Really need some help guys! I have swapped a 305 to 350 TPI, Replaced knock sensor, EST Control module, TPS, IAC, running hooker shortie headers/ y-pipe And Purchased a 350 prom, running accel 24# lbs Inj. Stock Fuel Pump, Bosch plugs/wires Now the Fun stuff... Had the 350 built w comp cam P/N 08-300-8 hydraulic roller. The motor will idle but sometimes either idle's high or starts to drag and then dies if I dont pump the gas, have played with the ilde screw, would set that properly, but the tach is acting up. The tps is set at .63 and have verified at wide open throttle, have set the timing to 0 The tranny has been rebuilt but waiting to be installed. How can I fix the idle, I talked to a speed shop and they said I need a prom burned exactly to my setup? Also any suggestions with the TACH?

 

The TPS should be set at .540.

 

Also, ignition timing should be 6* BTDC with the EST disconnected.

What's your fuel pressure setting? What ECM?

The more info the more likely we can help.

Jake

 

I will get the info on the ecm this afternoon, So I need to reset my timing to 6? Thanks guys, !!!

 

Yes, stock timing for a L98 is 6 degrees BTDC with the EST connector disconnected. You'll have to disconnect the battery for about 30 seconds after making the timing adjustment to clear the stored code that gets set when the ECM detects the engine running with the EST disconnected.

IAC counts should be in the 20-30 count range at idle in Closed Loop.

Check the MAF wires to make sure none is broker.

TPS voltage should be .54 (+/- .075) mV so anything between .615 and .465 is within the correct voltage range.

Adjusting the Minimum Air Control screw on the throttle body will effect the TPS voltage reading. So after establishing the correct idle RPM by using the screw on the throttle body, you'll need to verify the TPS voltage is still within the correct range. A lot of guys set theirs at .610 mv since it tends to give better throttle response at that setting.

Hope this helps.

Jake

 

Jakejr,,, no biggie here but I think its in Volts not mV.

FWIW, I set my TPS to 0.62V at closed idle. And, I have about 20 counts from the IAC at idle.

Also, if there is any surging, look for a vacuum leak.

 

Hey guys,

Got the tranny in the car, ilde is better after setting at 6 *, The car idles good at startup, but then after warming up starts surging and ilding high, Car is driveable but not able to get the ilde down where it needs to be. Thanks for all your help keep them coming