1992 3vz e engine misses and feels held back

snowjrmydc wrote:
> I recently replaced my spark plugs, fuel injectors, and catylitic
> converter. I also did a full tune up not too long ago. The engine
> continues to miss and feels like it is being held back under a light load.
> My gas milage has also dropped a lot. What could this be?
>
My guess: Mass Air Meter (MAS), or Throttle Position Sensor (TPS). Get
the specs from your Factory Service Manual (FSM), and ohm 'em out with
your multimeter.
Given the mechanical design (rheostats) of this generation, they will
fail eventually. And, OBDI error codes are not always definitive.
In my case, I had a failing MAS.

'89 4Rnr 3VZ-E 220K

(...you DID check for the notorious bad head gasket syndrome, right?
Exhaust CO/CO2/HC in coolant?)
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

i have replaced all the things you mentioned.
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

I presume you changed the oxygen sensor too. Al

snowjrmydc wrote:
> I recently replaced my spark plugs, fuel injectors, and catylitic
> converter. I also did a full tune up not too long ago. The engine
> continues to miss and feels like it is being held back under a light load.
> My gas milage has also dropped a lot. What could this be?
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

nope i have not done the O2 sensor
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

Scotty wrote:
> "snowjrmydc" wrote in message
>
>> I recently replaced my spark plugs, fuel injectors, and catylitic
>> converter. I also did a full tune up not too long ago. The engine
>> continues to miss and feels like it is being held back under a light load.
>> My gas milage has also dropped a lot. What could this be?
>>
>
> I had that issue and stuck a bottle of injector cleaner through it. Came
> good within 60miles. I dont use mine much (1,200miles a year) so poor fuel
> was my culprit, try that and see what happens.
>
> Also did you replace your fuel filter? Sparkplug leads good? Rotor and Dizzy
> Cap good (that was the first thing that went on mine), Coil output okay? Did
> you recheck yoru plug heat range and gaps? TPS playing up?
>
>
When I had this issue I cleaned my MAF and the truck drove like new
again... Literally. It was crazy!!!
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

The oxygen sensor could be the whole problem. If it gets sluggish the
engine will run rich and cause the symptoms you're experiencing. If
you have access to a scanner you can watch the behavior of the oxygen
sensor. It should change rapidly from about 200mv to about 800mv.
Hope it helps. Al
snowjrmydc wrotep
> nope i have not done the O2 sensor
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

How many miles are on the engine? Did you run a compression check to
see if you have a valve problem? On first compression you should be
reading around 80 psi and on subsequent compressions the pressure
should climb to around 175 psi. Another thing that causes these
symtoms is timing and the anti knock sensor wire.

snowjrmydc wrote:
> I recently replaced my spark plugs, fuel injectors, and catylitic
> converter. I also did a full tune up not too long ago. The engine
> continues to miss and feels like it is being held back under a light load.
> My gas milage has also dropped a lot. What could this be?
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

I have some of this trouble on a 95 and was trolling this newsgroup
hoping to find some info.

Besides being kind of anemic it idles TERRIBLE. Thats the real
complaint. It does have fresh plugs, dist cap and rotor.

The code that pops up is 26 for rich condition seen by o2 sensor. It has
also popped up with lean condition too. My idea was that the injectors
may be leaking, but I have no real basis for this. Cleaners have been
run in the tank hoping for improvement.

I'll peek at the MAS as Dante pointed out since that is one of the
troublespots my scanner pointed to.

Any other ideas appreciated.

Remember to take out the trash if you want to email me.

-SP

snowjrmydc wrote:
> I recently replaced my spark plugs, fuel injectors, and catylitic
> converter. I also did a full tune up not too long ago. The engine
> continues to miss and feels like it is being held back under a light load.
> My gas milage has also dropped a lot. What could this be?
>
 >> Stay informed about: 1992 3vz e engine misses and feels held back 

"Speedy Pete" wrote in message

>I have some of this trouble on a 95 and was trolling this newsgroup hoping
>to find some info.
>
> Besides being kind of anemic it idles TERRIBLE. Thats the real complaint.
> It does have fresh plugs, dist cap and rotor.
>
> Any other ideas appreciated.
>
> Remember to take out the trash if you want to email me.
>
> -SP
>
Speedy,
I had a '95 that I put 60k miles on and now have '00 Limited/SC'r with 65k
miles. About twice a year I buy 2 bottles of Techron FI cleaner at Wal-Mart
and run thru it. I run the 18 gal tank down to 1/4, add a bottle and 6 gals
of gas, then run that tank back down to 1/4, add the 2nd bottle and fill the
tank. Then I run that tank to almost empty. That gives me ~24 gals of gas
to 24 oz of Techron because my tank takes 12 gals to refill at 1/4 tank.
Since I have the SC'r I also have 2 step colder Iridium plugs with 40k miles
on them, and I have never had a problem with idleing. My W had a '86 PU. I
also used the Techron and never had a problem with it either.

Ron
 >> Stay informed about: 1992 3vz e engine misses and feels held back