i have a misfire in my 89 toyota supra. i didn't list all the stats last time and i had several answers which didn't seem quite right. its a 7m-ge engine, non turbo, 3.0 liter inline 6. i believe one cylinder is misfiring and i know which one it is. i just want to know what might have caused this, what should be done to fix it, and how much that will cost. thanks
2006-10-08 19:43:00 · 4 answers · asked by b4dmuthafuka 2 in Cars & Transportation ➔ Maintenance & Repairs
Well if it is a true misfire and not a compression problem, then check that plug and replace it, replace the wire, if it is a distributor type ignition check inside of the distributor cap for damage to the prong that feed that cylinder. If it is a multicoil system (distributor-less system) check the coil that feeds that cylinder it may be bad, this would be unlikely though because they usually feed more than one cylinder and that would mean 2 cylinders misfiring. If this is all good you may have an internal problem like bent valves, blown rings hole in the piston from detonation of bad gas, water in the cylinder, or a cracked cylinder. All of these can resemble a misfire because although the cylinder is firing there is no compression, so the cylinder is still not supporting the engine, so it will run rough. If you have water in the cylinder, water is harder to compress and does not burn so this will also cause it to run rough.
I hope this will help you.
2006-10-08 19:58:46 · answer #1 · answered by Josh 2 · 0⤊ 0⤋
Well let me see. The following can cause this
#1 bad plug( can be ok at idle but break down under load
#2 bad wire.
#3 Bad coil. Some coils are a cap and coil all in one.
all of the above will be between 3 and 60 bucks. If you can buy just 1 wire, switch it to another spark plug and see if the miss changes. If it does it is a bad wire.
The bad thing is you can't buy 1 wire.
If it is the coil type wire attached to the spark plug it could cost 120-150
2006-10-09 02:50:13 · answer #2 · answered by goldwing127959 6 · 1⤊ 0⤋
Try swapping plugs, then wires with another cylinder. If that doesn't do it, perform a compression test. You may have a burned exhaust valve.
2006-10-09 03:45:37 · answer #3 · answered by Anonymous · 0⤊ 0⤋
mmmm..it could be as simple as a bad spark plug.or something as seriuos as a damaged valve in that cylinder port.(whitch would be a costly repair).
2006-10-09 02:48:14 · answer #4 · answered by swamp angel 3 · 0⤊ 0⤋