horrible s50 idle, please read, I am sick of this

[rede30]

I changed out my harness because I had a wire melt and take out some wires with it. I don't know for sure why I had a wire melt but I suspect I had a power wire grounded to the body from my gauge pod. When this first happened, or while it was happening, my motor started to do idle around 2 and then drop to 1 and then go to two again- and so on.

So a week or two ago I fired up my s50 after replacing the engine harness and my idle is going crazy. I messed around with things when I had some spare time but didn't really do anything. I even drove a few yards with the icv unplugged and it ran pretty good for the very short time it was driven.

now, after firing the motor and plugging and unplugging things, with the icv plugged in or not it surges from 1rpm-2rpm-1rpm-2rpm and so on.

I changed out the icv and I have the same probelms.

MAF?

[Farbin Kaiber]

Did you by chance crack any vac lines when pulling the harness? I assume you pulled the Manifold to get the connectors under there, What about IM gaskets, reuse, or, new?

[rede30]

Did you by chance crack any vac lines when pulling the harness? I assume you pulled the Manifold to get the connectors under there, What about IM gaskets, reuse, or, new?

I checked all my lines after I pulled the IM, I am feeling good about no vac leaks. I reused the IM gaskets, they are only about 2 years old with <3000 miles on them. I fell pretty good about those, also.

the thing is, the surging was happening while my wires were melting.

[Farbin Kaiber]

Any sensor side wiring damaged and shorting to block/engine? Did you spec out all the sensors?

[rede30]

Any sensor side wiring damaged and shorting to block/engine? Did you spec out all the sensors?

I checked the wires on the sensor sides. I didn't check the sensors themselves. Any in particular that could mess with idle? I didn't trace the cps wire, I should check that.

[Farbin Kaiber]

That was the sensor I was thinking about.

[rede30]

my ohms are in spec on my cps and the wire is good.

[flyboyx]

get yourself a peake scanner. Reset the fault codes in the ecu. Presto! I am 95% sure that will take care of it. If not, then you will have the code or codes left to work on a solution

[rede30]

I just pulled codes. I got a A1, control unit supply. looks like this code comes from disconnecting the battery and such, at least this is the most common reason. Any other ideas? It just keeps surging from 1-2-1-2 rpm.

[rede30]

As I drive and ponder...there has to be a vac leak.

[M-technik-3]

Is your maf damaged? Have you disconnected that to see if it idles smoothly with it disconnected? Check this it take two minutes or less.

[rede30]

I unplugged the MAF and it still runs rough. My intake sounds like its sucking extra hard, its very loud.

[Farbin Kaiber]

Did you by chance crack any vac lines when pulling the harness? I assume you pulled the Manifold to get the connectors under there, What about IM gaskets, reuse, or, new?

As I drive and ponder...there has to be a vac leak.

Time for a can of carb cleaner.

[M-technik-3]

Thinking as mentioned above and other places you have an intake leak. Aka unmetered air.

[rede30]

I pulled the IM off today to see if there was a pinched wire or something messing with the seal, there was not. I looked over the hoses and seals again and they all look brand new.

I ran the motor a little bit more today and even drove the car 1/2 mile. It seems to idle worse when warm. It didn't even want to start and if it did fire up it would just die. If given some gas it would get into the normal 1-2 rpm surging.

I am about ready to order new sensors, all of them.

Could this problem be my DME? or aftermarket chip? What about a relay? I say relay because the wire that melted and caused all this was the little green/violet one that comes off the fuel/o2 relay (i forget what one is the green one.)