intermittent misfire cylinder 1 code

There was a long running story with a Prius missing on cylinder one, turned out to be the injector after much work.

 

Search "misfire cylinder one during warm up".

 

The leak down test is performed the same as on any car. Just turn the crankshaft pulley center bolt with a socket wrench to position each cylinder to TDC, one at a time.

The compression test would require the Toyota diagnostic laptop to get MG1 to spin the engine.

 

You said you did the easy stuff already which included swapping the injector and the spark igniters (btw, why do we call them "spark igniters" here but they are 'ignition coils' every where else?) but did you change the spark plugs?

I also remember reading about leaking intake manifolds causing misfire DTC's and thats why you need to rule that out too.

 

The Toyota repair manual calls those parts "ignition coils". So you can use either name.

 

Ive never heard them called "spark igniters" until I came to PC but we are a unique group of people so I accepted it for what it was

I reserve the right to call them ignition coils at my discretion and take pride that even the Toyota repair manual disagrees with the PriusChat forum vernacular!

 

I have a 2008 Prius and have had a long running problem with P301 code. It has been to an independent mechanic and the Toyota dealership. Plugs, coils, injectors, compression tests, it has all been done. Finally, Toyota dealership convinced me it was ECU and I parted with 936.00 dollars. Four weeks later, P301 is back! Toyota expert took pictures of diagnostic that was run and sent it somewhere. They said check injectors and do compression test. It has already had 2 compression tests and I don't know how many times injectors have been out. It would appear there is NO fix to this problem.

 

There’s no problem (in cars) that couldn’t be fixed (to as good as new). Unfortunately sometimes it’s not feasible, but still…

After plugs, coils, injectors, mechanical, and ECU are ruled out it pretty much has to be wiring. Unfortunately many shops seem to be rubbish at finding problems in wiring. Good shop should check the wiring carefully before going for ECU.

 

The injectors clogging up is a very common problem on hybrids since they stop firing on a hot engine quite often and create carbon deposits on the ends. Now you mentioned you changed plugs and swapped ignition coils but what exactly did you do with the actual injector? Was it changed and did you use a new OEM part?

I would also suggest to run a full can of Seafoam through 1/2 tank of gas then run a 2nd can in a full tank. That will eliminate water in the fuel and help to clean any injectors which might have issues with deposits as well.

 

it sounds like a grounding issue with your car, especially if it has been flooded and submerged. Make sure the engine and chassis grounds are not corroded. Find each one and unbolt, take a wire brush and clean the metal, there must be bare metal underneath. Smear a dab of dielectric grease and tighten. Also check the wiring harness for damage or shorts. Since newer cars use coil on plugs, the wiring loom leading up to the coil is low voltage and easy to repair.

 

Had the same misfire on cylinder 1 (P301) before and after ignition coil replacement, all 4 fuel injectors, and the EGR valve replaced (under enhanced service warranty from Toyota). $2,000 later the dealership suggested I just replace the entire engine with a salvage ($4,600) since the mileage is at 138,000. I notified Toyota of the situation and informed them that many people on the Prius Chat were experiencing the same issue. As suggested, I notified Toyota but there was nothing they could do since there are no warranties available given the mileage and no enhanced warranty because of a "known issue". I expressed DISAPPOINTMENT because I purchased a Toyota for their Quality reputation and expected it to last longer than American cars. I owned a Dodge Dynasty back in the day and it has 165,000 miles on it before having trouble with a rod.

 

Misfires are often engine damage especially misfires that continually move around from cyl to cyl caused by running the engine so low on oil it throws a check engine light or master caution triangle.
Running low on oil in this engine usually damages the piston wrist pin bearing causing slop of the piston in the bore that causes vibration in main bearing and that bottom end vibration distorts the cam and camshaft fg & pg waveforms and the engine ecu can not decode this and sees tht as loss of expected power and throws a misfire.
Seen hundreds of destrgoyed motors on this forum from very poor oil maintenance.
It’s such a reliable car people rarely open the hood apparently.

That’s unfortunate because if it’s a 100000+ mile motor it most likely eats oil so you consistently run the engine with very low oil if you do not regularly check it.

This situation is greatly exacerbated if you have the car oil change done at the dealer who use terrible oil and will never inform you that you rolled in with no oil in the crankcase. Do you never know you own an oil eating little monster.

If I had consistent misfires after much work I would put the car up on blocks and put the car in inspection mode and with the car Engine running continuously in inspection mode listen very carefully under the engine for vibration.

Engine damage starts with misfires. Then becomes knocking then if continued to drive the #2 piston likes to fly out the side of the block.

Seen that many many times here.

Check your oil every saturday before starting the car. More frequently if you notice any oil loss.
Keep the oil right at the full line,

 

I wouldn't jump to conclusions right away that engine misfire is always major mechanical issues unless you've already ruled out the simpler fixes already.

 

Who said always.

Not a conclusion but a possible cause.

 

What simpler fixes are you referring? I am still in line to have the engine replaced but can try some other options. Someone informed me that it could be a sensor or computer issue. I did notice the coolant reservoir running a little low. Can I purchase the 'pink' solution anywhere as long as it is pink (ie:Walmart)

Note: compression test was good and cylinder leak down test found traces of coolant in cylinder 1, most likely caused by head gasket leak - per dealer. They recommended tearing down the engine to confirm (sounds costly to me).

 

Also saw something about testing the EDC DME before replacing sensors+labor. Cost ~95.00