Switch Gas From 91octane To 89octane

[choppacity305]

ok i have a 93 es 300 i was putting 91octane premium gas in my car then made a mistake put 89octane plus and car hasnt been the same since.i noticed knocking/pinging from the engine,loss of acceleration, the heavy vibrating while i drive and lots of smoke from my exhaust pipe which smells like a loud smell of carbon gas.also the car shuts off if its when i stop and im not moving for like 5mins.this has become a real pain in the !Removed! and i need suggestions on how to get my car back to its best performance running again so please guys can u help me with your expertise?

[branshew]

On rare accosions I would put 89 Octane in my '95 ES (like when the station was out of 93 octane) and I never experienced the problems that you describe. I don't think that it's necessarily related to the gas.

Could be a couple of things:

Sounds like a possible clogged injector. I would fill up 1/2 tank w/ 91 or 93 Octane if possible. Run a full bottle of Techron or other high quality fuel system cleaner through the car in the 1/2 tank of gas. That may help, but chances are you're going to need to have your injectors cleaned.

Alternately you could have fouled plugs. When was the last time you had the plugs replaced? What color is the smoke coming from the pipe?

[amf1932]

It probably was just a coincidence that caused your car to react in this way. This slight change in the octane rating wouldn't cause it. Even if you changed back to 91 or 93 I think this problem will continue.

I agree what branshew said in the above post.

[Toysrme]

Ok, in the first place, you have a 3vz-fe. You have no reason to be running 91 octane. It will give you lower mileage, and lower performance as the engine was not designed to run with anything more than low octane gas. (Which in itself is a joke because they were further de-tuned in 92-93 to reduce performance).

Changing the octane had nothing to do with anything, you just have bad luck!

First... Check for vacuum leaks. Disconnected / broken hoses. The main culprit is always he hose that runs from the throttlebody to the Air-Flow Meter.

If you check for vacuum leaks and swear you can't find any broke / split / disconnected hoses, check spark as you many have dropped a few cylinders. (The v6's are proven to run OK on 5). Replace the plugs with NGK, or Denso models & check the wires (DO NOT replace the wires with some cheap *BLEEP* from a store. Either spend the $100-110 for OEM wires, $120 for Vitek wires, or $250 for magnacore if your current wires are broken. Everything else is crap & will last a few months, then break.) If you got $15 to spend, go a head & replace the rotor & distributor cap.

If it's not immediately better you probably burned up the cat with all the unburnt fuel through it.

On the other hand, if you're getting clouds of white smoke you blew a head gasket.

If you think it's a bad injector it is easily enough tested (But you gotta take the upper intake air chamber off -> no big deal)

1) Hook up a fuel pressure gauge

2) Disconnect all fuel injector harnesses but one -> Including the cold-start injector (So only one injector fires at a time)

3) Disconnect the wire between the ignition coil & Distibutor cap so there is no ignition

4) Turn the engine over

By watching the drop in pressure across the injectors one at a time -> You can see which injector may be having a problem.

I wouldn't run fuel injector cleaner through there for three reasons.

1) It's just so rare a Denso fuel injector is clogged in the first place & I think you have the exact opposite problem. -> Unburnt gas, not running lean.

2) If the cat is shot, it's going to be even worse when some cleaner is shooting in it.

3) Don't succumb to a "fuel injector" cleaning service either. To clean injectors they get taken out, taken off the car & either fully disassembled, or dunked into one of the sonic cleaning tanks -> then disassembled.

Dealers will tell you they can do this, when in reality they just dump whatever generic fuel injector cleaner that's hella cheap into your gas tank.

[choppacity305]

yeah guys your right it has nothing to do with me changing my gas just bad coincedence i guess.i went to see a mechanic and got my engine diagnostic test it seems that i need 2 knock sensors,gaskets,and some vacuum hoses are loose so that may be the problem thats causing smoke from my exhaust.The knock sensors are expensive though cost about $158 a piece plus with labor cost they quoted me to fix is about $500-$600 dollars.To me it seems like good deal what do u guys think? Thanks alot for the replies guys u were very helpful.

