My car has an irritating misfire when I'm cruising at a constant speed and also under very light acceleration, but when I am pushing hard on the accelerator it won't misfire at all, and it has no noticable misfire at idle either. The car is stock with the exception of full turbo back exhaust (no cats) and a cone style air filter. I don't want to go replacing shit if it won't do any good, also can someone tell me how to check codes, I did a search for it but didn't come up with any helpful results, thanks.
car misfires under light acceleration
- Thread starter TurboSupra7
- Start date
I had the same problem. Ended up one coil pack was bad. You can check the coil packs with a multimeter for voltage and resistance.
You can check your spark plugs to see if they are still good and also the gaps. How old are your spark plug wires? Is the ground to the coil pack assembly OK? That ground wire gets old and cracks easy with time, especially with many spark plug changes. It is easy to forget it is there and end up pulling it.
Can you check your O2 sensor? There is a diagram or flowchart of steps in the TSRM online.
How is your air/fuel ratio?
You can check your spark plugs to see if they are still good and also the gaps. How old are your spark plug wires? Is the ground to the coil pack assembly OK? That ground wire gets old and cracks easy with time, especially with many spark plug changes. It is easy to forget it is there and end up pulling it.
Can you check your O2 sensor? There is a diagram or flowchart of steps in the TSRM online.
How is your air/fuel ratio?
OK, Since you mentioned Coil Pack Ground wire, Where is this thing located. I can unscrew the Bolt and Pull my coil packs right off. Dont see a Ground wire anywhere.
Mine Backfires and Sputters at Idle and Under a Load. Working on this Problem for 2 weeks now.
Robert
Mine Backfires and Sputters at Idle and Under a Load. Working on this Problem for 2 weeks now.
Robert
Exactly.
You should not be able to just pull it right off like that. It is a wire about 6 inches long. It goes from the base coil pack foundation where the 3 coil packs seat onto. On this foundation is a screw (use a philips screwdriver) and the wire is attached on there with an eye ring (a small circle that wraps around the screw).
The wire goes to the head. There is a bolt that attaches the ground wire on that end (same explanation as the above but it is a bolt instead of a screw).
You can order this ground wire new from Toyota for around $10 or just make one yourself/get it from a parts store/etc.
Would this cause any of the Symptoms that we are having. I know for a fact that mine isnt grounded. I took atll the 10mm bolts off, Unpluged the coil lines and just picked the entire coil Assembly up.
Robert
Robert
supraguy31 said:
Yes, it will. My ground wasn't connected when I bought my car. I noticed it the first time I looked at it, so I took screw driver when I went to pick it up. I pointed out the miss to the previous owner & he knocked off $700. :boink: Gotta love it.
Yes, that ground wire is very important. For $10 go to Toyota and order it or make one yourself. Pretty easy to do. I described it in detail above. A 6 inch wire with 2 eye holes, one on each end. One end a screw goes in - the other a bolt...
This is the stock setup - as long as it is connected from that post where all 3 coil packs sit and connect it to the engine so you have ground you should be fine.
A misfire can also be caused by incorrect ignition timing, but that goes without saying as the manual lists that as a solution for a lot of different issues.
This is the stock setup - as long as it is connected from that post where all 3 coil packs sit and connect it to the engine so you have ground you should be fine.
A misfire can also be caused by incorrect ignition timing, but that goes without saying as the manual lists that as a solution for a lot of different issues.
Thnks for the Info on the Wire, I went out today and looked at my car. Ofcourse it wasnt there so I grounded it. Now I dont that the Timing Issue where the Timing mark is Jumping around. I still have the Sputter and the Poping sound through the Exhaust though. I problem Down, 2 more Problems to go. When I press the gas, My Check Engine light comes right on.
Code 11 is all Im getting but from reading the Manual, It says that no other code will you see with a Code 11.
What could all this be... The Saga Continues
Robert
Code 11 is all Im getting but from reading the Manual, It says that no other code will you see with a Code 11.
What could all this be... The Saga Continues
Robert
thanks for the replies everybody. I'll have to check that ground wire out, my only doubts about that are, if the ground were bad wouldn't the misfire continue whether or not I'm accelerating hard, because it only misfires at cruise or very light acceleration, no misfire at idle and no misfire under hard acceleration (at least not a noticeable one)
Thanks guys
-Nathan-
Thanks guys
-Nathan-
I have had much trouble trying to get my car not to misfire or die after acceleration. The dying after acceleration was caused by my ISC valve being filthy.
The misfire problem is a tough one and can be caused by:
1- Improper air/fuel ratio (running too rich for example)
2- Improper fuel pressure
3- Bad coil pack(s)
4- Bad or missing coil pack ground wire
5- Bad spark plug(s)
6- Bad spark plug wire(s)
7- Improperly gapped spark plugs or improper seating of the spark plug wires
8- Spark plug wire (and therefore the spark plug number) not connected to the correct coil pack (firing order)
9- Ignitor
10- Improper timing
11- EGR system
12- Vacuum leak
There is so much to check for a misfire problem. Some can be checked off based on the symptoms but these are the general ones.
The misfire problem is a tough one and can be caused by:
1- Improper air/fuel ratio (running too rich for example)
2- Improper fuel pressure
3- Bad coil pack(s)
4- Bad or missing coil pack ground wire
5- Bad spark plug(s)
6- Bad spark plug wire(s)
7- Improperly gapped spark plugs or improper seating of the spark plug wires
8- Spark plug wire (and therefore the spark plug number) not connected to the correct coil pack (firing order)
9- Ignitor
10- Improper timing
11- EGR system
12- Vacuum leak
There is so much to check for a misfire problem. Some can be checked off based on the symptoms but these are the general ones.