bigbrainonbrad
bigbrainonbrad Reader
9/8/20 5:58 p.m.

Wife was driving our 2015 Grand Caravan home and it started running rough on her. I started it up and it felt like a misfire. Codes show cylinder 1 misfire and injector issue. Put a screwdriver to the back of it and I don't feel it tapping, whereas I feel a tap on the other injectors. Getting voltage at the harness connection, injector itself shows no continuity which to me says it is bad.  Am I right on this before I get the parts overnighted from Japan?

Secondly, doesn't smell like unburnt gas out the tailpipe, in the oil, or out the intake manifold. Safe to drive it a little or not?

Jesse Ransom
Jesse Ransom GRM+ Memberand UltimaDork
9/8/20 6:11 p.m.

Last item first, I don't like driving anything that's running that badly, but that's just me, and not an answer as to whether it's damaging itself. I suppose probably not badly if at all? Drive it to the corner store and back, yes; commute all week, no? It would give me serious heebie-jeebies, and I don't think I could do it unless I had to.

Totally open circuit on injector resistance sounds bad to me, too, but just as a sanity check for whether you've got the ohmmeter ranged correctly and all, just test a working sibling?

bigbrainonbrad
bigbrainonbrad Reader
9/8/20 6:23 p.m.

In reply to Jesse Ransom :

Awesome point on checking a known good injector. One right next to it is reading around 16 ohm.

Robbie (Forum Supporter)
Robbie (Forum Supporter) MegaDork
9/9/20 9:42 a.m.

I'd avoid driving it much, as I hear that anything far off of the correct AFR can damage the cats pretty quick. And cats are not cheap. 

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
9/9/20 9:45 a.m.

I'd drive it. All the heat in the cats comes from fuel. Less fuel, less heat. Fords actually do this proactively, where if they detect a misfire on a cylinder for long enough they disable its injector. My buddy that had his v10 RV shoot out a spark plug drove all the way from Arizona to Texas with that one injector unplugged. 

If there is no continuity across the injector, it's broke! Replacing that should solve the issue. 

APEowner
APEowner GRM+ Memberand Dork
9/9/20 10:46 a.m.
Vigo (Forum Supporter) said:

I'd drive it. All the heat in the cats comes from fuel. Less fuel, less heat. Fords actually do this proactively, where if they detect a misfire on a cylinder for long enough they disable its injector. My buddy that had his v10 RV shoot out a spark plug drove all the way from Arizona to Texas with that one injector unplugged. 

If there is no continuity across the injector, it's broke! Replacing that should solve the issue. 

I agree with all of this.

bigbrainonbrad
bigbrainonbrad Reader
9/9/20 11:21 a.m.

That is actually pretty clever on the OEM's part that can save the end user significant amounts of money on repairs. I somehow highly doubt most people on the receiving end of the repair bill acknowledge or appreciate it though.

bigbrainonbrad
bigbrainonbrad Reader
9/11/20 6:02 p.m.

Thoroughly confused now. Replaced the bad injector with a good new one. Now I still have the misfire but instead of just P0201, I now have P0201 through P0206. Drove it around a bit pulled the battery cables cleared the codes and it keeps coming back! Ugh!

Stefan (Forum Supporter)
Stefan (Forum Supporter) GRM+ Memberand MegaDork
9/11/20 6:15 p.m.

In reply to bigbrainonbrad :

Pulling the cables means the car has to learn and now you have to go through an entire drive cycle.

Next time, clear the codes with a scanner and see if things get better.

bigbrainonbrad
bigbrainonbrad Reader
9/11/20 6:25 p.m.

In reply to Stefan (Forum Supporter) :

I've cleared them drove it and rinsed and repeated several times. No change after a several minute drive.  Codes appear within a few seconds of starting the engine every time.

Vigo (Forum Supporter)
Vigo (Forum Supporter) MegaDork
9/12/20 12:01 a.m.

I assume you mean 0301-0306? Those are the numbers for misfire codes. 200s are something else. Any chance you removed the intake during this process and may have introduced a large vacuum leak?

bigbrainonbrad
bigbrainonbrad Reader
9/12/20 5:34 a.m.

In reply to Vigo (Forum Supporter) :

The codes are 201 through 206 which is an injector circuit malfunction. Had 201 and 301 which pointed me towards the failed injector on cylinder one, after replacing it, now there is a circuit malfunction on all cylinders.

The intake system and upper manifold were off; however there isn't and audible or visible leak. Idle is just fine, no signing or hunting.

Streetwiseguy
Streetwiseguy MegaDork
9/12/20 7:31 a.m.

Did you get the correct injector?  Is the misfire fixed?  I wonder whether there is a mismatch on the new one causing the amerage requirement to change for the driver.

Odd problem.

bigbrainonbrad
bigbrainonbrad Reader
9/12/20 8:53 a.m.

In reply to Streetwiseguy :

It's the Mopar part ordered from Rock Auto. Confirmed the part number via numerous sources.

Pete. (l33t FS)
Pete. (l33t FS) GRM+ Memberand MegaDork
9/12/20 9:22 a.m.
bigbrainonbrad said:

That is actually pretty clever on the OEM's part that can save the end user significant amounts of money on repairs. I somehow highly doubt most people on the receiving end of the repair bill acknowledge or appreciate it though.

Most automakers will cut fuel to a heavily misfiring cylinder.

 

Highest priority is keep the converter happy, short term and long term.  That is why misfires will cause the check engine light to flash and not just come on.

Jesse Ransom
Jesse Ransom GRM+ Memberand UltimaDork
9/12/20 2:38 p.m.

Reseat any connectors you touched during the process? Sounds like those codes are about not seeing the expected electrical behavior, so any issues with either supply voltage or grounding could result in the numbers looking squiffy to the computer.

Just for giggles, ohm the new injector as a sanity check that it's electrically similar to the old ones? It *should* be, of course. One less thing to wonder.

bigbrainonbrad
bigbrainonbrad Reader
9/12/20 2:42 p.m.

In reply to Jesse Ransom :

I did check the new one, don't recall the value but it was similar to the others I tested. Ran through all of the connections I undid and made sure everything was where it should be.  I threw in the towel as SWMBO needs the family truckster.

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