Intermittent miss?

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Kraze

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So my 97 developed an intermittent miss. It's noticeable most when it's idling and the start of accelerating. All I've completely ruled out as of now is spark plugs.

So, ideas on all the things it could be and solutions on how to fix it?
 
No codes, and I already did the search and my miss seems to be different from those. It's not steady or all that bad, but definitely noticeable.

So since it's an intermittent miss.. how would I test to see if it's the COPs? How bad is it driving with the miss?
 
I would change the boots first. They are cheap and a lot of the times are the problem even if they look good.
 
All the boots were changed less than a year ago. They all still look brand new, so I don't know if that's it.
 
I had the same problem on my 98, couldn't figure it out for the life of me so I bought an AutoTap diagnostic setup with the Enhanced Ford parameter module. I found the miss and when I inspected the coil, I found a hairline crack in it barely noticeable. Before that I had changed all the boots and even got a tranny service first because it was more like a studder under load than a miss.

http://www.lincolnvscadillac.com/showpost.php?p=426273&postcount=49
 
Most auto part places sell this light thing that attaces to the coils output to show if it is fireing. Just saw it on the Powerblock last weekend.
 
TJKashin said:
it was more like a studder under load than a miss.
Click to expand...

That's what mine is like! Except for it does it at idle too.

LaserSVT said:
Most auto part places sell this light thing that attaces to the coils output to show if it is fireing. Just saw it on the Powerblock last weekend.
Click to expand...

Intriguing. I'll have to see if I can find this around here. Thanks for the info.
 
maybe this will help test it with an ohm meter.

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I've read on other forums about ohm reading too. Can it read correctly if the miss is umder load? Wouldn't testing have to be justified while the car was running? Excuse the dumb question I'm a tard when it comes to electronics.
 
When I was checking for the miss I pulled the connection to each injector until I figured out which cylinder... when I figured that out I took the COP out and inspected it finding a small crack in the boot.
 
Unplug the coil at the wiring harness and in side where iit was just connected there should be two wire pins touch one with one probe and the other with the other probe if the ohm reading is within the specs then it is good too much resistance bad too low bad. no it doesn't have to be running.
 
What are the resistance specs for the COP's? (that diagram you put up is for injectors)
 
I meant to say injector not coil sorry. And no there is no ohm test just wavelength tests. which he would not understand anywho. Need to look at the live data and figure out which cylinder is missing, then trade that coil with another cylinder and see if it moves also. There should be codes this is an obd2 car.
 
Just had a thought. If this was a true misfire, would there have to be a code? I just checked for codes again, and got nothing indicating a misfire. Does this point to something like a vacuum leak instead of a true miss then?
 
Kraze said:
Just had a thought. If this was a true misfire, would there have to be a code? I just checked for codes again, and got nothing indicating a misfire. Does this point to something like a vacuum leak instead of a true miss then?
Click to expand...

Anyone?
 
Kraze said:
Just had a thought. If this was a true misfire, would there have to be a code? I just checked for codes again, and got nothing indicating a misfire. Does this point to something like a vacuum leak instead of a true miss then?
Click to expand...
vac leak will trip a check eng light too. sounds like a weak coil or injector
 
chicken said:
vac leak will trip a check eng light too. sounds like a weak coil or injector
Click to expand...

Fingers crossed it's not injectors then. I just ordered a set of 8 coils, so I might as well replace them and see if that fixes it and go from there.

I think this is the one time where I'm actually wishing for a code, just so it can point me in the right direction lol.
 
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