Fired up my 383 stroker build today for the first time. It sounded amazing Quick few details that might help - CC306 cam, ported heads, 58mm BBK tb, AC, AIR, EGR delete.

Having 2 issues though. One is a fuel issue I posted in another thread - I am only getting 15psi at prime, and 25-28 psi at idle. Not sure if that has anything to do with this idle issue, but figured I would mention it.

Now the first time I started the car it idled right at about 900-1000rpm for a few minutes. I shut the car off and started it again a few minutes later. It was idling at about 1500rpm, and would not go any lower. I turned it off, let it cool, started it again, and it was idling at 900rpm but then went back to 1500rpm after a minute or two.

I gave it a few quick revs, and the rpm stay high for a few seconds before they slowly go back down to idle. What could be causing this? I have heard of guys having to drill a hole in the TB blades after cam installs, could that be it?

 

For the idle and the fact you have a 58mm BBk you need to set up the tb and the TPS heres the link http://golenengineservice.com/html/tps.html
Your stroker is going to need more air to breath normal at ldle otherwise the IAC is going to go nuts tring to let air in.
As for the fuel pressure you need to be at around 43. Pull and plug the vac line on the regulator and check it again. after you verify it put the vac line back on. If you don't get 43 at prime and at idle as well as something very close to that while driving you need to fix that before you drive it anymore.

 

Monitor your IAC counts with scanning software.

28psi is WAY too low. Look into that problem ASAP because fuel pressure that low, while enough to let the car run, can cause a dangerous lean condition - bad for a new motor.

 

Fixed the fuel pump and tried the Golen adjustment, and now the car just starts and idles high no matter what (since the blades are tipped slightly). That couldn't have been it. Before I did the adjustment the car started and idled perfectly at 900ish RPM.

It seems like when it warms up, the idle kicks up to around 1500rpm. What could this be? 02 related? Something with the tune?

 

Anyone?

 

LEave the blades closed and drill 2 small 1/8" holes in the blades.

 

High idle is your IAC. Maybe yours is bad? Or a sticky TB maybe?

 

Definitely not a sticky throttle body, think about it. It idles perfectly fine, then when the car warms up it jumps to 1500rpm without me touching the throttle at all.

To me it seems like something is happening when the car enters closed loop... I'll try a different IAC and see if that helps.

 

Also why are the holes different on some TB/IAC? On the BBK on my 93, the hole in the "airfoil" on the tb goes all the way through to the back of the tb into the intake.

On the 58mm BBK I'm selling, the hole in the "airfoil" elbows down right into the IAC with nowhere else to go.

 

Sounds to me like a closed loop issue, as long as the fuel pressure/delivery issue is solved.

 

So I found out the BBK I have on the car ALREADY had two holes drilled in the throttle blades. Those holes were the problem lol! It was getting too much air at idle. I covered both with a piece of electrical tape to test it out and the car idles perfectly now lol.

I ended up leaving one of the holes open, and filling the other hole with high temp RTV. She starts and idles like a champ now, right at 800-900 rpm.

 

Nice. I wouldn't trust the RTV. Time for a new TB.

 

Well now the car is having trouble idling while in gear, since the RPM's drop down a bit. So I have to find a healthy medium between the both holes drilled or maybe just drilling out the IAC hole a bit.