so, my durango randomly stalled, until the day stalled and did not work anymore, so i had a p0601 code and a random p0108

the last 2 stalls, my fuel pump stopped working, and worked again when cold

durango 2001 4.7

so far

changed pcm (for p0601)
then new pcm on board and stalled again after 2 mins , so
changed fuel pump

checked hoses, changed canister hoses and checked for good canister, all went good, checked my sensors, got 5 v on the feeding of the sensors, and cleaned all my rusted grounds, found some discrepancies on my tps and map, but couldnt find the right specs so plug my pcm and battery and started

it lived again and went for a test ride, ..................... idle goes so low(450 to 550)that want to stall when i stop (but only when i stop, cause if its walking and take my foot from gas, engine is still smooth) ............. ok im getting tired

so after reading and watching lots of videos on how to test map tps and iac (mos common culprit for this cases i think) i found that it supposed to have 1.5 to 2.1 v on the signal of the map sensor, ............. i have 0.90 so i read that if you dissconnect the MAP , your idle will be smooth but affects fuel economy, but is a way to test the map . so i dissconnected the map and started engine and .................. THE ENGINE START SURGING LIKE CRAZY (between 500 and 750rpm ), idle goes up and down at a pendulum rhythm so i thought maybe is the iac that cant stabilize so i disconnected the iac while the engine was on and surging didnt stop, so i was like , maybe the tps is indeed bad , checked the signal voltage and it was stable, no movement at all in the voltage, so i pulled off, surging was so bad that engine stalled afer some seconds


disconnected battery and put all together again, put battery and started engine, again stable but idle went to 500 and fighting to keep awake

after new pcm and new pump, where should i look for this? map? iac? tps? something else? ........ injectors?

is it normal that engines surges like that if map sensor is disconnected, i read in several post that idle supposed to go smooth , not surges, why my engine went like that?

throttle body is clean, i dont have broken hoses on the evap system and new pcv hoses

is this a symptom of a plenum gasket? or what is this symptom points to?

help is really appreciated

 

Weak battery/battery connections (also battery cables at the PDC) and the IAC would be the two most common causes for stalling at idle. Give the battery connections and cables a good cleaning with a wirebrush and see if that helps.

 

No plenum gasket on that engine.

+1 that guy!


1. Remove the throttle body from the engine and thoroughly clean every port and remove any electronics. Use 2 bottles of Throttle Body cleaner and an old tooth brush, whatever is needed. Look closely where the IAC goes into the TB, they like to get filthy there.

2.Clean all battery terminals and connections, also clean block negative.

3. IAC is bad or dirty, again check ports in the TB and ensure it is clean.

4. TPS should start around .5 v and go to 4.5 at WOT. During measurement voltage to ground increase should be nice and smooth. If it jumps or blacks out it's bad.

5. What does a MAP Sensor do?
The MAP sensor converts engine vacuum/manifold pressure to an electrical signal so the computer knows how much load the engine is under. This data is the basis for fuel delivery and timing control. Unplugging it can do a lot of things as you can see. Probably not a good idea when diagnosing.

6. Replace spark plugs with the cheap Copper Champion OEM plugs and gap to .040

 

i did clean the battery coonections and wires before i connected the pcm , the grounds on the body, on the engine, and the positive that goes to the fuses box

my battery is an optima and is still in good shape i did test the battery and alternator and it passed the test under full load

when engine started to surge (with map disconnected) , i thought it was the iac, and disconnecting it didnt affect anything, i did the same later with map connected but idle still was down, going to change spark plugs (i have a ngk that some forums recommend) and see if that helps but i dont think so, they are almost new

when i watch closely even with map connected it surges but really low, but watching the needle it goes up and down but it cannot be noticed if i dont watch the needle mmmmm i hope somebody can give some more advice, thanks

im thinking in throw in some crc engine cleaner (the seafoam alike) and see if that helps im not sure what to do right now

 

If you don't notice it unless you are looking at the tach, maybe the tach is going bad?

 

Try a different battery, just because it doesn't fail a load test doesn't mean it isn't bad.

Other than that I would again lead to the IAC, and make sure that TB is fully cleaned out including IAC port.

 

Like Hydra said, definitely try the battery. Every bit of research I've done for batteries points out that Optima is not a good one for vehicles, it is better for sound systems. When I go to CO, I work with heavy equipment along with boats and smaller equipment. Every battery we buy is Deka. They are in between Optima and other brands price wise, but can withstand way more of a beating than any other. Along with the fact that Optimas do not charge as efficiently. Dirt and grime anywhere can lead to a problem in an engine. I've had your problem before on a 2001 4.7, the IAC was filthy. What else helped was that I found a decent shop who did a full fuel system cleaning/de-carbonizing, truck ran beautiful after that.

