using a multimeter to check coils etc..

[ripped camel]

Can anyone give a walkthrough on how to use a multimeter to check the coils and also the IAC?

I also need the factory specs of what range the coils should be in, and IAC should be in.

Thanks.

 

[LaserSVT]

Sure! Heres how you use a multi meter to test them........ YOU DONT!!!

The pulse is around 30-40K volts. Most meters will not read any where near that. Plus the pulse is so fast that even if you did have a meter that could read that much you still wouldnt see the peak even with a peak hold.

You can test to see if the coil is getting voltage but again you need a fast meter with peak hold. Its uber rare for power to not get to the coil though.

Ford dealers and some better performance shops have one of the $10,000 scaners that hooks to the OBD port and can read each coil to tell you which one is bad and how bad it is. When my car was being tuned they tested mine and showed two very very weak coils and two on the edge. I said screw it and bought 8 new coils. I found a place on ebay that had them brand new for $18 each shipped. The ad said OEM part not OEM replacement part so they are generic. Meh, eventually I will buy some MSDs (more power but short life span) or some real OEM ones again.
For now these work. I only have 500 miles or so on them but the car definatly starts faster, idles better and picked up 15 hp with them but thats just cause my old ones were..... well, old.



Anywho, point is you need to have it scanned to see what coils if any are bad. Of course you could just replace all of them which IMHO needs to be done on any modular over 100K miles.

 

[ripped camel]

And I'm taking it that scanner that shops have is different from basic X3 datalogging?

 

[LaserSVT]

Prolly not. Why would a $10,000 professional scan tool thats only issued to Ford dealers be able to do something a $300 little hand held programmer cant?



/sarcasm

 

[Tiltedhalo]

Set your ohmmeter to the 20000 ohms range. Turn on your meter and touch the spark plug wire terminals on one of the coils with the meter leads. You may get a reading between 5000 to 15000 ohms, depending on your particular model. This checks the secondary resistance.
Set your ohmmeter to the 10 ohms range, and touch the terminal B+ (usually the center prong on the coil pack electrical connector) with one of the meter test leads, and touch the corresponding coil prong on the electrical connector with the other test lead. You may get a reading between 0.3 and 1.0 or more, depending on your particular model. This checks the primary resistance on each coil.

 

[98lincmk7lsc]

the little $3,000-$4,000 Snap-On scanners work too...

 

[BAD97LSC]

so wtf is wrong with it now? you called me after you left the shop saying it was screaming and running like a champ, then you have a baby and dont let anyone even know, then you come back on here talking about coils and iac valve obviously its running like crap again. it always runs good after you reset the computer, everytime you have erased the codes and driven it it runs fine, you need to fix the exhaust dude, you need your pre-cats back on the car. the more i see the car and all the crap you have tried and nothing seems to do any good i'm putting my money on the whole problem leads to the fact that your stock cat shells are on the car and you have nothing inside of them, they shouldnt have ever been gutted ever, 3rd cat sure cut it off, two pre-cats no leave them alone.

 

[ripped camel]

so wtf is wrong with it now? you called me after you left the shop saying it was screaming and running like a champ, then you have a baby and dont let anyone even know, then you come back on here talking about coils and iac valve obviously its running like crap again. it always runs good after you reset the computer, everytime you have erased the codes and driven it it runs fine, you need to fix the exhaust dude, you need your pre-cats back on the car. the more i see the car and all the crap you have tried and nothing seems to do any good i'm putting my money on the whole problem leads to the fact that your stock cat shells are on the car and you have nothing inside of them, they shouldnt have ever been gutted ever, 3rd cat sure cut it off, two pre-cats no leave them alone.

Yeah the wife went in Sat to be induced for labor and they ended up having to do an emergency C section which resulted in her bladder being knicked during the surgery. We just got out today. Poor girl is all messed up now. Breaks my heart. My new son is doing great and his older brother loves having a new addition.

The car acted up yesterday but is running fine today. I still think it's IAC, TPS, coils or something else like that. It has to be electrical. There is no way for it to intermittently give me issues.

I'm going to have the dyno tune done with wideband o2 reading to ensure it's spot on, but before I did that I wanted to alleviate the basics iac, tps, coils. It would suck to pay for a dyno tune to find out it wasn't tuned right because of an outside failure.

