I'm really hating my car right now...

[Brute03]

my car has been misfiring for some time now but it just refuses to throw a code. at idle, it pops frequently accompanied by engine shake, it bucks while cruising down the road especially when i get back on the gas after changing gear. it also hesitates and then jerks real hard if i punch the gas in 5th and it's a real pig at anything under 3k, i used to be able to roll into the throttle from idle and just roast 'em but not anymore

so far i've changed the fuel filter, plugs, cleaned the MAF and seafoamed it to hell but it still runs like crap. i recently pulled the plugs again and they all had a brownish-reddish tint on the ceramic at about 800 miles. so yesterday i tested the COPs and i got values ranging from 6.13K - 6.27k for secondary and .9 for primary all across the board, is this right? guys i'm really stumped on this one, thanks (wow this got long quick)

 

[Mike97gt]

what are you running for plugs?

your problem could be a intermintent coil problem, you need to try and test it while it's acting up..

as a last resort go to a ford dealer and have them run a power balance test while you drive this will point out what cylinder is droping out.. then swap the coil around and see if it moves from the cylinder that was misfiring to the cylinder you moved it too.

 

[SICK98STANG]

My bro's 96 had a similiar problem when he was idle the car would shake every now and then and want to shut off. So he checked the cable and they seemed fine, but the car was misfiring and he had to replace his secondary coil, and it solved his problem. So if your having the same problem it might be that. Let me know if that helps http://forums.stangnet.com/images/smilies/thumb.gif

 

[Brute03]

i'm running autolite 764's and the car is always acting up, it has no balls whatsoever down low, i really have to lay on the pedal to pull away from a light. are the COP's in spec based on the readings?

 

[stangGT97]

My bro's 96 had a similiar problem when he was idle the car would shake every now and then and want to shut off. So he checked the cable and they seemed fine, but the car was misfiring and he had to replace his secondary coil, and it solved his problem. So if your having the same problem it might be that. Let me know if that helps http://forums.stangnet.com/images/smilies/thumb.gif

wheres the secondary coil? I thought the primaries/secondaries were all integrated into the coil pack unit

 

[SICK98STANG]

Well there's two ignition coils one is primary and one is secondary from what the Haynes Manual states. I'd look to the Haynes Manual to double check but I think the secondary one is the one on the drivers side. That's the one I swapped out.

 

[BurningRubber]

i'm running autolite 764's and the car is always acting up, it has no balls whatsoever down low, i really have to lay on the pedal to pull away from a light. are the COP's in spec based on the readings?

Sounds like my problem, im running 764's aswell with the origional (I beleive) Motorcraft COP's. It pisses me off how much of a slug it can be off the line, part of the reason im not driving it right now.

Im about to be a test mule and buy some Grenatalli COP's...

 

[stangGT97]

Well there's two ignition coils one is primary and one is secondary from what the Haynes Manual states. I'd look to the Haynes Manual to double check but I think the secondary one is the one on the drivers side. That's the one I swapped out.

Primary and secondary don't refer to coil pack location. The primaries are the leads where the plug wires connect, the secondary is where the wiring harness connects.

Brute03, sorry to hear your car is still giving you trouble. Are your plugs fouled? Gapped properly?

 

[Kilgore Trout]

 

[Brute03]

yea they're gapped right, but what puzzles me is the reddish tint on ALL of them, especially considering that they're pratically brand new

 

[stangGT97]

yea they're gapped right, but what puzzles me is the reddish tint on ALL of them, especially considering that they're pratically brand new

Reddish tint... hmmm I have no idea what that is. Did you get water into the plug wells, causing rust?

 

[csledd]

whenever i installed my cams I accidently poked a hole in one of two of the rubber boots connected to the COP's and it caused it to miss out like crazy and it never threw a code for me either.. after I replaced all the boots everything was fine again.

 

[Brute03]

well i washed the boots in soap and water and cleaned them up real nice but i didn't see any holes, are they sold separately? and what should the resistance of the coils be?

 

[Mike97gt]

those coil readings sound ok.. do you have access to a scan tool that can give you live data.. I would like to see what the maf voltage is.

 

[Brute03]

no, i cant get one but wouldn't something like that throw a code? and what about o2 sensors?

 

[Mike97gt]

no, i cant get one but wouldn't something like that throw a code? and what about o2 sensors?

no somtimes it won't thorw a code. thats what makes EEC diag so much fun, they don't always throw codes and even when they do the code might not be the root cause..

no 02 sensors will not cause your problems. I really need fuel pressure and maf readings.

 

[88CougarMan]

Bad O2 sensors will cause similar problems, but they will usually throw a code. Your MAF could be fried too.

 

[88CougarMan]

no 02 sensors will not cause your problems. I really need fuel pressure and maf readings.

My O2 sensors were shot one time on my 5.0 and it was causing a part throttle hesitation and bucking. My brother has a '01 Bullitt and his car was doing the same thing you described, he had the Ford dealer check it out and one of his coils were bad. It fixed the problem.

 

[96SCstang]

ok, this is a very common problem on the 4.6 and 5.4 truck engines as well. the coil springs in the spark boots get corroded and dont work properly. yes putting a new COP will fix the problem because you got new boot also. i would try putting all new boots on the coils and i bet your problem will go away!!! see it all the time up here in my michigan shop.

 

[Mike97gt]

My O2 sensors were shot one time on my 5.0 and it was causing a part throttle hesitation and bucking. My brother has a '01 Bullitt and his car was doing the same thing you described, he had the Ford dealer check it out and one of his coils were bad. It fixed the problem.

the older EEC IV system in your 5.0 was much more sensitive to a bad 02 sensor than the much more advanced logic in the EEC V.. a EEC V can figure out based on other sensor readings that it's getting bogus readings and light off one of the 10 or so codes in the p1130-p1158 range... you can tell when the PCM thinks it's bogus because it will be a " sensor indicates lean/rich"

there are many differences in how EEC IV ( pre 1996) and EEC V operate,.. some of the old rules of thumb do not cross over to these cars.