Engine misfire Code now what? What else to try? Bad idle at start up/cold

[lexicon]

Hi all
Vibe 2006
140k miles , this was a engine swap a couple of years ago. Judging from what I see, it was a haphazard swap... bolts missing etc etc

The idling problem started after the car died on her and the mechanic told her she needed a new battery, she says the alternator tested OK....after that, the problems began and error codes were thrown.....

Code lights went away on their own after installation of the new Igniter (which was just done ) and same error code came up the next day.
The car idles poorly at start up when cold and am told that the car idles OK after the engine is warmed up.
I have just asked owner to slowly increase idle speed when engine is warmed up to see if it increases RPM smoothly without misfire or stumbling
The most obvious items above have been addressed.


Am getting PO304 , cylinder misfire
-All 4 plugs have been replaced (by her mechanic)
- I installed a New OEM Denso igniter
-strong fuel injector cleaner has just been added to a tank ( not enough miles on the tank of gas to clean injectors yet)
-MAF was cleaned w the appropriate spray MAF solvent (by owner)
-cleaned throttle body valve

I don't have access to the vehicle , only when the owner has time to come over......
I just found out there is NO IAC valve on Toyotas w Drive by Wire..... (I edited this part of the post )

what else can be tried ?

[andrewclaus]

Don't rule out a mechanical problem. It's easy enough to do an engine compression or bleed-down test on this engine.

[joatmon]

could it be a leaky intake manifold gasket?

[lexicon]

joatman, are you saying that there could be a vacuum leak at #4 cylinder position? If cold, gasket is contracted, when warm it expands enough to seal and idles well afterward ? Would this generate a code ? PO304

[joatmon]

could be possible I suppose. Factory intake manifold gaskets have been an issue for a number of folks here. Don't know how to test it without just replacing it though, maybe some sort of smoke or ether thing. As hard as it is for you since the car isn't there much, even harder for us on this end of the interweb tube, but whoever owns the car is lucky to have you as a resource

[lexicon]

Thanks for the positive comment.
I was thinking of picking up a BlueDriver Pro OBD2 code/Engine reader.
There must be some scan that will pick up a vacuum leak ?

[lexicon]

Picked up a Bluedriver reader / scan tool.
Compared all the readings vs my own Vibe to her Vibe and there does not seem to be any parameters that are out of line in terms of MAP sensor, or Fuel trim readings etc
I will check the intake manifold gasket this week.
This all started when the battery died and was replaced....also, in the past there has been wiring damage due to rats attempting to nest in the engine compartment.....its too coincidental that the battery got changed and then all of a sudden, cold start idle was this bad

[lexicon]

The saga continues.... BluDriver code reader indicated a system misfire, and misfire on cylinder 3 and 4.
The day before the code indicator light came on the dash the serpentine belt broke and driver says she coasted to a stop but the temp gauge went to the top.......
Well, plugs were changed, the igniters were replaced , the old codes were deleted and there were no codes for several days. The idle was reset and the engine seems to run well and idles pretty good now......but
The coolant level was low and we added coolant....the next day, the radiator had a coolant gap in it and so there is no hermetically sealed coolant system....... two days later the code for engine misfire came back.
The engine idled fine and seemed to run fine, engine parameters read normal.

There were bubbles coming from the radiator when the cap was removed and run until the engine temperature came to normal. A blown gasket detection kit was purchased and it points to a blown head gasket.
So far, no coolant in oil, no plumes of white smoke, idle is pretty steady.....
Now we need to contend w the blown gasket.....
Option one, replace engine w 180k miles on it, replace gasket (about as expensive as getting a used engine w labor) or try Bars HG1 Blown Gasket liquid to give it a try and buy some time to see if a decent used engine can be found....by the way, can you used a same year Corolla or Matrix engine in a VIbe? its a 1.8 L engine.....

[lexicon]

Update:
The original misfire was a head gasket (HG) leak.
There were bubbles in the radiator as the engine warmed up and cap was left off to observe bubbles.
Coolant color change kit was used and confirmed that it was a HG leak.
The owner wanted to try Bars HG-1 Head gasket leak sealant.
Instructions on the bottle were followed. The bubbles stopped after the first heat/cold cycle. The car was slowly driven for 10 min and then cooled down two times after the first hot/cold cycle.
Its been 3 weeks. The owner reports there is no abnormal change in coolant volume .
So, for now, the leak appears to be sealed. This may hold weeks, months or years.
If the situation changes, this thread will be updated.

Bottom line, the owner indicates she shut down the car within a few minutes of the car overheating when the serpentine belt took out the alternator and power steering function. The head gasket should not have leaked , however when I first checked the coolant the coolant was clear.(not pink or green)..... so my assumption is that water has been added to this radiator for much longer than just once and regular maintenance may not have been followed for quite a while.
So, if you start with a misfire as a diagnosis, it may not point to the most obvious solutions , like plugs or igniters .......

[joatmon]

not optimal, but good to have it diagnosed and at least temporarily resolved

I remember the first time I heard someone talk about adding Bars Leaks to stop a radiator leak, I misheard them and thought they were saying they added barley to the radiator, thought this is some MacGuyver thing I wouldn't do to an engine.