Sometimes tough to start

[jkichline]

I replaced the TPS and cleaned the MAF. Sometimes it takes lots of cranking to start. seems to happen mostly when the engine is warm but it happened yesterday when the engine was cold. Otherwise it runs pretty good. I never replaced the O2's during my last 60K and I'm wondering if this could be the cause.

 

[johndallara]

hard start

Hmmm....

would think that if you can get it to start, then you have +fuel and +spark. Don't think MAF would be an issue. Also even w/ throttle closed --normal-- should start anyway, so doubt TPS. Might be bad IABP valve these are easy to replace and can go bad esp. with intake cleaning.

would also consider something simple like your starter is beginning to go.

also would do a simple check of KOEO and engine-on codes.

 

[jkichline]

I read codes and didn't get anything. I thought TPS because it seems that if I give it full throttle when it happens, it'll start a little easier. Didn't matter because replacing it didn't change anything. What does IABP stand for. I was searching for the part online and couldn't find it.
By the way, the starter seems to be cranking the engine at the same speed it alway has.

 

[johndallara]

hard starting

Idler Air Bypass Valve. also referred to as IAB or ISC (idle speed control). it is the cylinder thing that sits right next to the throttle just next to the intake runners. it feeds air to the engine when the throttle is closed (i.e. foot off gas).

replacement is fairly easy w/ hex wrench -- just don't drop the bolt down into the intake.

I would try this first and see if the problem goes away.

 

[NiNeTy Fo SHO]

If the IAB or sometimes IAC (Idle air control) is the problem, it would not throw a code. A way to test for it is that when your problem occurs (car wont start/hard start), press the gas pedal down a bit to open the butterfly. If it then starts mucho easier, that means the IAB/IAC is not opening to let air into the engine.

 

[NoFlipping]

I had similar symptoms for a while... then my starter died. Replaced it and now all's well. Good luck!