89' w100

I have replaced the fuel filter and gave it a tune up.

The truck idles fine but, when i push the acc. pedal it starts to stall then dies. It does start right back up and idles fine again. I dont hear a sissing noise so Im thinking its an electrical issue. A guy at work said its because its idling too low.

Would a obd scanner show what the problem is?

 

Did you set the timing? If so did you unplug the temp sensor,then set the timing? 10deg if I remember right. An OBD scanner that reads datareal time as opposed to a 'code reader' will definately help. Chk the TPS,it is like the acc. pump,and vacuum advance on a carbed mtr. A dead Map sensor will screw things up too.

 

The truck idles fine and doesnt backfire so I dont think the timing is off.
I was planning on purchasing some shop equimpment, what type of timing light would I need in order to check timing on that dodge?? It has that electronic spark advance.
Would a obd scanner tell me if the map sensor is malfunctioning????

 

Being OBDI, It should tell you if the sensor is bad, it'll read out of range or something like that.

 

but if it isnt flashing a check engine light then doesnt that mean then what will a reader tell you?

 

OK let's start with the basics.
Check fuel press. 12-13 psi steady when you open the throttle.
Chk inj. at idle for spray pattern. Cone shaped,no streams,equal flow.Snap throttleand watch pattern. Should see momentary increase.

Now then, while opening the throttle you should hear/see the inj. pulse width change. [clicking sound should speed up,more fuel] Chk TPS center wire,key on,engine off, Greater than 200 millivolts throttle closed, to around 4.8v @ WOT with smooth increase. If not,chk. for 5v supply to TPS.

A scan tool such as Snap-on etc. let's you see what the computer sees. The OBD 1 wasn't the greatest on self diagnostics,may or may not give you a chk. engine light.
Any timing light will work.Disconnect temp sensor,start mtr.,chk timing.

Yes it's entirely possible the vac port to the MAP sensor is plugged up. The MAP reads load or vacuum.Be worth a look. If it's not, hook a handvac pump to the MAP,pull about 18' vac. Start the mtr and slowly bleed the vac off. The idle should go to hell. [rich]

Also disconnect the EGR valve, see if it changes anything.

One question,does it do this cold as well as warmed up? When the mtr is cold the computer is in open loop till it warms up, then goes to closed loop.Doesn't add the o2 sensor into the mix until warm. Also you will hear the inj pulse width change rich/lean when it's reading the o2, even at idle. A dead o2 will usually have a constant voltage,causing either an always rich or always lean condition.

Under what circumstances did it start acting up?

 

I was reading another post and I have an idea. Since im not getting an error code, is it possible that the throttle body is just dirty and some of the ports where the sensors mount are just dirty and need some carb. cleaner and or a can b-12 or seafoam ran through it??? Would a bad o2 sensor cause some problems??

 

Since you say you are not getting a code does that mean you did the on...off...on...off...on with the ignition?

 

correct

 

I would have to say yes that it does stall when its cold and warm.

I remember going to a gas station and it died. I dont drive the truck much to know though since its not inspected.

Should I start by cleaning the throttle body and see if that solves anything?? then proceed.