Crazy idle after 6 bolt swap?

[SexyGsX]

After 6 bolt swap in 2G. Idles irratically, 2000 rpms down to 1000, back to 2000 and it keeps doing it back and forth. I feel it in the brake pedal too. Is there a check valve or something I was suppose to put in the line when I replaced the hose from the brake booster to the intake manifold. It almost dies also when I left off the gas sometimes.
Mods are as follows. Big 16G, K&N FIPK, magnecore wires and NGK plugs. hks boost controller, emission lines removed and blocked EGR. FMIC. Also BBK throttle body and 1G intake manifold. I am just trying to have it run normal. I cant run it hard because of the rebuilt engine, new clutch and flywheel. No boost leaks, I checked. Everything is hooked up fine. I checked, rechecked and rechecked again. Please and thank you in advance.

 

[Pj97GST]

You would be amazed at how helpful the search feature can be...

It took me 15 seconds to come back with these, by doing a simple search for 'idle surge', and rpm fluctuations. This was a completely half-assed search so if you put some decent effort, you will find even more.

http://www.vfaq.com/mods/wayback/BradBauer/engine/surge.html

http://www.dsmtuners.com/forums/showthread.php?t=204712&highlight=Idle+surge
http://www.dsmtuners.com/forums/showthread.php?t=204474&highlight=Idle+surge
http://www.dsmtuners.com/forums/showthread.php?t=203565&highlight=Idle+surge
http://www.dsmtuners.com/forums/showthread.php?t=204796&highlight=Idle+surge

http://www.dsmtuners.com/forums/showthread.php?t=187611&highlight=rpm+fluctuation
http://www.dsmtuners.com/forums/showthread.php?t=91589&highlight=rpm+fluctuation

Link #1 pretty much sums it all up for you on where to start and what to look for exactly.
Follow it, and you should be able to fix your problem.

My solution was to remove anything that even remotely had to deal with idle control, (i.e. fiav, iasc, tb coolant bypass, egr, etc.) Even with all this crap gone, my car idles rock solid @ 750 with 650cc injectors and a TT MKIV pump.

good luck and have fun.

 

[honduraneclipse]

I love it when people blame little problems with their engine swaps. First of when you do a engine swap be prepared to replace everything. I mean everything from your plug wires to the washer on your oil drain plug. Oh yeah and your idle problem might go away if you do a leak down test. And or checking out if that 15-16 year old throttle body you swapped has bad parts such as a ISC, seals, FIAV etc.

 

[91gvr4]

. Also BBK throttle body.

Doubt his 15-16 year old throttle body is the problem

 

[honduraneclipse]

BBK throttle body i will have to look into one of those

 

[mitsuclipsegsx]

Try this!! I had the same problem with it reving high and low, turn your bliss screw all the way in then back out 180 it fixed my problem and cel

 

[SexyGsX]

Fixed the idle problem it was the BBK throttle body. Put my 2G back on with the same sensors that I put on the BBK and now its fine. But now it wont start at all and I think my rear diff is locking up. It has been down about 3 months, about $4000.00 later and now it is still not running. I am tired of this. The more I put into it, the more I get frustrated, broke, and nowhere!

 

[Pj97GST]

Give ya $50 cash for it right now! Aren't DSM's fun bro? What doesn't kill you will only make you broker*



*intentional mis-spell/misuse

 

[f4st]

I used to own a mustang and I went through 2 bbk TBs and had the EXACT problem you were having. As soon as I switched to another manufacturer I never had the problem again.