[Toysrme]

I think you're in danger of getting screwed. (As in you are getting screwed)

Any honest mechanic is going to realize the vacuum leak is going to cause your main problem (stalling) & if there is a knock sensor CEL - it's going to be due to the engine knocking out of spec.

The correct way is to fix the vacuum leak, reset the ecu (Pull the EFI fuse a second & replace it) THEN see if you have any problems left.

& you never said anything about a check engine light being on... Was your check engine light on? If not - you don't need knock sensors.

I think you're paying for at most a $70-100 part & getting robbed for 600.

[choppacity305]

yeah my check engine light is on also and i had my car check by two mechanics and they both said the same thing i need to replace the knock sensors,gaskets, and vacuum hoses are loose that could be causing the problem.

[cardona6569]

yeah my check engine light is on also and i had my car check by two mechanics and they both said the same thing i need to replace the knock sensors,gaskets, and vacuum hoses are loose that could be causing the problem.

←

Hi: First things first, fix the vacuum problems/loose lines, that should be cheap. Then if that does not fix it then do the sensors. If you go to the dealer, youll see their location and maybe you can change them yourself with little problems.

C. PR

[choppacity305]

hey guys can u believe after getting my knock sensors, gaskets with harness replaced my car is still not working because it has loss of power.i mean after pressing on the gas my car goes nowhere the mechanic says this is due to my car burning oil and gas mixed together which is causing smoke from my exhaust pipe which smells like carbon monoxide.they tell me they cant fix it and suggest i go the junkyard find a new engine or get a new car.this is some bull*BLEEP* $361 dollars down the drain for the parts and my car still isnt fixed there has to be another way too much money has been put into my car now.guys i need major help is there a chance my car can be repaired without being screwed again please help?

[chuckb]

that sucks, good luck.

btw-how many miles?

[monarch]

suggest i go the junkyard find a new engine or get a new car.this is some bull*BLEEP* $361 dollars down the drain for the parts and my car still isnt fixed there has to be another way too much money has been put into my car now.guys i need major help is there a chance my car can be repaired without being screwed again please help?

←

No it's not likely your car can be fixed without spending thousands of dollars. In May you made a decision to buy a luxury car with 150,000 miles and no preventive service records. Such cars commonly have severe mechanical wear and tear and are on their last legs. Your car, for example, overheated just two months after you got it and then you kept on driving with the temperature gauge ABOVE the red zone which is like pounding nails into the coffin of an already worn and neglected car. More recently you've been driving around with the motor "knocking/pinging from the engine, heavy vibrating and lots of smoke from my exhaust" which is like which is like pounding even more nails into the coffin.

At this point I think you have 3 choices:

1. Spend thousands of dollars to have a good used engine installed + all new emission system componets which were likely burned up by the overheating / pinging etc. This would probably be a mistake since your transmission and other mechanical parts of the car are likely worn too due to years of preventive maintenance neglect and would soon need to be replaced as well.

2. Install new spark plugs to try and get the motor to run half decently so that you can try and sell it to another young buyer who, like you, was willing to buy a luxury car with 150,000 miles and no preventive service records.

3. Part out the car or sell it as is in non-running condition.

[Toysrme]

Get a compression check, or a leak-down test done to see if you have a blown head gasket.

If a HG is shot, either buy a used JDM 3vz-fe off ebay to drop in it (If you have emotions you'll need to swap the EGr system over - no big deal).

Or rebuild it.

Check that the block & heads are flat (Machinists level & feeler gauges. No more than 0.003" from side to side in straight, and crossways.

If they're not, go to a machinist. Head repair services normally only run $50-75 a head.

When you buy new head gaskets. Victor Nitroseals - graphite/steel (Napa/Car Quest) are the strongest available without custom multi-layer steel, or copper head gaskets.