dying at idle or during hard breaking

[ryan]

Ok , here's the problem. When I am sitting at a light, the car runs nicely, but every couple of seconds it shakes(pretty big shakes) then will stall. When driving at higher speeds all these problems go away. If I press on my brakes at low speeds the engine will just turn off completely. Kind of an annoying feature to have beacause it constantly makes me have to have one foot on the gas and one foot on the brake while stoppping for fear that it will stall. This problem gets worse as the car warms up.
Where do I start looking?

[johnwaynejeep]

This is a long shot, but I left my car lights on one day and totally killed the battery. I jumped it but had to two foot it because there wasn't enouph juice to keep it running. It was doing the exact same thing. When I stopped it would idle for a second or 2 and then die. When I romped on the brakes it would also die unless I had my foot on the gas to keep it running. Take the jeep into Autozone to have them check the alternator and battery. Like I said it is a long shot and I really don't know what I'm talking about but your symptoms are exactly the same that I had when I killed the battery in my escort.

[ryan]

Thanks for the help jonwaynejeep. I wish it was as simple as that but my battery is brand new and hold its charge.
There are no dimming lights or any signs pointing to an electrical problem. As a matter of fact all the lights on the truck are extremely bright whether the truck is running or not.Do you think it could still be the alternator? If it wasnt charging my battery then theoretically I wouldnt be able to start the truck..
Ryan

[tuck]

you don't mention what motor or transmission, so I presume you're running an automatic. Is it downshifting properly? Does it still do it regardless of being in neutral, drive or 1st?

[JB]

here is another long shot, I had the same symptoms with a crack in the vacume hose going from the master cylinder to the carb.. the bottom of the hose was resting on the steering shaft and it wore a small hole in it .. just enough vacum leak to make it stall out at an idle

[ryan]

tuck- I believe that it is downshifting properly. It is a 727 with a 360 v8. I havent checked if the problem persisits when in neutral or 1st but my guess is that it will still stall out. It stalls out when in park.
JB I'll check that out
thanks guys

[Josh D]

Don't rule out carb float level, clogged fuel filter, dirty idle circuit (carb), or weak fuel pump. The problems sound like fuel delivery to me.

Josh

[trickc]

check the other small stuff first but I'll wager your brake booster diaghragm is shot, with it in park,hit the brakes -does it die? when the booster goes out it creates a massive vaccuum leak . Another thing to try,take the vacuum hose between the manifold and the booster loose,plug it off,now hit the brakes. Still dies? youve eliminated the brake booster,move on. hope this helps.
Curtis

[1Lobo]

Ryan,
This sounds like the same thing that was happening to me. It turns out that my truck had some major vacuum problems, but almost all of them were fixed cheaply.
Check all the vacuum hoses and make sure there aren't any cracks in them (if you haven't done so yet). Replace the hoses with cracks, or, if you aren't sure about the age of the hoses, maybe replace them anyway. Then make sure they are all hooked up correctly. Use a combination of Chilton's and Haynes manuals, plus some diagrams from this website to help you figure it out. One of the next things I would check out is the bolts along the base of the carb to the manifold. On mine, these were really loose. Once I tightened them to correct torque, my truck ran a heckuva lot better. Check out the TVS(CTO) switches and your EGR and then, I think maybe figure out what you're idling at. Mine was way too low (400-500rpm). This also worked miracles. I just had a shop adjust the idle and the mix in the carb and, BAM!!, ran like new and passed smog. I know it's a lot of stuff to look at, but you are saving money(lots of it). The inspector here guessed I had put about $1000 into getting it up to spec--it was more like $200 though tongue.gif . Good luck.

[RichCal]

I vote for a carb problem too. However, it seems like you may have two problems going on at the same time: float AND idle/mixture adjustments. Dying upon braking, hard turning, or severe angles is usually float. Dying at idle is usually idle or mixture adjustments. But whatever it turns out to be - assuming you fix it - let us all know.

[PhilSine]

I'm on the bowl bandwagon too. I just did a carb overhaul & in my tweaking & tuning I experienced the same samptoms as RichCal explained. He talked me through the problem and how to solve it. When I need advice he's the first person I call. He's owned and repaired FSJ's for longer than I've been alive. Did I mention I'm his son?