2001 Dodge Truck 5.9 L injector problem?

EARLAND7

MEMBER
2001 DODGE TRUCK
V8
4WD
AUTOMATIC
95,000 MILES

I have a 2001 dodge 1500 with a 5.9L and my check engine light came on, Autozone put a scan tool on it and it said number 5 cylinder misfire. I checked the spark plug and it looked good but I didn't test it, I didn't know how. I put an Ohm meter on the wire and the reading was 5200 Ohms, the wire is 20 inches long and the manual said 250 Ohm's per inch, so that fell within what the manual said it should be. So I ohm'ed the injector and the reading was 14.5 Ohm's, the manual says 12 Ohms +/- 1.2 Ohms. How do I check the spark plug and is there another way to test the injector? I don't want to buy an injector and find out that wasn't the problem.
Thanks for any help given.

1 Reply

CARADIODOC

MECHANIC
33,752 POSTS

Hi earland7. Welcome to the forum. Switch the spark plug with a different one, then erase the code by disconnecting the battery for a minute. Even if you don't erase the code, if the misfire code is set for the other cylinder, it's the spark plug.

From my extensive tv reair background, logic tells me the injector resistance is not an issue, ... However, injector resistance is fairly critical. To tell better, measure some of the other injectors. Remember, there will be some resistance in your meter leads that you must subtract from the readings.

In general, Chrysler has always had extremely little trouble with injectors, mostly because their supplier flow-tests them and sells them in matched sets. GM in particular just throws a handful of injectors into their engines and hopes they match close enough but they do cause a lot of misfire codes, often for misfires you can't even feel. Here again, you can swap two injectors to see if the misfire is detected for a different cylinder or the same one.

Caradiodoc