Can’t use scan tool says will not connect to ecm???

 

Okay so scan tool showed no codes and no stored codes. However I did have the battery out for a few days charging it so they may have erased. Starting fluid did not cause it to fire. I did hear the fuel pump when you turn the key. So recap. All new coils and plugs. Good battery voltage no codes and will not fire using started fluid. Any suggestions

 

Verify that it's getting spark. There are videos on youtube for this. If it's getting spark, I'd start with the crank sensor. See if you can buy it from somewhere with a return policy. Basically you'll be throwing money at it without the codes but yeah, crank sensor first. Mopar brand.

 

Crank sensor got it to start but not idle and it runs very rough. it threw a code P1391. from what i gather is the timing chain tensioner code. the car does have a chain slap sound as it runs as well. Here is my question now, the cat has 200,000 miles on it, would it be wise to replace the entire timing belt and tensioner with that many miles

 

That's intermittent cam or crank sensor signal.

What brand sensor did you install?

 

Master pro is all they had, But that does not explain the timing chain noise. I watched a video that had a jeep in it that made the same noise and said it was timing tensioner. So would a sensor make the chain noise if the sensor was intermittent? I tried to get mopar and i can order one this week if the thought is that the sensors cause the chain slap bc the signal is intermittent. i was trying this bc it was available

 

On the 4.7, if you are hearing timing chain noise, it is probably a VERY good idea to go digging, and see what you find. Don't want pistons meeting valves. That would suck.

 

Found a good video on replacing the chains and tensioners. Of course, it's always easier with the engine removed, squeaky clean and on a stand LOL....

 

so even with the high mileage you feel like it would be good to swap the chain and tensioner

 

Aren't they listed as maintenance items somewhere?? Normally, I would expect chains to last a good long time, but, they DO stretch, and even hydraulic tensioners can fail for a multitude of reasons.... (Just ask GM..... Quad 4 engine anyone?) If it's making noise, then it is definitely time to at least have a look.