Dying while idle

[dogfriend]

Low idle speed is a classic IAC symptom- Does the idle pick back up if you (very) gently press the accelerator pedal? If so, you are compensating for an IAC that is sticking closed (not letting enough air in to idle properly)

 

[gavin]

sounds a lot like a bad fuel pump.
again, another problem I had in my Bronco2, lol...
it would run fine, and out of nowhere it start sputtering and die. Sometimes it would start right back up, sometimes I'd hafta let it sit for a couple hours to get it started again.
Finally replaced the in-tank (and inline, which wasn't necessary) pump, and all was good.

 

[gensic11]

is your A/C running while this happens? when my freon was low in my AC the engine would drop RPM's when the compressor would click on and it would almost kill the car, sometimes actually killing it. I got a new compressor and filled my freon and it stopped doing it for a while, but now does it again at idle for me, never really kills the car just drops rpm's real quick every 10 seconds when the compressor tries to kick on.... anyway, try idling with your AC on.. then when it off, see if you notice any difference in the way it idles... this could possibly be the problem..

Josh

 

[diaz]

My friend had the same problem and he addes carb. cleaner. Only problem was that he added pretty much the whole can and his truck wont start. I tried to dry it but dont think i did anything to solve his problem. Any idea what to do so his Ranger cant start up again.

P.S. he put carb. cleaner to clean his throttle body...... i thought thats why they made throttle body claner for a reason.

 

[LindaD]

Well like I said, one shop said it needed a fuel pump, the other said they couldn't find anything wrong after letting it run for hours. This only happens when the temp outside is very very hot. When its below 100 the truck runs great. Yesterday it was 110 out and it dies every time I stopped on the way home. Today it was cloudy and cooler, and it ran fine. The AC don't work, so it has nothing to do with that. Hubby replaced the IAC. It runs fine as long as I am moving down the road, just the idle is when it dies.

 

[dogfriend]

Your symptoms are somewhat similar to what happened when my IAC was sticking: Low idle speed, only a problem when hot, truck stalls when trying to move in gear (because the IAC can't compensate for the extra load on the engine when you shift the transmission into D or R).

From your last response, you said hubby replaced the IAC. Q: Did that have any effect on the problem, or is it too early to tell?

If it didn't fix the problem, the next time the problem happens try this:

In Park, verify that the idle speed is too low (the speed should be about 730 rpm in Park). If the idle speed is too low, carefully and slowly push the throttle pedal down to see if you can get the idle speed back up to about 700-800 rpm steady. You should just need to barely move it. If this brings the idle speed to normal, this suggests that your IAC is sticking closed and not letting enough air in for proper idling. If you have to use a lot of throttle to raise the engine speed, then something else is the problem.

BTW, my opinion is that it isn't that likely to be a fuel pump issue because the flow needed for idle isn't very high. A fuel pump issue would be more likely if you were having problems accelerating or pulling a load.