schecterplayer

Hi everyone. My car is a 92 gt with a trick flow top end kit. Car starts, runs great when cold. But if i turn the car off and re start it after its warmed up, it struggles to stay running. Most times it dies. I have to feather it out to keep it running. Car runs fine after that. History of what ive done. I ran the car at 10º timing to get the top end sorted out. Then i usef my bama tune to get the power out of it. That tune ran really rich. I then disabled the chip and just added timing myself. I kept it at 14 for a while and saw no issues with idle. I tried 16 after a while and thats when i noticrd the idle issue. Ive had no time to play with the timing yet to see what it does. I did do a base idle reset though and that didnt help any. Is the computer bugged out from too much timing? Ive seen many people run 16 just fine

cbdallas

I've had several cars do this in the past, most recently my '05 Sport Trac. My 99 Explorer flatly refused to idle one day, out of the blue. A new IACV might fix it.

MOTORCRAFT CX1824 #E9AZ9F715BA

wbrockstar

(PIP & TFI)
When heat begins to take its tole on these components,they begin causing symptoms like stalling,hard starts,no starts,cutting out between two rpm points,rough idle,etc.They're mounted to the distributor & probably the most well known cause of stalling once operating temp is reached,other than the ect sensor. They'll work fine while the engines cold,but start acting up as soon as the engine reaches operating temp.The tfi module can be tested at Autozone or by using the link below. Heat the module up with a hair dryer before testing it yourself,to create the heat soak condition that causes them to fail.
http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/ignition-control-module-tests-1

(ECT & IAC)
One thing you might wanna check is the ect sensor,since it has a huge influence on fuel & timing and its output signal is used by the ecm to control idle using the iac valve.The ecm begins closing the iac valve as engine/coolant temp rises,so if the ect sensor is out of range,it will directly affect iac valve operation and idle.The ect sensor can be tested by disconnecting its harness then touching multimeter leads to each sensor terminal. Set the meter to read ohms.Test it while the engines cold then warm the engine up and test it hot.The ohms reading should match for the given temp shown.
A ect/act specification chart is posted at the bottom.

(EGR)
When the engine is at operating temp in cruise mode,the egr valve is opened.This is the only mode the egr valve should be open in.When it opens,the ecm leans the fuel mixture & adds timing.This can cause issues when the egr valve is open when its not supposed to be.Example: lets say its open at idle with the engine at operating temp. Youve got base timing set at 16°,then the ecm adds another 10° of advance when the spout plug is in place ( putting it at 26° total ) then the ecm advances it more because the egr valve is open,timing may be advanced too much while the fuel mixture is leaned too much,so stalling could occur.
To rule the egr out as being a possible cause,do this:
Remove the vacuum hose from the egr valve,plug the hose,then take the car for a 15-20 minute test drive (on roads that have stop signs/red lights) to see if the stalling/rough idle condition is still occurring.If the condition is no longer present,trouble shoot the egr system to verify which part is at fault.
Carbon buildup that prevents the egr valve from closing completely or a defective evr solenoid thats supplying vacuum to the egr valve constantly, instead of supplying it during cruise mode only,is usually the cause of the egr valve remaining open when it shouldnt be.

(TPS)
Make sure the tps signal voltage is correct at its closed & wot position,with no voltage spikes or dead spots in between. The tps seems to work best when its set to read .80-.99volts,but any number between .50-1.19volts means its closed throttle voltage is in range.WOT voltage should be 4.84volts or less than Vref voltage,which can be measured at the orange or red tps wire.



​​​​​​​

wbrockstar

Since you made a comment about timing possibly being a trigger for the condition, check the orientation of the distributor/ rotor.
Pull the #1 spark plug,stuff a piece of toilet tissue into the plug hole slightly,mark the 0° & 10° btdc balancer mark with Witeout.Use a tq wrench/breaker bar & socket on the crank bolt and rotate the crank CW until the paper blows out then stop rotation once the 0° mark aligns with the timing pointer.Now remove the distributor cap and look at the rotor.It should be pointed between the two front upper intake bolts,just like shown in the picture below.Its the same direction as the #1 spark plug position on the cap.If the rotor is pointed to the left or right of the direction shown in the picture, the distributor is not indexed correctly and the rotor is off by at least 1 tooth.The engine can still run close to normal,with the rotor off by 1 tooth,but it will cause the issues described in the link below.You might not notice any difference in how it runs when timing is set to 10°,but advancing it more than a few degrees might trigger the driveability condition youre dealing with.
Once you open this link,scroll down to the section thats titled "DONT Install Dizzy 1 tooth/1 plug off" & read.
http://sbftech.com/index.php/topic,119.msg12363.html


Your rotor should point in this direction while the 0° balancer mark is aligned with the timing pointer,if its indexed correctly.