ok so today i replaced both my coil packs and cleaned my IAC. because Cyl 1 is misfiring. after replaceing the coils i started my truck to find that....Cyl1 is still misfiring and didnt help at all. ive replaced the plug and the wire and that did nothing at all ive replaced everything for the igntion and im fresh out of ideas on what is wroge now. any one have any thoughts??? plz help me!

 

Have you had the compression on that cylinder checked? You could have a busted ring and it might not be an electrical problem at all.

 

Switch the injector.

JMC

 

im going to do a compression test today. what should it read? if the ring was busted wouldnt gas get into the oil? or oil all over the spark plug? i dont think its an injector as there is gas coming out of the exhuast pipe. i do have 8 injectors off a 94 police interceptor 4.6L ill switch it around and see what happends. other than Injector and compression is there anything else that could be wroge? thanks alot guys. by the way 4.6L truck made in windsor, canada. also is it bad to run the truck on 7 cyl's? i know it cant be good but its my only truck i have to drive i have no choice i have to drive it about 16 or so miles a day. how bad is this for my truck??

 

Dumping raw gas through catalytic converters is never good.

It's not what the compression test reads, it's the behavior compared to the other cylinders that counts - comparative pressure and the way the gauge jumps when it's pumping up.

 

ah....and what catalytic converters??? i have shorty headers and a custom bend down pipe with true duals and dynomax superturbo mufflers. i have no cats my rear o2's are simulated. thats another code that gets throwing. o2 Bank 1 senor 2 .o2 bank 2 senor 2. o2 circut mal****ion. the 4 codes i have. Cyl 1 mifire. 2. o2 bank 1 senor 2/ o2 bank 2 senor 2. 3. o2 circut mal****ion. 4. EGR insevesent flow. *the EGR code has been on there for about a year so its nothing new. how can my rear o2's be throwing a code they're simulated all they are doing is lieing to the computer.

 

Last time he pulled the plug , he said it was black - not wet in another thread.

JMC already gave some good advice - in-fact everyone has and I have told you -NO cats = bad news all around . You have no back pressure. I would at least have a high flow in there since there O2 friendly.. The motors are programmed to run and adjust a certain way and if everything don't jive, how is it going to adjust properly. The EGR system doesn't work very well without cats IMO and having at least one in there isn't going to hurt performance.

Regardless -

Check the injector - swap it

Compresion test

Wiring ...

I would go in that order myself..

 

my cylinder 5 misfire was a bent valve. 1700.00 later i am back on da road woo.

i also replaced everything electrical and finally tore it down to find the valve was bent.

kyle

 

what do you mean i have no back pressure?? everyone i talked to around here said it will have more back pressure with the dynomax mufflers insted of cats. the EGR code came up while it had stock everything my moding didnt make that come up. The front o2 senors are in and working fine i thought the back o2 senors just tell the computer if the cats are working or not. im going to do a compression test tonite most likey and going threw everything step by step going over all spark plug wires looking at my o2 sims and everything. what does Circut mal****ion mean? other than its not working tonite is going to be a fun nite keep an eye out for posts on here about whats going on with my truck. And thank you all for ur advice and input it was very helpful i really do mean it guys thanks a million!!

 

You ask for advice , you never take any of it I don't know who you talked to that told you to remove ALL the cats - there wrong or you didn't understand what they were saying.. Quit asking questions and check out what people have told you to. That's your best bet at this point. That way , you'll stop getting the same answers to the same problems.

 

Let's back up even more - what makes you think your truck is going to run better by essentially ripping out the whole exhaust system anyway? If you want noise and better breathing, just hang a catback on the stock setup. Shorty headers and no cats throws the entire system out of balance and requires custom tuning.

 

i have i cleaned my IAC it idels higher just like you said im going to see if this boxy thing can go back on with my CAI. i replaced my coil packs like people have said to. ive taken alot of advice just not enogh but im going to do everything 2 nite that everyone has said. thanks again!!!

 

Yea , I tried to look that up for yuh in the past and found nothing - well , it's been called an IAC controller . For some reason , I don't think that's the proper name. The 5fours have the IAC in the back of the TB and have a round type deal in between the intake and IAC instead of the box you have on your 4six. My guess is that it governs the flow into the IAC for proper idle ciphering..I'm surprised theres not much talk about it here.

 

The little box, 4.6, or the Barrel, 5.4, acts as a muffler.

JMC

 

This guy's major mistake is wanting to be told what and how on everything.
Now he's in trouble with it and can't figure anything out himself and STILL want's to be told what's wrong with all the issues involved.
More than one problem at the same time is sometimes a bitch!
You need:santa: