1992 2x4 dakota intermittant engine prob

Hi my name is Michael I'm trying to resolve a engine run problem.
The engine is a 3.9L Multi Port Fuel Injection System with 141,000 miles
I've been observing that randomly when I start the engine it sometimes
runs normal idle operation and then after say 2 - 3 minutes it will stall out.
from there it sputters and when attempting excelleration it will bog down and
or backfire. If light continous taps are performed on gas pedal I can maintain
a pulsing idle once my truck reachs normal operating temp i can either
accelerate as if kicking out a choke and it smooths out and can maintain Idle.

I notice that the problem is not completely resolved because even while
driveing randomly it will act up again like when slowing down near or below 35MPH or when coming to a Stop at intersections. Then I have to either shutdown and restart engine for on the fly switch to Neural Rev engine and try the kick it out process again.

I have already replaced the Fuel Filter, Throttle Position Sensor and Map Sensor.

I just started reading some post and some post are leading me to
the coolant temp sensor. I haven't read my codes recently.

I did have a O2 sensor issue and found that one wire on the pigtail
broke off due to corrosion I have replaced it along with a new exhaust
system cat, mufler and tail pipe all new.

With my description and if it could be the coolant sensor is there anyway
to test this or bypass the sensor to prove the fault is at the sensor?

I'm sort of mechanically inclined and electronically knowledgeable.

Thank You
For any help!

-Michael

I have a 93 Dakota (3.9L Manual Trans) with 100,000 miles that is acting the same. I had two fault codes stored (17 - engine too cold, too long; 34 - engine speed sensor fault). My temp gauge was reading low (in normal range, but lower than usual). I replaced the thermostat w/ 180° F; facory is 190° {found this out after I bought the 180° themostat}. This did not seam to change the gauge reading, the engine (per the gauge) was still running colder than usual (and in the normal range). I am also questioning the engine temperature sensor. I need to check it out; the service manual has a chart with the temperature vs resistance. However, there appears to be two temperature sensors, one for the gauge and one for the engine control module.
I have also replaced the IAC motor (did not help). The intake manifold temp sensor (did not help). I removed and cleaned the trottle body (no change).
I am am going to try two more items.
1) It was reported that the oil pump drive gear / distributor drive gear can wear out. Following is the check procedure:
The test procedure called for an inspection of the
rotational movement of the rotor tip. The total
movement should not exceed 3/16-inch. In this case,
the rotor moved 1/2-inch or more. This
indicated the oil pump drive gear, distributor
drive gear and bushing were worn.
2) I am going to investigate this speed sensor fault. I don't have cruise control which is what I thought this fault code was for...

I post any new findings...

John

I replaced my coolant temp sensor which sits to the right of the thermostat
and in proximatey to the Aircondition Pump.
It did not resolve my problem.
I also checked my Codes and I got a Code 12 and then the end code 55.
The Code 12 in my chiltons referes to Lost Memory Power?
Not sure what that means?
Also what was really weird was when I attempted to purchase the coolant sensor for my 1992 Dakota they gave me one that was listed
to fit a 6 cylinder or 4 cylinder from a 1991 - 1993
the one they gave me was too big for what I observed and in the book.

I had the parts store reference the next year when the part changed and found they had a listing for a 1994 "Only" part and it was the one I needed.

I think this was just a Murphy's Law fluke.

Anyway someone told me that they had a similar issue with another make of vehicle and was guided to have there injectors clean at a shop
this resolved there issues.

I'm feeling very confused at the moment not sure what approach should be next.

check the egr valve. If the valve is opening to early it will stumble and hesitate. Remember, the egr valve will not get vacum until the engine is up to temp, about 160. Simple test would be to disconnect the vacum line to the egr and plug the hose and see if it improves.

I checked the distributor and did not have excessive movement of the rotor. In the process of checking the coolant temp sensor, the connector end pulled out of the sensor; so it must be replaced now.
I will check the EGR once I replace the temp sensor. Thanks for the info...
Also, the 12 code just means the battery has been disconnected recently.

I checked the distributor and did not have excessive movement of the rotor. In the process of checking the coolant temp sensor, the connector end pulled out of the sensor; so it must be replaced now.
I will check the EGR once I replace the temp sensor. Thanks for the info...
Also, the 12 code just means the battery has been disconnected recently.

Funny you mentioned the Coolant Temp Connector pulling apart.
Mine did the exact same thing so I had to replace it anyway as well.

I will try checking my EGR as well.

Thanks for the Code 12 definition my Book doesn't say much about that Code.

Mike

check the egr valve. If the valve is opening to early it will stumble and hesitate. Remember, the egr valve will not get vacum until the engine is up to temp, about 160. Simple test would be to disconnect the vacum line to the egr and plug the hose and see if it improves.

I checked my EGR this definitely is my problem I also found that the
EGR sensor was completely clogged on it's inlet line which connects to the EGR valve.

I took a drill bit and cleared the airway that resolved my issue.

I finally was able to swap out the engine temperature sensor this past weekend (good thing my truck is a spare vehicle). This was my problem. Once it was replaced, engine performance was back to normal!
My engine temperature is still reading on the cooler side of normal (per the gage); probably related to the 180°F thermostat installed vs the factory 190°F thermostat.