Hi,
I have a 1995 dodge Dakota 5.2L. I've been having some problems at idle and lower rpm range (under 2000) my truck runs rough back fires and seems to be running rich. so far I've replaced plugs, wires, cap and rotor, idle air control, map sensor, 02 sensor, throttle position sensor, cam sensor, distributor drive gear and bushing, intake manifold pan and gasket, and timing chain set with tensioner. nothing seems to have made a difference. Any ideas?

 

Ya, stop throwing parts at it. You're just wasting money. Although that advice is a little late now.

I suppose you got these sensors at a part strore?

Yet another thread makes me glad I will only own 96 and newer vehicles. If it is a sensor wrong with my truck, 99% change a light will show and my ob2 reader will say or at least point in me in the right direction.

 

I'm interested in other members past experiences or repair advice not your two cents. most of the repairs I've made were do to excessive ware or a failed sensor. others I justified as tune up parts.

 

Well, anyone's response is going to be their two cents. So i guess you dont want anyone else answering either. Sensors don't get excessive wear nor do they all just fail like it seems your implying.

Still didn't answer where you got the sensors at. Which is a big deal. Not all sensors for these trucks are good to buy from parts stores. Some really need to be bought at the dealer.

With the v8, crossing two plug wires would cause a miss but still run well enough. It'll still run if you cross 4 as well.

Lastly, there's no reason to be an asshat just because you didn't like someone's answer. Its a common answer when someone lists a crap ton of parts they've replaced for no justified reason just to try and guess what's wrong.

Have you even bothered to try and do the key dance for codes? Did you even know you could do that with your truck?

Check your attitude and try again, and actually answer the questions others are going to ask anyways.

 

I really don't feel the need to defend myself to you but I'll humor myself anyways. The timing chain and distributor drive gear were excessively worn. I confirmed both of these problems before taking it apart. The intake was also confirmed bad and repaired. I replaced the idle air valve because it was not functioning. And the 02 sensor was replaced with new exhaust. I am also well aware of how to check codes for obd1 Dodge. Thanks for your concern however if you do not have a constructive response for my question then please ignore my thread.

 

Check the Throttle valve cable is adjusted properly at the Throttle body. You can get a lot of RPM change at idle with minor adjustment there. As for elec parts the crank sensor and coil are probably due for a change out too. This link is for a Ram but the principle is the same http://www.bionicdodge.com/Download/...Adjustment.pdf

 

Just FYI, you can add him to your ignore list if ya don't want to see what he writes.

Did you test the crank sensor?
Coolant temperature sensor? These trucks use a separate temp sending unit for the gauge and a dedicated temp sensor for the PCM so unfortunately a working or non-working gauge means jack for diagnosis. Facing the truck, the temp sensor (PCM) is to the left of the thermostat housing. The temp sending unit (gauge) is to the right of the thermostat housing.

You've replaced a crapton of parts already, I think you're getting close to suspecting a bad PCM. But not quite yet. Two things come immediately to my mind. First, these trucks are infamous for a corroding three wire splice which powers the computer, fuel pump and Ignition coil. Even if it's not the problem, it's a good idea to check it. I did mine for preventative maintenance and it was somewhat corroded along with 2 inches of the main wire itself, but others have found the splice basically disintegrated. Symptoms can start subtly and include random backfires. Splice is #115 and there are numerous posts on all the Dakota forums about it.

That said, if your truck is running rough ALL the time consistently, it's probably not the corroded splice. Sounds like it could be a bad cat but I'm assuming you replaced or deleted that with the new exhaust as well?

After all that I'd be closer to suspecting a bad PCM. I don't think it's super common with these trucks but it certainly happens.

Apologies if I'm saying things you already know, good luck.

 

Thanks for the technical feedback. This is the kind of response I was looking for. The emissions has long since been removed from this truck so no cats. The coil is an MSD coil that was with the truck so it's not original but I have no idea if these are problematic or not. Your mentioning of the crank sensor has reminded me that was also replaced when I converted the truck to a 5 speed however this was an eBay special ( a lot cheaper than Napa or O'Reilly) so this part could be suspect. I'm not sure if the PCM is original to the truck or not it looked pretty clean compared to everything else under the hood before cleaned everything up. Is there a way to test the crank sensor?

 

Well gee, its a shame someone didn't ask you twice where you bought the sensors at. Start by buying one from mopar. Aftermarket sensors have proven problematic like your complaining about. If you would have just answered that from the first time I asked could have saved a lot of trouble. But for whatever reason you had to get all butt hurt so whatever floats your boat.

 

So has the truck had this problem since you owned it? Or did it start after the 5-speed swap?

As far as I know it is pretty much impossible to detect a bad PCM using standard tools, but maybe I'm wrong. From what I gather, people replace the PCM when they have exhausted all the other options they can think of.

Far as testing the crank sensor, I've done it with a multimeter but I'm kind of a doofus with electronics compared to guys like this, so I'll not even try to explain it: