I am having an idle surge problem when the engine is cold especially. When I tap the throttle and let off the rpms go up and down over and over and the truck almost stalls. Could this be a problem with a torque converter, tune, or some sort of engine componet?

 

I asked about this over at NLOC there is a thread on it. But my only surged at Idle with no gas being given. There was about a 100 rpm difference. Check your TPS voltage. It appears that I was not the only one that this happens to.

Does this ? pertain to an Lightning?

 

I checked the tps it was a little high over 1.0, there was not much room for adjusting but i did slightly move it to lower by unscrewing the screws and rotating a tad. This did not help though. So I ended up getting a maf remote optimizer from pro-m. I richened the fuel up some on the low speed setting and this helped quite a bit. It appears this problem was due to my pro-m calib, b/c I also unplugged the mass air sensor and ran the truck and it did not do this. The truck ran a little crappy into the gas but at idle with the mass air sensor disconnected idle quality after tapping the gass improved. The remote optimizer I guess adjusted this.

 

IAC valve.. (idle air control).. basically a bypass of your throttle body.. allows more air to get to your engine when its cold.. take it off (2 bolts and a connector), clean it out with some carb cleaner and carefully push the spring up and down with a screw driver.. reinstall and try again.. its right here..

 

Wow.....where the hell are your clamps for the tubes connecting to the oil seperator.

 

I have already replaced the iac. Mine was so built up the spring would not get clean on the bottom. This was not the problem in this case though. it was due to the pro-m and larger injectors. The tps could not really be adjusted but richining up the fuel tables with the remote optimizer seemed to help. I will see in the morning if it does the same, it iis about 30 outside in ms now so we will see.

 

thats not my pic.. i have breathers..

 

I have been having the same problem for months and I can't get rid of it. I have changed the IAC two times...it helps a little but does not solve the problem.

 

i have the same problem and i have concluded my plugs are fowled, leading to a richer tune causing more gunk on the plug leading to poor spark, so im gonna replace the plugs and see what happens. just my .00002 and a half cents

 

not sure if thats it, I have brand new plugs and they are gaped just the way JDM told me to gap them, I had the problem before and after new plugs!

 

If changing your plugs does not help I would look at your tune and cold start tables. The pro-m seems to be pretty picky on cold start tables, and adjustment via a remote optimizer or tune may help. My problem may be partly due to my ngk tr-6 plugs being old but changing the fuel mix helped.

 

My TPS didn't have enough adjustment either. I drilled out the metal ferrels in the plastic. I had plenty of adjustment after that.

 

Problem is still there when truck is cold in the morning. When temp is up it is fine. It may be a little better, but it really ticks me off. I tried to lean the mixture out thinking it is too rich and practically blew the piston out of the engine, well not quite but it pinged at about 5300k pretty bad, I got out of throttle fast. Do you think it could be due to plugs or converter??

 

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