Surging headache
I have a stock 1995 Dodge Ram 1500, 318,2wd.. After a tune up I drove it and it started surging when maintaining speed. And it wont idle. The dealer said it would idle if unplug pvc, and the iac might need cleanig or replaced. I removed, striped, and cleaned throttle body. I put new iac, pvc, and crankcase breather. It does start easier and runs smoother. But still bucks and surges, and wont idle after it runs for a minute. What else can i do?
You stated that it did not have this problem until after you tuned the engine…..
Did you just replace spark plugs or did you do more? Please list all parts replaced.
replaced plugs, wires, cap, rotor. dealer and the firestone tech both said that i didn’t screw up anything. all was checked by both.
If it didn’t do it before you tuned it and it immediately did it after… but anyway, lets pretend this just happened out of the blue. Lets try to simplify and narrow down some causes to your symptoms.
Symptom 1. – Won’t Idle unless a vacuum leak is induced
Symptom 2. – Surges while driving
First thing I would do is check for codes. Since this is a 1995 OBD I it can be done without a Scantool. And the instructions and codes can be found right here on this site: http://freeautomechanic.com/diagnostictroblecodes8.html
I suspect a rich rich fuel condition as when adding a vacuum leak (more air) it idles and a rich fuel condition would also cause the O2 Sensors to back off the fuel delivery because it thinks it is getting to much gas already and it would cause it to not idle and surge while driving.
Let me know what codes come up and we will work further.
no codes found by either tech. not even on old one. thats what really bothers me, have worked and schooled in fuel injection, but was some time ago, i was thinking either one or both o2 sensors or the map sensor. what do you think?
I do not think the O2 Sensors are bad, but its possible. You might want to try unplugging the O2 Sensors, this would set a code and also default the computers parameters for fuel trim…. would be a good test.
ok, didn’t think of it, will do it sunday and drop a line sunday afternoon and let you know. thanks
ok, i unplugged the o2 sensor and it made a big difference… but…. still stumbles a little now and then when maintaining any speed. it’s not a constant stumble, it’s often, and really bugging me.
Sounds like a shortage of fuel then. Might as well put a new O2 Sensor in it and see how she does. It won’t run right with it unplugged but it lets you know that it is making a difference. Still might need to replace the map sensor though.
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