New 383 stroker with problems

[DowlingMA]

So I fired up my new 383 stroker for the first time yesterday. The car has been sitting with the old motor for nearly 3 years. I have a few kinks to work out that I could use some help with:
1. When I first started it, it idled about 1500 rpm. Now it wants to idle at 0.
2. Driving temp is fine but when I park it the temp climbs. Scary on a new motor. I have yet to notice the fans on but I don't know when they should be.
3. It feels like the motor has excess vibration. I feel the shifter vibrate and the whole car shakes a little, driving or still.
4 Accelerating through low RPMs there is a little bit of valve clatter.

The new motor is a 383 stroker with the LT4 hot cam. I know this is a big and broad list, but this is the biggest project I have ever done on a car and I really feel over my head at this point. I like to learn though. Any assistance is appreciated.

-Mike D

[Craig 94 TA GT]

Do you have access to a scanner? I'd check the computer readings, such as the desired idle, etc.

If you have a stock tune, the temp rising at a stop is perfectly normal. Stock programming sucks for temp, and are set to around 210/230 for primary/secondary fans. You should see it hit about 230, then once the fans cool it down to around 210, they stop and it will cycle to 230 again. Just check to make sure the fans will actually kick on - you can force them on by turning the A/C on.

As far as the vibration, what is your desired idle set to? If you're running that cam, you're going to need it at least 850 RPM. Stock idle is bad for that cam and it will run terrible and shake. I'm not sure if this is the source of your vibration, but mine was really, really bad with a stock idle and stock stall.

For the valve clatter, what lifters do you have? The Comp Cams 850 OEM ones are supposed to be adjusted like stock - 1/2 to 3/4 turn after 0 last. The Comp R's are like barely 1/4 turn from what I heard. What did you set yours to?

[Joe 1320]

What management system? OEM GM? Stock program? What year car?

[ConElite]

We need a little more information on the car? Stock tune? Something to give us an idea of what could be the issue considering me and my brothers last project!

[DowlingMA]

Sorry I did not give enough info. It is a 95 firebird with a T56. No tuning has been done but apparently it needs to be. Is that something I should pursue my self? Is it very difficult?
The Fans cannot be forced on even by the a/c. I do not know how the motor was balanced but my flywheel is the same old one I had. As far as I can tell all plugs and vacuums are hooked up. So I guess the first thing I should pursue would be tuning. Any suggestions on that? Thanks so much.

[Injuneer]

Try these guys for a "mail order" tune. Your build is simple enough that they should be able to get you very close:

http://www.pcmforless.com/

http://www.madz28.com/

Both have good reputations with LT1 tuning.

Stock fan on temps are 226*F for fan low speed, and 235*F for high speed. But they should come on when you turn the AC on. Definitely need a scanner to see what is happening with the idle speed, idle air control motor, coolant temp sensor, etc. - all of which will affect idle speed.

You also need to provide a DETAILED list of the modifiactions. Key would be:
-injector size
-throttle body (stock or aftermarket)
-heads (stock or ported, if ported what kind of flow)
-exhaust system
-any "deletions" like throttle body coolant, EGR, AIR, EVAP, etc.

You are probably aware that there is a "trick" to scanning your 95, since it has an OBD-I PCM and an OBD-II ALDL connector. You need OBD-I scanning software, and either a custom 95 cable, a 12-pin to 16-pin adapter plug, or just use "jumper" wirers as shown on Shoebox's website. If you are not aware of Shoebox's site, take some time to look it over - it is the best source of LT1 data on the I'net, and most of it is based on his 95 LT1.

Shoebox site:
http://shbox.com/1/4th_gen_tech1.html

12-pin -> 16-pin jumpers:
http://shbox.com/1/xraycable.jpg

OBD-I scanning software for LT1:
FreeScan:
http://www.andywhittaker.com/

TTS DataMaster:
http://www.ttspowersystems.com/

EFI-Live V4:
http://www.efilive.com/index.php?opt...mart&Itemid=54

Cable for laptop:
http://www.akmcables.com/

Interpreting scan data:
http://www.injuneer.com/ScanMast.html

[Kevin - Blown 95 TA]

Sorry I did not give enough info. It is a 95 firebird with a T56. No tuning has been done but apparently it needs to be. Is that something I should pursue my self? Is it very difficult?
The Fans cannot be forced on even by the a/c. I do not know how the motor was balanced but my flywheel is the same old one I had. As far as I can tell all plugs and vacuums are hooked up. So I guess the first thing I should pursue would be tuning. Any suggestions on that? Thanks so much.

I think you should verify the balance to make sure they didn't internally balance it, If they did, then the flywheel weight will cause vibration. Internal balance is preferable, but then you need a neutral balanced flywheel.