Misfire dilemma...

When I took it to Ford to have the Trans service, the service guy told me there was a misfire detected by his computer, but he wouldn't give me anymore detail than that, of course for $109 he would have.

I don't know the best way to describe it, but at idle and low speed/rpm, there is a hesitation that is quite random. If I am at the back of the car with my hand over the exhaust, it feels like a timing issue almost or like the occasional smokers cough. Missing is coming from both sides randomly in the exhaust, there is no real pattern to it. I am leaning towards the CPS, so I am replacing that tonight or tomorrow. I have bought the CPS, EGR valve and a new PCV that I haven't put in yet, but time is never a commodity that I have frequently.
 
Cam and Crank Sensor wont make a miss...
cam sensor is only used at start up.. to ID the cylinders..after that it's ignored.
Crank sensor either works or doesnt..usually.. not really a missfire causer.
 
OBDII in general will identify the cylinder - on any scanner. There is also a separate code for Random Cylinder Misfire. Somehow, it is missing without throwing any codes that are detectable on an ordinary scanner, only on Ford's diagnostic machine.

Anybody know what the specs are to determine what codes will show up on OBDII and what will only show on Ford?

From here, I'm beginning to think the thing to do is shop around a couple of Ford stealerships to see who will do the cheapest diagnostic ($109 is a bit much). Let them run the diagnostic, pump them for information, and see what that turns up. We are obviously not going to find the solution knowing what we know now, and TJ is only going to go broke randomly replacing parts. I really want to know what a diagnostic will turn up.
 
Man now my car is showing a misfire in cylinder 2 :mad: which one is that?need to get some boots today-i got that switch for a/c-now the fan works but no cold air?
 
Last night I filled up with Premium Shell V-Power and dropped in some Injector/Fuel System Cleaner and a new PCV valve. Tonight I am going to change the fuel filter and go from there. It seemed to run a bit better today, still stuttering at idle just not as much.

9_8_L_S_C -

They have the boots in stock at Lee Auto Parts on Ogden Ave, about 2 miles west of Cass. They are $4 each and OEM parts if you can't find them elsewhere. In fact, those guys actually had all the parts I wanted in stock (tie rod ends, wheel hubs, 02 sensors, etc..) but I have to budget myself =)

No cold air? Blend Door? I only say that because I remember you telling me that it was holding the freon without leaking.
 
TJ I still wonder if you have a leaking injector. In my shop here we have always used Bg44K additive, it is what the dealers use and charge out the a** for. I just used two cans on a 02 Sport trac that would not idle right. She is smooth now. If you are using over the counter injector cleaner and it says one bottle to a tank put in two. Over the counter is not as concentrated so if the label says bottle to a tank I will use a bottle to half a tank. Still tryin to help.:D :D

also 98 LSC a cylinder miss is almost always wires. Change them all and plugs if you can should go away.
 
If you have read the thread, you will see that I have changed the plugs, boots and coils, so I have eliminated that as a source of the issue. I put in 2 bottles (16oz) of Prestone Fuel System Cleaner and a full tank of Shell V-Power Premium last night, but of course I always use Shell Premium anyways. Thanks for your input tho and thanks to everyone that has contributed, I'll narrow this down yet, hopefully the fuel filter change tonight will have additional results.
 
Yes, I did check the vac hoses/lines and the intake tube, all was fine, although some of the vac lines seemed to be getting dry rotted, I have picked up new lines and connectors and plan on redoing them anyways.

Thanks
 
hey do you still have the part number for those?hopefully i am working up in that area in the next couple of days so i can drop in and get some.
 
I haven't had a chance to do anymore, due to family and work, but I will be digging back into it today probably. I will get the fuel filter changed today and then go from there. I did manage to win the AUTOTAP USB setup on Ebay, so I should have that probably tues/weds of next week, hopefully that will shed more light on the subject. Glad I have 3 OBDII vehicles to use it on, I know I surely could have used it on my other 2 as I have been working on those too. You know how it is, as soon as you get one car fixed, the smile of pride and accomplishment fades quickly as another vehicle develops an issue to be looked into.

Thanks and cross all your fingers.....
 
Update-

I got my AutoTap setup last night when I got home. Installed the software, hooked up to the car and did the registration. Tonight when i get home I'll do some 02, TPS and Air/Fuel diagnostics and post the results here. I love new technical toys/tools like this, so i am sure I'll be checking everything under the sun =)
 
It's really nice to be able to actually "read" all the sensors, that's how we figured out the tps on my friends car wasn't working properly, and replacing it solved a ton of phantom issues.
 
Preliminary Scan results:

Seems that I have a 'lazy' O2 sensor in bank 2. Although it is working, it's slower than it should be on it's switching, so I guess I know what I'll be replacing this weekend(besides the fuel filter). Found them at my local parts house for $57 each, gonna do the 2 front sensors.
 
unless your getting a motorcraft 02 sensor for 57 bucks I'd leave the "non lazy one" in there.
The OEM sensor is far better than the 50ish dollar bosch sensors.

IF you take them both out, save the one that's "not lazy" so you can replace the bosch sensor on whichever side fails first....and.. it will fail.

...just a heads up
 
What's the oem manufacturer?

I know the factory O2's that came out of my Vic were NTK, which is supposedly part of NGK... just what I've heard.
 
They are not Bosch, they are Standard, OEM replacements. The usual proce of them is $87.56, but I have been going to this parts house for over 20 years and get them at cost. Bosch and Denso are not recommended by me or anyone else I have talked to, therefore I won't put them in my cars. Standard are exactly like the factory sensors.
 
Fixed

PROBLEM SOLVED!! YAY!!

Ok, it was a crack in one of the coil packs. I replaced the coils with a "known good" used set and the problem still remained. After getting my AutoTap and then getting the Enhanced Ford parameters today, I was able to dig deeper into the misfires. It gave me a LOW_WORD Misfire #7, so I pulled the coil and looked at it, sure enough....

coilcrack.jpg

I then put the coilpack in a diff cylinder just to make sure, and it followed. Put a new coil in and VOILA, purrs like a kitten. Still got some good maintenance out of it

Trans Service
02 Sensors
Fuel Filter
Coil Boots
Plugs
Seafoam Treatment
Air Filter
Oil Change (only had 800 miles on the oil, but figured what the hell)
and bought the AutoTap

All this: about $400 and worth it!!!

Thanks for all your help and if your in the Chicagoland area and need a diagnostic scan, let me know and I'll take a minimal donation for the service:shifty:

What is hard for me to swallow is that I borrowed some coils from a known good set and got the same problem, what are the odds? Turns out what my friend wasn't telling me is that he has been having very minor studdering problems, not as harsh as mine were, but then again, I'm anal about the way my cars run.
 
Awesome mang!

It's always nice to finally fix that nagging issue...

I hate COPS btw... and not the kind that eat donuts lol
 
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