# 87 pathfinder vg30i high idle and surging.



## robert1987 (Jan 15, 2013)

vg30i motor with 230,000 on it. its my second one. good rigs.. since the day i bought it always has surged when warming up. around 1,000-2,100, and after surging has hi idle around 1,300. now lately it has been doing it more when warmed up, and not in gear. other day it broke down on me. had to tow it. had spark, had fuel, seemed like some sort of sensor. checked the ecu. it threw a number 13 code. radiator sensor. then it started right up like nothing ever happend. ive checked for vacume leaks, cleaned the tbi. new wires, plugs, filters. also sometimes when its warmed up , and surging. ill turn the heater on and it will make it stop, and starts again when is turned off. i looked online, and have found some helpful info, but not what i need to know. if anyone can help me i would be very grateful. thanks


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## SPEEDO (Jun 9, 2003)

high idle, I was going to say "thermo element" (top of throttle body) but also sounds like its hunting, have you checked the air flow meter (hot wire module, black box, also on the upper throttle body) a couple of thoughts anyway


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## smj999smj (Jan 1, 2006)

When you mentioned turning on the heater affecting it, the thermo-element ( aka wax element ) also came to my mind. I've seen a few thermo elements fail but I've also seen the coolant hose that run to the thermo element housing get clogged or restricted and cause improper operation.


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## robert1987 (Jan 15, 2013)

sorry i should have said. When the motor is cold the heater does not change anything. only when its warmed up. over the months it has been getting worse. all my vacuum lines seem to be fine. its not the egr valve. because it does not work while idling. my cpu never threw a code for the throttle position sensor, and the wax element wouldn't change anything, because it surges no matter what temp. (more when its cold). so i dont think thats it. right?


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## smj999smj (Jan 1, 2006)

Surging usually occurs when an engine is lean...so one would check for vacuum leaks, bad O2 sensor, etc. Bad wax could play a part in the high idle. Just look at it when it's cold and start the engine and see if it retracts as it warmsa up.


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## robert1987 (Jan 15, 2013)

i figured out that the surging was caused by a bad cap and rotor. rotor was a pain in the ass to get off the shaft. my truck broke down again, and then started back up. the ecu threw a number eleven code. (crankshaft angel sensor). replaced that. so far so good. still the motor idles way to hi.


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## rmbhs (Dec 30, 2006)

did you resolve the surging problem ? my 89 vg30i is behaving exactly the way yours is. I have no codes and it never stalls. Just the surging and high idle.


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## rmbhs (Dec 30, 2006)

*surging idle fixed*

Here is a post I copied from another site. I used this information to repair my surging idle problem with my 89 pathfinder : I have 2001 Frontier 2WD with the 2.4L engine. About a year and a half ago, I started having idle issues and went through about everything I could find to correct it. Over the course of several months, I tried new vacuum lines, IACV, PCV, plugs, wires, thermal plunger, and MAF sensor. While the problem got a little better, I eventually took it to the dealer to figure out what exactly was wrong. I was told a thermal switch in the egr system was bad, the intake manifold needed to be removed and cleaned, and even though they knew I had replaced the MAF sensor once, they also suspected that the one I installed might have problems. Anyway, they call me 3 days later and tell me it is ready to go. When I arrive, they had it warmed up and ready to go. The next morning, when its cold, I am surprised to see the engine idle to nearly 2200rpm initially. When I drive it, the idle surges for about the first 3 miles of driving, but then it seemed to settle down and run good. I did notice that even after it warmed up, the idle was about 1000rpm. Doing a search on this forum and several others, that seemed to be a common complaint with many Frontiers. I figured I would give it some time, before calling the dealer that worked on it. I was really hoping I could avoid this, since it such a hassle for my wife when I do not have my truck and I have to use her car. I looked everything over when it was warmed up, looking for anything obvious that could cause a high idle. Then I decided to look at it while it was cold and noticed something interesting, the fast idle cam has two marks where an arm connected to the TPS should be when the engine is hot or cold. I had looked at this when the engine was warm and the "hot" mark was aligned spot on. With a cold engine however, the "cold" mark was about 1/8" from the roller on the TPS arm. Figuring I could always move it back, I adjusted the fast idle cam "cold" mark to be aligned with the roller on the TPS arm. I started it up, the engine idled to 1800rpm, dropped to about 1200rpm and after warming up for several minutes, dropped to about 700rpm. And on top of all that, the surging went away. Of course the fast idle cam "hot" mark is now slightly off, but the truck is now running like new.


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