[pktaske]

Put in a K&N CAI and Pacesetter exhaust over the weekend...when car is coming to a stop, every few seconds the tach drops down like it's going to stall. When driving at any speed, all feels well (no loss in power, chugging, etc).

Is an adjustment to throttle or VRIS usually required after doing such a job?

'93 LS

 

[haiyter]

did you connect the maf?

 

[agiatrix]

did you connect the maf?

If he has an LS, he has a VAF.
If the VAF wasn't connected, the car would not drive.
Could also be the ECU "relearning" the new fuel/air ratios... since more air is now being introduced into the system.
Could also be a minor leak of some sort.
- Anyone feel free to correct me if I am wrong, just a guess here.

 

[wpendl1]

There is not a learning curve for a CAI or exhasut. The A/F ration is predeterminied in the ECU. YOu give it more air, it gives more fuel based on air temp, volume, and readings from o2 sensors.

Sounds like you left off a vacuum line. Maybe one that goes to back of the elbow. There should be two. One small one, one big one. The small one will take the place of the hose that went to the stock air box. You may have to cut it to shorten it. The other one comes from the t in the back of the engine, part of the crank case ventilation...

 

[agiatrix]

There is not a learning curve for a CAI or exhasut...

I say this because same thing happened to me, First I put in a CAI...few months later a Borla...then finally Hot shot headers....
After a few days of driving it stopped doing that

 

[pktaske]

Problem seems to get better as the engine warms up...but it's still there...at a stop light/sign, eventually after about 5-10 secs, its drops from ~600 to~200 and then back up...runs smooth a bit...then does it again.

 

[RevZempoe]

I would definitely check a vacuum leak. Did you attach the vacuum hose to the intake?

 

[Fastest95PGT]

Maybe you forgot to hook a vacuum line back up. (damn Rev, you beat me to it)

K&N doesn't have a CAI that I'm aware of... so did this CAI have the TB/VAF intake elbow included?.. or does it just have the downpipe from the VAF to filter. If it didn't include the TB/VAF elbow, check to make sure you didn't crack your stock TB/VAF elbow in the rear which could cause an abnormal idle after warmup as well as a few other symptoms.

 

[killthelights]

where do you connect the line coming off of your intake too? i installed a short ram and mine is idling kinda funny, may just need to be adjusted but i put a nipple over the stem on my new intake because i could not find where the hose plugs into. There was a stem on my stock air box but no hose in it

 

[Fastest95PGT]

The only hose which connected to the stock airbox goes to the EGR system. It is to vent something (I forget what).

You can just leave it hanging in the bay somewhere, it shouldn't cause any problems.

 

[wpendl1]

Yup, you got it. It is the vent to the EGR solinoid. It connects to one of the two metal lines just under the throttle body, the metal line goes around the back, then another rubber hose goes down to the vent side of the EGR solinoid to vent the vacuum on the EGR solinoid. It's kind of missleading, it doen'st vent air out, it sucks in it, to release the EGR diaphram. If left undone, you will suck unfiltered air into the vacuum system, eventually leading back into the IM.

 

[Fastest95PGT]

If left undone, you will suck unfiltered air into the vacuum system, eventually leading back into the IM.

Problem? })

 

[RevZempoe]

Yeah that sucks, as I have no filter on my car atm ;p

 

[wpendl1]

Problem? })

Well, if your in a dusty area... eventually it could be problem. If the vacuum line clogs, your egr diaphram will stay open... All the time.
Not to mention, the dirt getting into the combustion chanber will prematurly wear down the piston rings and cylinder walls....

Find a friends car that has a stock filter, any kind of car. Look at the bottom of his filter, and what is inthe stock airbox, that is what will be flowing into your engine.

 

[Fastest95PGT]

Sounds good. Hmm, maybe I should finally put a filter on my 2g's turbo rather than just letting it sit there waiting to suck a Nitrous solenoid in. :urg:

 

[metros]

I would take off the piping leading from your intake (drop in filter, cone, or whatever) and clean all the way to the TB. Your K&N filter is oiled. Sometimes the filters can be overoiled and as the car is breathing in it sucks the oil in onto the sensors causing idling problems. <---my mechanic told me this onetime. I've got a PRM which is oiled and I took off my piping once and could see at the bottom of the tube a substance had collected. Might be worth the 10-15 minutes of work to rule out.

metros

 

[Fastest95PGT]

I have my doubts that an oil filter could possibly be so oiled it would actually suck oil into the engine in anything that would coat the pipes.

 

[wpendl1]

I would take off the piping leading from your intake (drop in filter, cone, or whatever) and clean all the way to the TB. Your K&N filter is oiled. Sometimes the filters can be overoiled and as the car is breathing in it sucks the oil in onto the sensors causing idling problems. <---my mechanic told me this onetime. I've got a PRM which is oiled and I took off my piping once and could see at the bottom of the tube a substance had collected. Might be worth the 10-15 minutes of work to rule out.

metros

I think this can be true for the MAF's. Should not effect the VAF. But, I guess cleaning the intake could not hurt, that's for sure.

Of course an update from the original post generator would help.
Have you checked the vacuume lines? As a last resort, you can check the adjustment of the Idle air screw on top of the throtle body. Big flat blade screw. turn it all the way in, then back it out 1.5 turns. This is a base to start from. From there adjust it up or down to get your idle at the 650 recomended. Make sure after you turn the screw, reve the engine and let it go back to idle. This should be done after doing a proper timming, after checking for any vacuum leakes, and maybe even after adjusting the Throttle Posisioning Sensor.

 

[pktaske]

checking things today...suprisingly, I passed inspection (well, really failed but only beacuse of missing lug nuts).

I will update all soon.