View Full Version : hesitation


stamatisg1977
Oct 19th, 05, 02:50 PM
my car seems to be hesitating all of a sudden. its a 350 w/ m21 4speed
when i start the car i would have to keep revving the engine to get it to finally idle. when i drive and take off the car hesitates and seems i have lost a little power.
could i need a tune up?
thanks for any help
steven

JimM
Oct 19th, 05, 06:48 PM
is it cooling off there like it is here? Do you have a choke on it, does it work? is it adjusted right?

67 Plain Jane
Oct 19th, 05, 07:39 PM
Sounds like the choke is not closing if it does what you're saying when the engine is cold as previously posted.

stamatisg1977
Oct 19th, 05, 08:05 PM
well the weather has been steady. i have an electric choke thats pretty well adjusted. but yesterday and the days before, after i take a short trip around a couple of blocks the car idles strong and consistant at 800rpm. Now it sounds and feels like its stumbling and idling erratically going from 650rpm to 750 rpm. the only thing that i did to the car prior was add a little bit of antifreeze to top it off.

JimM
Oct 19th, 05, 08:15 PM
might want to check that choke, in the morning when it's cold. if you jack the throttle, you should see it snap closed with some authority, and with the key on, it should take a couple minutes to heat up and open. Might just need to lean on the fast idle screw a lil. Since it runs fine warm, I can't see any other possibility. Weathers been steady here, too.... steady 70 during the day, but getting colder and colder everynight.

stamatisg1977
Oct 19th, 05, 08:37 PM
it still stumbles when i accelerate and when its sitting in the driveway all warmed up. the earliest i have ever started the car was from 1:00 in the afternoon.

sc69sam
Oct 19th, 05, 08:55 PM
I would check the accelerator pump. It is a little leaner in the winter so it needs a little extra shot. Maybe just an adjustment or check your fuel filter. Sam

stamatisg1977
Oct 19th, 05, 09:12 PM
i have a clear filter and the fuel sits nice and high at the top. (my filter is vertical running up the front of the engine). also can an overheated spark plug wire cause any concern? i found that two of them were siiting on my headers and were burning hot to the touch

sc69sam
Oct 19th, 05, 09:19 PM
Make sure the wires are not arching on any metal. You can see this especially at nite with the hood open in the dark and running. It may not be your carb. Your wires may be shorting out. :beers:

stamatisg1977
Oct 19th, 05, 09:27 PM
ok thanks i will check the wires tomorrow to see if any wires are melted to the bare wire.
ill check in with results
thanks everyone :thumbsup:
steve

stamatisg1977
Oct 20th, 05, 10:22 AM
started the car the choke plate closed securely, still had trouble keeping it running when i first start it, about 60-65 degrees outside a little chilly, the wires that were on the headers were still ok just a brown burn mark. i went up and down the block a few times and parked it seems to be idling good but te car still hesitates when accelerating. maybe a tune up or does my clutch need adjusting?
i dont know
need some more advice fellas
thanks
steven

tfultz
Oct 20th, 05, 10:32 AM
Replace the EGR Valve and check all the vacuum lines.

My $0.02

stamatisg1977
Oct 20th, 05, 11:19 AM
checked egr valve and vacuum hoses everything seems fine

sc69sam
Oct 20th, 05, 02:37 PM
May just have to rebuild the carb.

BreathWeapon
Oct 21st, 05, 10:25 AM
What kind of carb? I removed the entire choke horn on my Holley, and even in very cold weather (I'm talking -25 C Canadian winters here) I can start the car just fine and it will idle OK once it warms up. I do, however, need to make minor adjustments to idle mixture in the colder months to avoid an off-idle stumble; richen up the little side a bit. It might be worth a shot. Failing that, I would look into ignition timing. You dist might have slipped a bit over time, as they sometimes tend to do.

stamatisg1977
Oct 21st, 05, 11:17 AM
it is a holley 650 double pumper
by the way, is it possible for the wire in the spark plug wires to melt even without damage to the outer jacket?
as stated in previous posts, two of my wires were sitting on the exhaust headers and were very hot t the touch

JimM
Oct 21st, 05, 12:12 PM
Ussualy the wire will show it bad, but I've seen boots that were bad, all you could see when you clean em off good is a tiny black "spot" could happen that way on a wire too, I guess. The "wire" itself is usually fiberglas strands impregnated with carbon, not really a wire (unless they're solid core race wires) it's pretty hard to hurt that stuff, but a hole in the insulation could let the spark arc to any nearby metal. as was suggested previously, fire it up in the dark and look for a light show.

67 Plain Jane
Oct 21st, 05, 04:29 PM
Check the carb and make sure it's not loose also i had a truck once that all of a sudden began falling on it's face from a stop and it turned out to be a piece of the carb to man. gasket was sucked out letting in a lot of air.