecting the injectors, and turned the pump on to flush that out. After all of this the ICE started immediately after I powered it on.

It ran very rough - missing on #2. Compression testing with and without added oil indicated the rings are bad in 2. The other 3 are much better - reasonable for 290k miles. Restore's "Engine Restorer" has good reviews on youtube and excellent reviews on Amazon. So I added that to the oil, after draining enough oil to make room... That seems to be helping, but need to drive it a lot more to see... I put a new coil on #2, but don't think that changed anything. I cleaned the injectors and replaced #2. That helped a lot. I will soon replace the other 3. I'm thinking the water wasn't good for injectors... The ICE is running almost normal now with only seldom error codes. I am grateful .

Thanks for mentioning the "grid charger". I got much helpful info from this thread: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat which helped me make this: Grid Charger | PriusChat . That really helped me get through all the troubleshooting of the P3191.