Last night the car started feeling like it was running on 7 cylinders so I pulled codes and it said #3 was very weak but not dead. I hooked up a timing light, and the wire was firing and everything, so could this be a fuel injector problem instead of a plug/wire problem? Before I go changing injectors, would fuel injector cleaner help at all? Thanks.
Cylinder 3 very week
- Thread starter jpctln
- Start date
Pull the plug first and swap in a fresh one. Grab a noid light at the parts store, if you dont have one.
Both of these, along with a compression test on that cylinder (done while swapping the plug for convenience), can help narrow it down.
Good luck.
Both of these, along with a compression test on that cylinder (done while swapping the plug for convenience), can help narrow it down.
Good luck.
Black1987Stang
Active Member
Do a compression test, then add some oil in the cylinder and redo the compression test. If the results become higher your rings are worn, i doubt this though since ive never heard one piston just lose compression one day. Another good trick is to put the piston at top dead center (on compression stroke) or bottom dead center i forget which one but hook up an air line to the cylinder (ur compression tester might have the fitting for this) and pump it up with a pump or just turn on the shop air and if air is coming out the intake then ur intake valve is leaking and if air is leaking out of ur exhaust then ur exhaust valve is leaking. It sounds like a spark or fuel injector problem to me. You can run ur car at night (hood up and idling)to see if that wire has a crack somewhere or if it is arcing off something metal. Also heard u can spray a light mist of water around the wires to see if a spark jumps from the wires. and check the injector with a noid light to see if its firing like Hissin said.
TrophyHead
15 Year Member
Black1987Stang
Active Member
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