 

I know when we disconnected or replace the PCM or any other modules, we had to reset all the values with a scanner in the PCM. But I also look at the TPS or the Idle speed motor. If you had a valve leak, you would have a high Idle.

 

**UPDATE

mmm ok, so i had my d for some days and the idle still is low on 550 range, when im stoping idle suddelnly drops and my engine feels like a sudden braking, no engine light and no codes so far, i tested with another battery , my neighbor bought a new battery a month ago, and is compatible with mine so i tested without any change

so i tested my voltages and found some bad stuff on MAP and other that im not sure on TPS

i have good 5v from pcm, and good ground (clean all of my grounds and now i dont have any resistance like before)

so testing signal lines
MAP
this is a big problem i think, i tested my map, and when there is no key it have readings, i saw somewhere that a normal map should be 1.5-2.1v on idle and 4.5-5.0 on full open throttle ---- i live at 2200 meters over sea level, so if im right it should be closer to 2.1 than 1.5 cause the higher it gets the lower ambient pressure (maybe im wrong and only affects with engine off) anyway

so my readings are this
map
no key........... 0.33v im not sure if there must be voltage when all is off
switch open ... 3.79v i think it should be above 4.5
idle ................1.10-1.20v it is not stable, it fluctuate between 1.10 to 1.20 randomly (and i think it should be above 1.5 as i read on internet)

the problem start here, when i open the throttle, map goes all over the place, voltage supposed to go up, but instead it GOES DOWN, start on average 1.15 and as i open the throttle, goes 0.9 - 0.8 - 1.4 - 0.8 - 1.6 - 0.9, when i reach 4000 rpm it still on 0.8 0.9 range, and smell to bad combustion, so i stopped testing

i tested wires to pcm and it have good continuity, no resistance and no broken wires, but there is resistance between voltage and ground wires, and it comes from both MAP and TPS,cause when disconnected, all my wires are clean of resistance between wires, im not sure if this is normal

i think this is a bad map sensor if i understand, or can other problem besides a bad map sensor can cause this symptom?

TPS
now,as i said on other thread, my tps had a weird resistance that im not sure if it should be like that between voltage pin and ground pin, and when connected affects all the wiring on all sensors, not sure if its normal (my first durango and car)
multimeter on 20k ohms
the manual says
1 K7 18OR 5VOLT SUPPLY
2 K22 18OR/DB (JTEC) THROTTLE POSITION SENSOR SIGNAL
3 K4 18BK/LB SENSOR GROUND

between -------- (ohms)
1-2 ..... 4.86 closed to 0.23 full open
1-3 ..... 4.94 closed......4.94 full open (no change) <--- im not sure if this resistance should be there and when connected this goes to all my sensors, all sensors have resistance between ground and voltage when tps is connected, is this normal?
2-3 ..... 0.38 closed to 5.04 full open

so, now i tested on volts, but voltages are almost normal, goes up and down without jumps or losses, still is not normal i think, probably my tps is faulty or little shorted im not sure.

tps
no key................ 0.05/6/7 .... is not stable it moves up and down randomly
switch open ........ 0.65/6/7.... again is not stable it moves randomly
idle..................... 0.69/70..... over again is not stable
fully open ........... 3.82 ..........(tested only with engine off) with engine on, only tested like half of it goes up nice until it reach 1.8vno further test cause it smells really bad maybe cause the map problem

movement on voltage is really small, ´cause its 0.0x volts, is really minimal, but as i open the throttle goes up really nice, and there is not any loss or jumps, but it goes all up, and when is fully open it reads 3.82, it doesn't go further
im not sure but i think voltages are not right, but im not sure i dont have the specs and my manual does not have them, i remember that hydra said on other thread that it should be a minimum of 0.5 and fully open to 4.5v but i think was on a ram thread, so im not sure

im going to buy a new map, but what do you think about the tps, i ask because where i live, both MOPAR tps and map cost 100 bucks each so they are expensive (cant buy on ebay) only the tps is cheaper at 50 bucks on autozone a duralast one, but im not sure how good that brand is on electronics (i bought other stuff and is really good solid brand but never electronics)


as always help is appreciated

 

i wouldnt worry about the idle 500-600rpms is pretty normal for these trucks when warmed up.

That said iw ould start w/ the MAP sensor, if its not giving consistent readings thats not right, as for the TPS if it is giving smooth steady readings as the throttle valve opens the computer can and will adjust to it so i would hold off on that one (not saying its ok, just saying the MAP is a bigger issue right now)

remember before changing the sensor to disconnect the battery