Crazy Friggin Miss

tda13

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I have a crazy missfire going on. Had the codes run (which I don't completley trust) and it says missfire on number 6. The first thing I did was switch the coil pack and had the codes ran again... still number 6. That rules out the coil pack. I also stuck another injector in six (not a new one) and still the same problem.

When I first start the car the miss is not near as bad for about 30 seconds. Once the car starts to warm up, there it is. Also, at times during acceleration the miss is not there, but when it levels out the miss comes back. I have changed vacuum lines, egr, coil packs, plugs and injector on this one cylinder.

The car does have a slight tic on the driver side. I tried to tell where it is comming from by putting a rod on the valve cover and puttting it to my ear. Does not sound like the numb six cylinder. Could it be a broken valve spring or a bad cam lobe??? I would think the miss would be more consistant. Have not pulled a vacuum test yet or compression test. Thats today. Also have not pulled the valve cover off the driver side yet.

The car is a 97 with 180 on the clock.
 
Did you look in the plug well to see if there is any oil leaking in? I had that problem with my 98' and the oil shorted the plug out a lil then completely out. I cleaned the well out and put in a new boot an it's been fine since.
 
I did check for oil. Very little. In fact I replaced all the coil boots.
 
Wonder if the clip that hooks to the coil is loosing the connection? I also had a problem with that when I changed the boot. Might be a stupid small thing that is screwing you up :confused:
 
well first things first see before you replace things you should see what is wrong
did you check to see if it has spark at the plug if so then move on to the fuel system
then
 
well first things first see before you replace things you should see what is wrong
did you check to see if it has spark at the plug if so then move on to the fuel system
then

Yes. There is fire at the plugs. I have ruled out the coil packs (so far). I am leaning towards a fuel issue. Didn't get to mess with it much yesterday, but I did pull the number six injector out and replace it (not with a new one, but a newer one) just to see if it made a difference. It did.

The car starts and idles fine until it starts warming up (maybe 30 seconds). When I drive it, it misses during acceleration. If I get the rpm up to about 2200 and keep it there, it smooths out. When I stomp on it, it sometimes runs great and sometimes runs on seven cylinders and eventually picks up eight. Crazy.

Car has been setting since last October, but I had these issues when I parked it. I have 96 engine on the stand in the garage. I need to finish building it and stick it in.
 
Run a couple of bottles of Seafoam through if you haven't already, one through the tank and another through the top end.
 
Run a couple of bottles of Seafoam through if you haven't already, one through the tank and another through the top end.

Ran one through the top end. Not through the tank yet.
 
where do you put it in to run it through the top end?

I usually start the car and let it suck it in through vacume. This time, I had the throttle body off and was able to put in through the top before I reassembled it.
 
Sea Foam Procedure

i found the best way to do the Sea Foam Procedure is to have a friend sitting in the car. start it up, warm it up good. op temp....

then, pull off the brake booster vacuum line and pour the Sea Foam into the hose. the person in the car can keep the motor at approx 2K rpm. when the can is empty shut it off or let it die. hook the vacuum line back up to the brake booster and wait 15 min.

next step is important*.......
notify your neighbors that you are cleaning out your manifolds and not to call the fire department when they see the smoke.

your car is going to smoke like hell for 10 min.....seriously.

***you might want to wait till nighttime to do this in a crowded neighborhood....

start car up and rev it good, going from idle to 5K rpm. keep doing it until the smoke doesnt come out of the tailpipes anymore. about 10 min. be upwind of the smoke and keep all pets and kids out of it. it is nasty toxic smoke. your Mark VIII will thank you!!!;)

throw a can in the tank now if you like for de moisturizing the tank and fuel lines and cleaning the injectors and internals too.
 
Pulled the codes today and the misfire did not show up. I did get a P1451 code and a P1504. 1504 is the idle air control. I have replaced it with a new IAC when the problem started. Anymore ideas.
 
Check for a dead spot in the TPS.

Ok Mike, I probably should know and will probably feel stupid when you tell me, but what is the TPS and how do I check it. lol.
 
Throttle position sensor.

You will need an ohm meter, and will be checking for a smooth ramp of resistance as you move the throttle.
 
crank sensor

if its not a bad wire ,check by replacing the suspect wire of known quality if tha doesent do it id check the crank sensor .i replaced one as p.m. and three months later started acting up couldnt figure it out .well it was the crank sensor after replacing darn near everything else. when you change it get one from ford it really is a better sensor
 

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