couple problems

[supramike7m]

hey guys i searched a bit but didnt find what i was looking for. anyway heres what goin on. when i start my car up it seems to run fine, but when it warms up for several minutes the idle starts goin wak. up and down. and when i have the headlights on i can see them go bright then dim, bright , dim. what do you think?

mods are- intake, 3" turbo back, apexi profec e01, ic/hp, lex afm/ 550's, walbro pump, afpr, safc2(but its unplugged right now).

i was thinking maybe i have a clogged fuel filter, would that cause my idle problem?

 

[robbo185]

if your safc is unplugged it would cause a bad idle due to some of the ecu wires being spliced.

also it could be a tps sensor needing adjustment.

Check your codes and try plugging in the safc and see if that helps

 

[supramike7m]

if your safc is unplugged it would cause a bad idle due to some of the ecu wires being spliced.

also it could be a tps sensor needing adjustment.

Check your codes and try plugging in the safc and see if that helps

ok i plugged it in and nothing has changed, also there are no codes.

 

[AF1JZ]

Alternator maybe? Whatever is causing the drop in idle is what's making your headlights dim.

 

[supramike7m]

shit, good thinking. thats possible. why didnt i even think of that? ill check it out and see.

 

[bigaaron]

Vacuum leak?

 

[supramike7m]

would anything suggested, cause these symptoms only when the car got warm?

 

[bigaaron]

When it's cold the afr is rich because the cold start injector is on.

 

[jetjock]

Err, not to be picky but the cold star injector can only operate when the key is held to start.

 

[jdub]

The cold start injector operates only on engine start...it's power source is the same as power to turn the starter. After engine start, injection by the CSI is terminated. The only way the CSI will still provide fuel is if it is stuck open or has crap in it preventing it from closing. Injector duration is limited by the start injector time switch depending on coolant temp...it's off somewhere between 20-40 deg C.

Edit: JJ beat me to it!


Couple things I would look at:

- Check for air leaks on the vac line after the throttle body
- Check the ISC valve for proper operation.
- Check the TPS for an IDL signal when the throttle body plate is closed
- Check your fuel pressure

 

[bigaaron]

I better roll the diagnostic dice on this one :biglaugh:

 

[jdub]

Everyone should have a set!

 

[bigaaron]

If I didn't say something stupid every few days then you guys would think something is wrong with me.