idle problems

[ja950a]

hi guys i have a 89 mustang 5.0 lx. this is my problem the engine will idle fine until the a/c is turned on or steering is turned. Also the engine don't seem to have any crack to it or responce, but it will climb rpm's.It's a fresh stock longblock with aftermarket: headers, h-pipe,catback,and blaster coil. Any help would be appreciated thanks.

 

[HISSIN50]

Retarded timing can cause lackluster performance and a low idle.

Idle assistance under load (for the AC) is achieved with the IAC. Yours might be having issues or dirty.

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[BYRDPE]

yup...verify your timing with a light and the spout out.

 

[ja950a]

thanks for the info.Should I go with the stock timing at 10* btdc because thats where it is now for sure.Also would the iac affect power even with no load from a/c, power steering etc.

 

[ja950a]

I have one other problem the engine don't warm up past about 135* with new 180* thermo,new water pump, and stock radiator.

 

[BYRDPE]

are you verifying the temps with an aftermarket gauge?
as far as timing i would start ~12 and make a couple of wot pulls and listen for detonation. if there is none go to 14 and test.

 

[ja950a]

yes auto meter mechanical

 

[ja950a]

just noticed your from Tn. i'm from huntington tn.

 

[BYRDPE]

just noticed your from Tn. i'm from huntington tn.

yup...howdy neighbor.

 

[HISSIN50]

Yes, the IAC affects the idle even with no ancillary loads on the engine.



Confirm the reading on your aftermarket gauge.

 

[ja950a]

I mean would it effect anything besides the idle quality.

 

[HISSIN50]

I mean would it effect anything besides the idle quality.

Not anything meaningful (it affects idle quality, accomodation of load, and a few little things like dashpot). It has no effect on power.

 

[ja950a]

can the charcoal canister be removed or is it nessesary. I did forget to mention that the car has no cats and no smog pump,also has mallory hyfire 4 ignition box.