 

[mikemark8]

Set your ohmmeter to the 20000 ohms range. Turn on your meter and touch the spark plug wire terminals on one of the coils with the meter leads. You may get a reading between 5000 to 15000 ohms, depending on your particular model. This checks the secondary resistance.
Set your ohmmeter to the 10 ohms range, and touch the terminal B+ (usually the center prong on the coil pack electrical connector) with one of the meter test leads, and touch the corresponding coil prong on the electrical connector with the other test lead. You may get a reading between 0.3 and 1.0 or more, depending on your particular model. This checks the primary resistance on each coil.

+1-they are easy to check out by measuring resistance, with a $20 meter

 

[brentalan]

congrats on the new baby!

 

[Sapperfire]

Ok off topic...grats on the baby...so WTF..are there any women anymore that DONT get emergency C sections? Both my Xs had C sections, and my current had one..I'm thinkin doctors just like to cut

ok back on topic

Why!!!!In!!!!!The!!!!Hell!!!!Are!!!!You!!!!Running!!!!Gutted!!!!Cats!!!!??????

Dude go get Cats...please don't ask LVC for ANY more advice about fixing your car until you FIX YOUR CAR...giving everyone headaches

 

[philly0420]

Congrats on the baby. Just found out I'm having a boy today.

 

[LaserSVT]

Congrats on the baby. Just found out I'm having a boy today.

Whos the father?

 

[ripped camel]

+1-they are easy to check out by measuring resistance, with a $20 meter

Cool, I'm going to have to learn how to work with one of those.

congrats on the new baby!

Thanks

Ok off topic...grats on the baby...so WTF..are there any women anymore that DONT get emergency C sections? Both my Xs had C sections, and my current had one..I'm thinkin doctors just like to cut

ok back on topic

Why!!!!In!!!!!The!!!!Hell!!!!Are!!!!You!!!!Running!!!!Gutted!!!!Cats!!!!??????

Dude go get Cats...please don't ask LVC for ANY more advice about fixing your car until you FIX YOUR CAR...giving everyone headaches

Thank you

Congrats on the baby. Just found out I'm having a boy today.

Thank you and Congrats to you too.

Whos the father?

Jamie's the father

 

[94m5]

On topic again......

I'm glad that someone posted the method to ohm them out. I have an intermittent miss on my 6.8L v10, and was looking for that info.

Off topic again, Congrats on the baby!!!


On topic, Could we keep from pulling this guy apart on a public forum? Why can't the drama be kept to PMs??

Mike

 

[BAD97LSC]

well i let you try that other iac and that didnt help, you can try another one if you want, i can also try changing the tps with one off a throttle body at the shop but i think you are chasing a gay parade with a jug of vaseline at the end. i dont think its gonna help, yes i am negitive.
congrats on little derek, he's gonna be ripping parts of his power wheels if he watches how you work on your car lol!!!

 

[FASTLLS]

Congrats on the kid..

 

[ripped camel]

On topic again......

I'm glad that someone posted the method to ohm them out. I have an intermittent miss on my 6.8L v10, and was looking for that info.

Off topic again, Congrats on the baby!!!


On topic, Could we keep from pulling this guy apart on a public forum? Why can't the drama be kept to PMs??

Mike

Thanks Mike

well i let you try that other iac and that didnt help, you can try another one if you want, i can also try changing the tps with one off a throttle body at the shop but i think you are chasing a gay parade with a jug of vaseline at the end. i dont think its gonna help, yes i am negitive.
congrats on little derek, he's gonna be ripping parts of his power wheels if he watches how you work on your car lol!!!

That was freaking hilarious! Jamie here's the thing. The car is intermittently giving me problems. I can't imagine that one day the car drives great and the next day it drives like crap because of cats. It just doesn't make sense. The only part that would make sense is because of increased airflow, more fuel needs to be dumped in so the a/f ratio is off causing issues.

But that wouldn't cause things like the car barely going anywhere when dumping on it from a roll. The RPM's shoot up like it's trying to do what it's supposed too, but then it just sits there and barely moves.

I'm trying the TPS because my buddy works at a parts store and is letting me try it...he said if it doesn't work he'll return it for me. So why not alleviate that as a problem?

I've called around and talked to some shops about dyno-tuning so that will be done soon. It will cost around $150 for a dyno tune. Not bad...one shop wanted $650 for a dyno tune! HAHAHA! I laughed at that guy.

Congrats on the kid..

Thanks

 

[ripped camel]

So I swapped on a new TPS and although it didn't fix the stumbling issue, the car definitely accelerates a little better and is more consistent.