Rough idle and voltage change

[Coopsdaddy]

About 1 'month ago my 2000 limited with 120000 miles started rough ,then I took off and it thru a cel.Scan gauge read 300/305,so I decided to change plugs and wires with one parts.I also swapped #1&5 could pack around to see if that might be it.It seemed a little better but still did it once or twice but no cel.Than 3 days ago it wouldn't start,battery was 5 years old,so I put it a new battery.My volts have always read 14.1,now it reads 14.1 down to 13.7,it never did that before?It only has the low rough idle after it has been ran,shut off for a little bit than restarted,never after leaving overnight yet?
Any help would be appreciated!

 

[JayRolla]

About 1 'month ago my 2000 limited with 120000 miles started rough ,then I took off and it thru a cel.Scan gauge read 300/305,so I decided to change plugs and wires with one parts.I also swapped #1&5 could pack around to see if that might be it.It seemed a little better but still did it once or twice but no cel.Than 3 days ago it wouldn't start,battery was 5 years old,so I put it a new battery.My volts have always read 14.1,now it reads 14.1 down to 13.7,it never did that before?It only has the low rough idle after it has been ran,shut off for a little bit than restarted,never after leaving overnight yet?
Any help would be appreciated!

That voltage is fine. 13.7v will charge battery with no issues. What type of plugs and where used?

 

[Coopsdaddy]

Ngk plugs and ngk wires

 

[Coopsdaddy]

Btt?

 

[amalik]

That voltage is fine. 13.7v will charge battery with no issues. What type of plugs and where used?

Wouldn't you say it's odd though for a *new* battery to report at 13.7V when his old one was 14.1v?

OP, how long did you monitor the old battery at 14.1V, a number of weeks and months or was it just a one off?

 

[ThorInc]

I am with the JayRolla, from what you have described, no issue. What was the old battery and what's the new one?

 

[gamefreakgc]

Have a history of bad gas in the tank? Might be a fuel delivery issue or a clogged filter. A total guess though. Oh and check your air filter, if it's clogged up the engine will idle funny.

 

[Coopsdaddy]

Still happening,it will start up rough and sometimes the cel will come on,showing a 305 code,then it clears ups and a little bit.
Don't no if it has any thing to do with it or not but I didn't notice the voltage change much before the new battery,it runs down the highway at 14.1yhan drops as low as 13.4-13.5 sitting in park,rpm in park is 690-710

 

[Coopsdaddy]

I swapped coil pack around and it still says 5 cyl,can a injector act up like this,or do they just go out?

 

[TheDurk]

Still happening,it will start up rough and sometimes the cel will come on,showing a 305 code,then it clears ups and a little bit.
Don't no if it has any thing to do with it or not but I didn't notice the voltage change much before the new battery,it runs down the highway at 14.1yhan drops as low as 13.4-13.5 sitting in park,rpm in park is 690-710

Perfectly normal. Spec is 13.5-14.5 with engine running AT THE BATTERY. Guessing your using a ScanGauge or similar. That will tend to be a tad lower, because it's behind fuses and some fine gauge wiring.

The lower voltage with a newer battery is also not a surprise. A dying battery has relatively little capacity to absorb a charge. If I put a battery on a charger that has had even a little use since last charge, and it only sucks 2 amps, I figure it's not long for this world. Should be able to pull as much as the charger or alt. can kick out when new. When it does, the greater amp draw will lower the voltage reading a tad. I bet that's what you're seeing. Newer batt sucking more amps.

I know more about electrics than I do about injectors; this is my first FI machine. (I have worked on others since got this in '99.) But yes, they can fail in all sorts of strange ways. It's still not definitive, you could have a valve issue, for example. But I doubt your issue is a new battery.

 

[Buckaroo]

Good thought about the injector as you are looking for something cylinder specific and yes, they can go in and out. You can check resistance on the injector coil and swap it to verify the problem.

Buckaroo

 

[Toyotayoda]

swap coil and spark plug with another cylinder, if the misfire stays in the same spot you can swap injectors, luckily your dealing with the passenger side of the engine and don't have to remove the intake. If the misfire moves you likely have a bad coil, if the misfire stays check compression. Compression check is only to confirm you need an injector, no one wants to buy parts unnecessarily. Altrom is the OE manufacturer of the fuel injectors.

 

[Coopsdaddy]

I swapped the coil pack,it looks to be good,so maybe time for a compression test,what numbers am I looking for and do I need to take all plugs out during test or leave them in ?

 

[Coopsdaddy]

I'm going to go ahead and change # 5 injector,I can get one oem for 28 dollars or all six for 106 dollars off eBay,I wouldn't change all 6 but should I change the three on passanger side or just the #5?
They come with orings so it looks like I just need maybe banjo washers for the fuel rail?
Is the oem aisin?
Looks like I need o rings,fuel rail washers and vasoline?

 

[Coopsdaddy]

Are these oem
Aisin brand