Hi there,

I posted 6 weeks ago about my Dakota having a P0300 Random Misfire code.

My truck has been in the shop for the last 6 weeks. Sensors have been tested and replaced where needed and components have been tested and confirmed as working.

The issue has been narrowed down to the engine being starved for fuel when it is cold. The garage has not been able to resolve why this is happening. They did say if I let it warm up for 5 minutes they are confident it will run fine after this initial task is done.

The bill is at $1800. No real repair has taken place.

Now with this narrow diagnosis, I wonder if anyone out there has an idea of what is causing my engine to be starved of gas while the engine is cold?

Also, I have suspected it is an electrical issue as the after market car alarm stopped working when the CEL came on and the stuttering began.

So, is the fuel system or a part of it possibly somehow on the same circuit as the alarm? Would a weakening component cause an entire circuit to stop working?

Any other ideas? This is costing a lot for no repair being done and as one would expect, it is frustrating as all crappin' hell.

Thank you for any input.

 

I do not know much about electrical issues with this truck, but one thing I do know is never pay a bill for a unresolved issue. I would be happy to pay a diagnosis fee, and work on negotiation on labor rates. If they buy parts and they did not fix the issue why should you have to pay for it.

 

After market alarms and remote starters are a touchy thing with Chrysler products. A lot of electrical problems have been associated with these add-ons. And the problems don't always rear their ugly heads right away, it can be a year down the road. A lot of times it's not that it is installed, it's that it is not installed correctly, or is a product not compatable with Chrysler. My friend just spent $800 at the original installer because his remote start quit working and engine was idling rough, with no positive results. On another friends recommendation, he took it to a different guy who removed the whole harness and said, "Yup, wasn't connected right for this car and caused this $16 connector to go bad. You better go back to that other guy and get your money back, cause he doesn't know what he's doing." So, sometimes it's the product, sometimes it's the installer. But, the alarm might need to be looked at, maybe by someone other than the installer. You've already been billed a good chunk of change by your mechanic. Unless you really, really, really trust this guy, you might want to get a second opinion on the tests and work he performed.(especially before fully paying the bill)

 

The only time I've ever seen p0300 is when the catalytic converter is clogged up And not allowing enough exhaust to exit.

A muffler shop should be able to check it by reading the temp. Or you could drill a couple of 1/4" holes in the pipe before the cat.

 

That would be annoying. The holes would make it sound like an old outboard motorboat. lol

 

any backfiring thru the throttle body? A clogged cat would not make it run healthy, also a leaking head gasket mat be the culprit also, is it the same cyl?

 

Head gaskets were checked and confirmed as all good. No backfiring. The problem jumps between cylinders, hence the random misfire code. I would assume they checked the fuel pump and system and the catalytic converter. I alerted them to the alarm issue three separate times but they did not seem convinced that the two things are related.

Will be receiving a detailed list of everything they checked and what was replaced and what was good on Tuesday or Wednesday.

I had my stereo and alarm installed at Future Shop and they have a lifetime warranty on installation so I think I will take it back there and have them get the alarm working again and see if that clears it up.

Checking with the BBB to see what my rights are when dealing with a mechanic shop where the repair hasn't been completed after various diagnosis and actions have been performed.

This shop has a stellar record with the BBB and a good reputation with all I have spoken with so we will see how this plays out.

Strange, strange auto problem. This is why I drove beaters for 19 years. Not paying more than $800 for a vehicle ever again. Stupid computers and sensors. Useless technology. Even a certified auto mechanic can't figure out what's wrong.

 

Not always true until you go monkeying around with the electrical systems installing systems and alarms. With todays computer controlled vehicles it's easier than ever to find out a problem. Provided the original factory wiring harness has not been hacked into. Like deerhunter says, these trucks are sensitive when it comes to the electronics. Don't know how hard it would be to put everything back to original but until you do, how are you ever going to know if thats the problem or not. I don't think anyone on here had a random misfire issue so it is definitely not common. Hope you get it figured out without too much hassle.

 

Random misfire code is so vague that getting one is the same as not getting any code at all. If the computer were to serve it's purpose correctly it would pinpoint what is causing the problem directly instead of telling you the symptom.

I used to be able to fix my vehicle myself short of an engine rebuild. Now to find out what's wrong it takes the computer talking to another computer and then endless experimenting with sensors and parts until the problem is solved...or in this case, not solved.

Computers and sensors may help vehicles run more efficiently, but they also increase the amount of components that can and will fail and cost you more money.

 

Random Misfire, Have they check the Crank Sensor?
Seeing you had a Alarm installed by futureshop, I would say that is the issue, One of the crappy splices they most likely did has become loose.
I thought of having a Remote Starter installed, and then decided away from it, I dont need morons touching my Electrical System, Same with the radio I spliced my aftermarket one I had in before myself, Altho the Radio is very simple and you cant mess a whole lots up with it.