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IndianaVX
03/14/2011, 05:58 PM
in trying to eleminate a PO300, i am at the point of wanting to measure the resitance of the coil packs. in my manual, it tells what terminals to touch, but i dont even know how to set my eletrometer thing to measure resistance.

the manual says the limit is "Without 0 ohm or infinity maximum ohm" when terminal 1 and 2 are touched

when 1 and 3, and 2 and 3 are touched the limit says "Same as above" or "Without 0 ohm or infinity maximum ohm"

i am completly lost.....but i cant get the truck above 40, and if there is a hill, i will get a flashing CEL, (PO300) along with looks from other drivers passing me, lol .......ive replaced air and fuel filters, cleaned the egr, ran seafoam,(in a strong solution) in the gas, replaced fuel pressure regulator, cleaned and inspected the MAF, got the timing covers off right now, and everything lined right up. i also replaced the sparkplugs with ngk irdium. the truck is just running so sluggish

here is the pic of electormeter thing i got and im using.
on the ohm scale, (in grey) i have 20M, 200k, 20k, 2000,200, and an arrow pointing at a plus sign looking symbol.

i need to get out more, or trade up on some friends, cause everyone ive called around here dont have a clue. lol


http://www.vehicross.info/gallery/data/500/thumbs/110314_001.jpg (http://www.vehicross.info/gallery/showphoto.php?photo=20327)

Y33TREKker
03/14/2011, 08:36 PM
Going by what you've said , I'd say setting the meter on the 20M scale, then taking the measurements between the terminals you've listed should yield the equivalent of an overlimit or infinity reading each time if the coil packs are good. My meter reads "OL" on the display for an infinity (infinite resistance) reading, but not all meters register the same, so yours may be different.

That's assuming that what the manual means when it's saying "Without 0 ohm or infinity maximum ohm" is that the reading should be infinity.

Grif
03/14/2011, 08:40 PM
Set your meter to any ohm range. 200 is fine. Any reading greater than zero between terminals one and two, and one and three, and two and three indicate good. If any of those readings are zero on your meter then you have a bad coil.

At least thats how I'm reading this.

You are actually testing for continuity, not an actual ohm (resistance) reading. According to the text, as long as those terminals in that combination have continuity, yer good. And any number between 0 and infinity demonstrates continuity.





http://1dl.us/gar.jpg

IndianaVX
03/22/2011, 07:42 PM
A final summary to my PO300 code. After replacing air filter, fuel filter, fuel pressure regulator, cleaning EGR, EGR tube, and trottlebody body, and still having poor acceleration, and performance, I was down to either fuel pump, or catalytic converters. I found a muffler shop that would test the pressure fore and aft converter. Passenger side had 1/4# restriction, riverside had 10# restriction!!!! This is the side I had the blown head gasket in December. I guess it just took a while to fAil, but never got a code other than PO300.
So same muffler shop got me out the door 250.00 with an aftermarket cat!
Truck is running great again, like the day I bought it!!!
One of my pet peeves is someone having a problem, posting said problem, discussing said problem, and then never posting solution, or if it ever even got fixed. So now, I won't tick myself off!

Sluggish, PO300, poor performance, poor acceleration, chugging, gurgle

Grif
03/22/2011, 07:55 PM
Thanks for that. Replace the cat.

Interesting, I'd never think a restriction in the cat would cause a misfire code to be thrown. But I guess its possible.

IndianaVX
03/22/2011, 09:26 PM
Well thank you griff for posting the pick from the manual. You too trekker. I got alot of numbers from my testing of the coils. And As you said, any number showed resistance, but writing down all the numbers, although pretty close, none were the same, but probably a tolerance thing. But judging by the numbers I got, I know whAt coil is stronger/weaker by the number. That's gotta be good for something......at least the graph I made looks cool! Lol
Thanks again!