89 Dodge Dakota, Surging, stalling, possible EGR, Fault code #34 My truck idles in park well, when I hit the gas lightly, it bogs, and looses power, then suddenly accelerates, then cycles back to low power, in a regular rhythm. If I hit the gas hard, it seems fine, but will not cruise at 20 mph, and often stalls when I hit the brakes. I have been chasing down codes. My first code scan, from an auto parts dealer, showed these codes: 12 memory to controller has been cleared within 50-100 engine starts, 24 throttle position sensor voltage high/low, 31 purge solenoid circuit, open or short detected, 32 egr solenoid circuit, open or short detected 34 ????speed control servo solenoid, open or short detected (Conflicting info reveals this could mean: models with EGR, EGR solenoid open or shorted ), 35 radiator fan control relay circuit, open or short detected 36 wastegate solenoid, open or short detected 52 running too rich I examined the wires, plugs and components of the ECU by taking it all apart. Found no problems, put it all back together, and I reset the computer. Next day I did a 20 mile test drive. It ran great for about ten miles. Probably getting up to temp, then started to chug, and surge again. This seems to be s symptom of EGR failure. I did a home code read, by turning the ignition three times, and got only three codes, 12 memory to controller has been cleared within 50-100 engine starts 34 ?????Cruise OR EGR? 55 end According to the error code #34, it should be the default reading for a vehicle that has no cruise control, which my truck does not have, but, according to another site, quote" 84 – 87 models with EGR, EGR solenoid open or shorted 1987 and later models: cruise control servo failure" My truck HAS an EGR. Here is a picture of it. http://images.oreillyauto.com/parts/img/large/bwd/egr1040_1.jpg I dis-assembled the plastic diaphragm, and found it full of carbon residue. Cleaned and Re-installed it. I tested the Throttle Position Sensor with a voltmeter, and it seems to be functioning properly. I found oil in the air cleaner where the crankcase vapors enter. Examined one spark plug, clean, tan deposits, and slight wear of the electrode. I have reset the computer again, and run the engine in place, while checking the vacuum system. I have not yet test driven it, since the reset, but I now only get two codes. #12 and #55, which are totally expected, and benign. I have ordered a new EGR already, and also a TPS, just in case, as that is what a couple of mechanics (who had not been able to work on it) recommended.

Need a faster answer?
If it smells like rotten eggs it's the cat (s).
Was this answer helpful?
Yes
No
Thank you for your feedback!