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Discussion Starter · #1 ·
Installed my throttle body and am having a problem during cold start. When the motor starts, it goes right to 2,300 RPM and then slowly settles back to normal. Runs great the rest of the time. Anyone else run into this, and if so, how did you fix it?

I would like to straighten it out myself to avoid having to send it back to Mark.
 

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Did you get a tune? Check to make sure accordion/intake is on tight.

Alex
 

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I have had my Shaner TB on for overt wo years without problems and I have not heard of anyone else with his TB that has this problem.

I second the suggestion to carefully check intake fittings...
 

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Discussion Starter · #4 ·
Intake is tight, not sure how that would affect the cold start though. It could effect the way the car runs since the MAF wouldn't see all the flow, but on cold start I'm not sure its a player. The intake opening presented by the throttle plate is larger than the stock unit. I think this may be the issue and then once started the PCM pulls the TB motor back to lower the RPM. Wondering if there is an internal adjustment on the TB for setting the throttle plate position.
 

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The Shanner modification should not cause what you are seeing, his modifications to TB are so minor you can only see the effect on a dyno looking at the Torque curves. If I had to guess I would bet that the electronics that bolt to the TB have an issue. I would remove and re-seat the electronics on the TB, since if this was not positioned right you would have your base TB throttle plate position wrong.

Good Luck :thumb:
 

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An Idle ReLearn can be accomplished either of 2 ways:

1. If immediate computer upgrade is necessary or the car runs rough you need to initiate the 5 minute, stepped procedure.

- A/C OFF, Fans OFF
- Ignition OFF
- Disconnect Battery
- Wait 5 minutes
- ReConnect Battery
- Ignition ON (Do NOT START), wait 1 min.
- START to Idle, Verify A/C & Fans OFF
- Idle to allow H2O to reach 176 degrees
- Idle at H2O at or above 176 degrees for 5 minutes
- Ignition OFF
- Wait 30 seconds
- ReStart and verify smooth idle.

ECM/PCM will contuinue to relaern at a faster rate from a correct baseline. Usually complete in 50 miles.

2. If you are willing to wait for the computer to automatically relearn itself, it will take 100 miles, sometimes 200. You should also vary your driving habits during this time. Complete in 200 miles if no other changes made.

Note: ECM/PCM continues to slowly upgrade to your driving habits continually :cheers:
 

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Discussion Starter · #8 ·
Spoke with Mark Shaner this morning (boy has he got the flu bad!!!!). Apparently, my throttle body is mildly aggressive the way it is ported as a result of some of the porosity that was in the original. He told me when you turn the key, the PCM closes the throttle body plate and then sets it to a predetermined angle for cold start. Since my porting is aggressive, the amount of air would need to be modified with either tuning to alter the startup angle and several other parameters or replace the throttle body. He is going to make me a new one this week and send it out. I will send him mine as he has another customer who has just installed a very large cam and will need a throttle body setup more like the one I currently have. Once I get this cold startup problem resolved, this will be a terrific mod :thumb:

Now if only someone could fix the weather around here, fourth weekend in a row of rain :zboobie:
 

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Mark Shaner is a good guy - I've always heard that.

Good thing you spoke to him.
 
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