1990 3.9L stalls when comming to a stop
#1
1990 3.9L stalls when comming to a stop
my 1990 dodge dakota is sitting around 170k miles and runs perfect down the road. The problem of it stalling only happen when I am comming to a stop, some times it will idle rough, act as if it is going to die then surge to regain idle... or sometimes it just plain out dies. Im pretty much posting because ive exhausted a lot of my money and time trying to figure out what the problem could be. I have had it to 2 diffrent shops and the dealership look into it but no one knows whats wrong(altho they all charge me). This is a list of services and parts i have had replaced, If anyone out there has any reccomendations on what the problem could be I would be much appreciative.
Replaced--
Main computer
idle speed control motor
exhaust system
O2 sensor
distibutor cap & wires
Ignition coil
fuel injector(x2)
Air filter
tested by dealership--
EGR valve
fuel pump
As you can see ive gone through a number of options and im die'n to find someone, anyone that knows this make of truck well enough to maybe gone through or found this problem out before.
tx in advance,
Mifune.
Replaced--
Main computer
idle speed control motor
exhaust system
O2 sensor
distibutor cap & wires
Ignition coil
fuel injector(x2)
Air filter
tested by dealership--
EGR valve
fuel pump
As you can see ive gone through a number of options and im die'n to find someone, anyone that knows this make of truck well enough to maybe gone through or found this problem out before.
tx in advance,
Mifune.
#2
RE: 1990 3.9L stalls when comming to a stop
Since you have done more than the basics, here's a couple of other things to think about.
Worn timing chain and gears. Slack will cause a timing change.
Torque convertor lockup problem(if it's equipped with lockup TQ) If the torque convertor stays locked up at stop, the engine will act just like a stick shift when we forget the push in the clutch.
TPS sensor and/or VSS(Vehicle Speed/Distance Sensor) and there wiring connectors. The computer uses both of these signals to determine deceleration and idle modes. Once the computer sees these values he will adjust the idle speed control motor to keep the engine from stalling.
Are there any error codes being posted in the computer?
Worn timing chain and gears. Slack will cause a timing change.
Torque convertor lockup problem(if it's equipped with lockup TQ) If the torque convertor stays locked up at stop, the engine will act just like a stick shift when we forget the push in the clutch.
TPS sensor and/or VSS(Vehicle Speed/Distance Sensor) and there wiring connectors. The computer uses both of these signals to determine deceleration and idle modes. Once the computer sees these values he will adjust the idle speed control motor to keep the engine from stalling.
Are there any error codes being posted in the computer?
#3
#4
RE: 1990 3.9L stalls when comming to a stop
I have a 91 DD w/ the 3.9 that was doing the same thing. It would stall at stop signs or when I was doing heavy braking. I fixed my problem with a simple 16 penny nail. The problem is a clogged vaccum line on your throttle body. I can't remember which one it was in particular. I found the clog and pushed it out with a nail and I haven't had that problem since. I think it was on the front of the throttle body just to give you an idea of the line. I think my problem occured around 160k and I have over 194k on it and it still runs great. Good luck.
Undertaker420
Undertaker420
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#8
RE: 1990 3.9L stalls when comming to a stop
My problem ended up being a vacuum hose attached to my throttle body. I spend probably 2k dollars at all the shops and the dealership to have them tell me they couldnt figure it out... And then I found a hole in one of the vacuum hoses comming of the front of the throttle body and fixed it with 5cents worth of electrical tape... go figure. So I would say dont assume anyone has checked the small obvious things unless you check them yourself. Pull off you hoses one by one and inspect them for any holes or cracks, the hole on my hose was just under a 90degree bend in it so it was pretty hard to spot/notice. Your truck being a 95 could be something totaly diffrent but in my hanes manual, vacuum line problems are the top culprity for this symptom.
#9
RE: 1990 3.9L stalls when comming to a stop
Just a reply on my situation. It appears that removing the idle control valve and thoroughly cleaning it and the throttle body port that it bolts into did the trick. I also re-set the computer and drove it around for about 20 minutes before shutting the motor off.
Thanks for all the info. I should change my nick to notsoangrydakotaman lol.
All has been OK for a few weeks since doing this.
Thanks for all the info. I should change my nick to notsoangrydakotaman lol.
All has been OK for a few weeks since doing this.