The car is idling high 1500rpm and comes down at about 800 to 1000rpm when warm but surging idle.

Car was always doing the surging and it had a code 36.
Got that taken care of.
After chasing this problem these are things
I've done so far to my car: New Fuel filter, IAC, TPS, FPR, Distributor, cap, rotor, plug wires, spark plugs, MAF, replace gaskets on intake manifold and runners, EGR valve and vacuum lines to make sure that I don't have any vacuum leaks.

After I got all these things done I took the car out for a drive. On take off the car runs good but then it chokes up and on wide open Trottle I can hear the car back firing not sure if it's from the Trottle body or exhaust tail pipe then the car will die.

The car starts up again but not running as it should.

Any tips advice on what could be the problem.

Thanks in advance.

 

 

Why is the aldl in field service mode while timing ?

 

Hi I set the timing 1st without the jumper on A&B on the ALDL.
Then I use the jumper on the ALDL, disconnect the IAC pigtail and tried to set idle @ 450 but car dies at around 900rpm.

 

If iac was commanded in and unplugged. the minimum idle speed gets set. If throttle blades are almost closed you have a vacuum leak or iac is incorrect or not moving all the way in.

 

IAC was commanded by installing the U conductor to A&B on ALDL, turn the ignition to the On position waited 30 seconds to disconnect the pigtail connection to the IAC.
Started the engine and was backing out the Idle screw to lower the RPM to 450 but couldn't achieve that engine will cut of at 900rpm.

I will recheck for vacuum leaks and watch throttle blades to see if they are fully closed.
Can the new MAF be defective and cause high idle too?

 

The engine stalls at 900 rpm
or is just not going below 900 rpm ?

 

It stalls at 900rpm and completely shuts off

 

[QUOTE=Tuned Performance;6523191]If iac was commanded in and unplugged. the minimum idle speed gets set. If throttle blades are almost closed you have a vacuum leak or iac is incorrect or not moving all the way in.[/QUOTE

I was unable to find any major vacuum leaks. There's a small leak on the passenger side valve cover where a hose from the throttle body comes into a rubber grommet..

I suspect the IAC valve to be faulty. I removed it when it was cold and the Pintle is in the same position as when the car was hot.

 

[QUOTE=JuanZ28;6523447]