I'm having some trouble with a Durango and I'm hoping y'all might have some suggestions. Two problems recently which I think are unrelated, but I'll list them both in case someone smarter than me sees a connection. A couple months back the truck started idling erratically, revving up randomly when sitting. That slowly progressed to a surging around town, then surging on the highway. No check engine light and nothing obviously wrong. Then one day we were on our way to vacation and the thing just went totally to shit, didn't want to run, and the check engine light came on. Stopped at AutoZone to have the code read. It came back as a bad TPS, replaced it in their parking lot, and everything was right back to normal. So that's solved, at least I think so. Drove the truck all around for a few days, both in-town and highway, no problem. Three days later I'm pulling into a Burger King parking lot and it just dies like it ran out of gas. The gauge is still showing 1/8-1/4 tank but I call someone to bring a can anyway. Pour in a couple of gallons, it starts right up and drives over to the gas station. It's all good for another few days of frequent driving (again, both in-town and highway). Then my wife gets in, starts it up, and tries to back out of the driveway, and it dies. A little while later it starts right up and does fine for another week or two. Then it dies on her again sitting at a stop sign. It takes a few tries to get it refired, but once she gets it going it drives home just fine and hasn't acted up again for a few days. It always just dies at or near idle without any fanfare, just like it's running out of gas. I checked the fuel pressure to see how the pump was working and everything was fine, although since it's an intermittent problem it may just have not been acting up that day. If it's a fuel filter I would have expected problems at speed or when accelerating, not at idle. There's no check engine light. So I'm kind of at a loss. Could this be related to the new TPS? What else should I be looking at? I hate intermittent problems!! :dog
Battery terminals clean, tight and coated with dielectric grease? Engine/frame ground checked also? Fuel pump giving up the ghost? It usually starts making strange noises. I just had a lean bank code thrown at me, removed the MAF sensor and cleaned it. Found the crank breather hose came off between the MAF and throttle body.
When it dies and won't immediately restart, you need to take the time to determine if it's loosing fuel pressure. I don't think there's a filter in that system, could be wrong if it's an early model. Will it stay running if you two-foot it (as in never dies off idle?) TPS values are often referenced against MAF values to determine component failure. Poor MAF readings could have tripped a TPS code but it's rare. MAF cleaning is always a good idea. Cleaning the IAC motor and throttle plate(s) often improves idle as well. If you have a buddy with a scan tool, they can reset the min idle and TPS values, though it's not likely the culprit. If it's been a while, have a garage run it on a Motorvac or similar machine to clean out the intake and combustion chambers. I found that has a positive effect most of the time too. Let us know what you figured out in the end please!
What year and what engine? How many miles? Our 03 RT had stalling problems in warmer weather that was cured by replacing the ECM on the passenger wheelarch. If you online search,this is a not uncommon problem,especially if the truck is at or over 100k miles. Rebulit and tested units can be found on eBay,etc for under $200 as opposed to $1200 from dealer. Others report that crank sensor was also problematic. Ours is running fine after I replaced the ECM. Issue seems to be heat stress to the ECM over time and it's positioning in a poorly ventilated area. Also check and clean the three multipin connectors to the unit. If you have a similar situation,year next time it quits check too see if there is a "no bus"warning on the message panel above your left knee and near headlight switch.this is telltale for an ECM failure. JR356
The truck is a 2000 model with the 4.7L engine. It sounds like the mass airflow sensor is the place to start for sure. I've never noticed any warnings in the area you're talking about, but to be honest I don't guess I've ever thought to look there. I'll definitely check that out if (when) it happens again. So I'm guessing Google will be my friend here, but are there any special procedures to cleaning the MAF sensor?
If you have your own tools (sounds like you do), it sounds like you need to bite the bullet and buy a scan tool. Otherwise a lot of what you will be doing is simply guessing.
But no check engine light==no codes, right? At least that's always been my assumption. If the light is on I just bebop over to the AutoZone for a free code scan.
Now I've found a couple of places on Dodge forums where people are saying the 4.7L doesn't have a mass airflow sensor. I've been crawling all over the thing and can't find one, or a cable running towards one. Am I missing something? Dodgepartsonline.com shows a MAP sensor and an air intake temp sensor but no MAF. I did find a couple of guys with similar symptoms that they blamed on a dirty IAC (some kind of idle control). I've cleaned it up and hopefully that will solve the problem.
Dodge does not use a mass air flow sensor. the system is called Speed density....Speed Density systems accept input from sensors that measure engine speed (in rpm) and load (manifold vacuum in kPa), then the computer calculates airflow requirements by referring to a much larger preprogrammed lookup table, a map of thousands of values that equates to the engine's volumetric efficiency (VE) under varying conditions of throttle position and engine speed. Engine rpm is provided via a tach signal from the crankshaft position sensor, while vacuum is transmitted via an intake manifold-mounted Manifold Air Pressure (MAP) sensor. Since air density changes with air temperature and altitude, an intake manifold-mounted tempature sensor, and barometric pressure sensor is also used. the fuel Trim is kept in check by the up-stream O2 sensors, the reading from these in closed loop operation can change the fuel delivery strategy. This system is very reliable. the Idle Air control valve and passage ways on a 4.7 ltr are susceptable to carbon build up. also there is a revised Idle air contol motor available. also build up on the back side of the throttle plate can restrict air flow. this all needs to be cleaned by removal of the throttle body and cleaning the ports with a cleaner. DO NOT SPRAY cleaner into the engine while running without the correct metering device as the chemical COULD combust in the plastic manifold and split the bottom off. The easist way for the oil/carbon to enter the system is through a poorly operating PCV system. if there is oil behind the throttle plate, check the pvc system. If it dies when the throttle is lifted at low speed, then replacement of the Idle air control valve and cleaning the throttle body will in most cases fix the issue.
This is what I'd look at. A voltmeter in the cab is real nice to have - I've got one on my two-way that's hooked straight to the battery with 4AWG wire under the back seat. There's some that plug into the cig. lighter too. On the battery in my truck there's a collar on the battery post itself... ...in other words, there's the post on the battery, over that is a collar, and the battery cable on the truck clamps over that collar. Stupid design. But, just pulling the cable off and cleaning the "terminal" (outside of the collar) won't always do it-- there's corrosion between the collar and the battery terminal. Car parts stores have battery brushes that look a little like a 3" tall fleshlight with wire bristles on the inside. Those work well, that'll set you back about $2.
Remove and clean the throttle and IAC (Idle Air Control valve) You may need to relearn the idle strategy (Scan tool required) More or less it is the table that the ECM uses to control idle speed. As the throttle & IAC get dirty + the general condition of the engine+ A/C load + in gear + what not, the ECM adjusts its adaptive strategy to "learn" what it needs to control idle speed for that given environment. Resetting this table is a good idea after having any repairs completed that may have an effect on idle speed.
A little over a week since I cleaned the IAC and no more dying at idle since then. The problem was intermittent enough that I don't want to declare it cured quite yet, but it's looking good. The truck does still idle ever-so-slightly roughly. The next time I have an afternoon to kill I'll take Blu and Zoomy's advice and pull off the throttle body for a thorough scrubbin'.
My Ford truck had failing IAC. Sounds similar to your problems. Mine would start then would not idle. Hope you solved the problem. I replaced mine as I wanted my truck reliable.
UPDATE: The problem seemed to go away for a while after I cleaned the IAC valve, but then it came back and started to get worse. I replaced the IAC valve today ($80). Hopefully that will fix it for good.
