94 XLT NO-START NEED HELP

[Dennis94XLT]

Hi everyone - I sure could use some help with my truck. Here's what is going on.
For past few months, only when restarting engine warm, engine would shake like a spark plug was mis-firing, but it would clear up instantly upon pressing the gas pedal. This has been intermittant - once a week and it always clears up right away when I press the gas pedal the first time. It doesn't come back again until the next time the engine is warm and it's in the mood to shake. I could live with that, but today: Engine warm and it would crank normally but would not start. I tried several times. The engine lights all seemed normal. The gas is 1/2 full - nothing has overheated either and all fluid levels are okay.
I opened the hood and tapped on the idle valve because I had a Sentra that wouldn't start when that went bad years ago - and retried the car - it starts now. I don't know if that was just a coincidence or not - or if the two problems could be from the same problem. Does anyone have suggestions about what to check? I am afraid I will get stranded if I don't get this fixed. The mileage is 80k and I do my own maintenence (which means oil changes, etc). I don't know where the check connector is - or even if getting a tester would reveal an error code with this type of situation or not.
Any suggestions are appreciated very much.
Thank you,
Dennis

 

[Alec]

If you tapped the IAC and that temporarily fixed it, then that is most likely your problem. Either try cleaning it or replace it.

Many people including myself have had problems with the IAC. There are many threads on this problem.

Good luck!

 

[Dennis94XLT]

Thank you for your answer - what does IAC stand for?

Also, do you know if the crank sensor has been much of a problem with these or not?

Dennis

 

[Alec]

idle air control valve.

and yes the crank sensor could be the culprit, but you said that tapping on the IAC worked.

 

[mrboyle]

IAC = Idle Air Control
Crank sensors are not a common failure item, and typically a crank sensor works or it doesn't.

 

[Dennis94XLT]

Thank you all for your answers. I do know what the idle control valve is, but I just wanted clarification since I don't know it by the term IAC.

I read the procedure for cleaning it and the Mass Air Flor sensor. I have one more 3 part question - does anyone know how much it costs to buy a new IAC valve - and if they are available after-market or not - and if after-market versions are any good (if they are available).

Thank you all again!

Dennis

 

[Alec]

I'd just get a new one from Ford for about $70. Torrie at fordpartsnetwork.com may be cheaper.

Good luck!

 

[Dennis94XLT]

Thanks for the suggestion. The local Ford dealer quoted me $116.00 for the IAC valve. The parts on line store is almost half that much. I will use them since I can wait.

Thanks everyone!