cyl 4 missfire
cyl 4 missfire hey guys i just got a code for cyl 4 misfire..i need to fix this asap. does anybody know the resistance that the coil is suppose to have and also the resistance for the injector. i tried using the search but couldnt find anything. i think its either the coil or injector, maybe there is a piece of dirt stuck in the injector or something. Im not sure but could someobdy help me with those specs and whatever else you think it could be, i changed my plugs and wires last month but the i could also use the resistanc ein the plug wire to if anybody knows. i also need to know how to ohm test the coil..not to sure. thanks
hey guys what is the best way to clean the injectors while they are out...would it be safe to soak them in carb clean for a while or would it mess up the coils inside? thanks
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From: Schiller Park, ILL Member: #317
Not sure on the typical coil pack ohms, but the injector should be about 12.5 ohms.
Wires will vary depending on brand. The MSDs will be about 20-30 ohms, while the stock wires are more like 300-350 ohms.
Wires will vary depending on brand. The MSDs will be about 20-30 ohms, while the stock wires are more like 300-350 ohms.
Teching In
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I would avoid soaking your injectors but spraying some carb cleaner shouldnt hurt them. I had this problem on mine just a different cylinder and it turned out to be a clogged injector. Have fun with fuel rail removal...
i am removing the fuel rail right now and i have everything disconnect and im tryin to use the disconnect tool but its still be a pain in the butt. any advice here, i freakin hate these disconnect tools ive never had great luck with em. i probably suck at using them too.
Teching In
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Push the fuel line toward the motor and slide the tool toward the fuel line use all the colorful words you know and rotate the tool and continue to push and pull the fuel line until it disconnects, beer break is what it took for me to get it done.
alright got her off, now i noticed one of the plastic discs right under the o ring is broke on a different injector(only about a third of it is broke), is it going to leak now or will it be fine?
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Have you thought about swapping coils first. They are much easier to swap than injectors. Yeah the quick disconnect on the fuel rails can be a bit*h some times. Once you get it out you can spay it with carb cleaner if wanted. putting 12V on it will energize it if you want to pop it a couple times. Good luck and I hope you have found your problem.
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If it is below the O-ring it shouldnt cause a leak, just some tips now that you have it off, spray carb cleaner in the fuel rail and see how much crud comes out and repeat until nothing comes out, also when you go to put the injectors back in the rail a little vaseline on the O-ring helps the injector go back in the rail.
so now i have swaped plugs, plug wires, coils, and injectors and the misfire is still staying wtih cyl 4....now where do i go from here. how can i test the computer to see if it is doing its job. Please help i need to get my car back on the road.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by Boosted 99 TA
so now i have swaped plugs, plug wires, coils, and injectors and the misfire is still staying wtih cyl 4....now where do i go from here. how can i test the computer to see if it is doing its job. Please help i need to get my car back on the road.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by Boosted 99 TA
yeah i havea loud tick i had exhaust work done and i know it is leaking but the last few days it seems like it has been getting worse.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Originally Posted by Boosted 99 TA
how do i do a leak down test, and where can i buy the tools..should i avoid starting the car? thanks for the help i appreciate it
There's a special gage/tool that you'll need. When you test the cylinder, you want it to be at TDC for best results. The double-gaged tool will plug into the spark plug hole much like a compression tester. You'll need this tool plus an air compressor. You will be forcing compressed air into the cylinder, and you can regulate the amount of air with the tool. One gage will measure the amount of air you're forcing into the cylinder, and the other will measure the amount of air that is being lost (in percentage format). While doing the test, you'll be listening for where (if anywhere) air is leaking out. Listen in the following areas:
Air leaking back through the intake: intake valve issue
Tailpipe/exhaust leaking air: exhaust valve issue
Air leaking out of open oil fill cap: ring issue
Could also be a head gasket if none of those produce results, but the gage still shows a pressure loss.
However I doubt your issue is related to rings or a head gasket, unless you have other symptoms like oil/coolant mix or massive oil usage. Plus if you have ticking/tapping it points more towards a valvetrain issue than gaskets/rings.
Last edited by RPM WS6; Nov 28, 2006 at 09:03 PM.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
I think it's just called a "leakdown gage/tester". That's all I've ever heard it called.
The only one I've ever seen belonged to my buddy with a local repair shop. His was from MAC tools. I'm sure all the big name automotive tool brands sell one though....
The only one I've ever seen belonged to my buddy with a local repair shop. His was from MAC tools. I'm sure all the big name automotive tool brands sell one though....