Chevy Astro Bucking Problem

jef1qr

It ONLY bucks when I push the gas pedal down 'slightly'. I can accelerate hard or gradual with no problem.
Only at that certain spot past idle. ( no foot on pedal )

If I hold it at this spot, it will buck and "miss" so bad you think half the cylinders are missing. Get past this spot in pedal position, and it is fine.

Thanks

captaincanada0

I hope someone knows how to fix this cause i have a 1997 and its just started doing the exact same thing! i dont think its a fuel problem cause it works fine when it is floored! and idles so smooth! but just touch the pedal a bit and it runs like crap!

captaincanada0

I fixed mine!!!! ya!!!!! i just put in a new rotor and cap ! but you must take an air hose to the inside of the distibutor! there is little flakes of metal dust in there , thats what made it fun so bad! make sure the drain hole on the bottom of the distributor are clean and clear! mines working fine now for sure!!

buffdizzle

What do you mean by "bucking??" :confuse:

jef1qr

Missing, bad firing.

The problem was I had a cracked coil, which was destroying the dist. cap to soon. Fixed the coil, now runs great.

mxer746

Mine is doing the exact same thing. I also found out that the colder and wetter it is, the worse it is. I've changed the Cap and rotor, plug wires, ignition coil, Mas air flow sensor, intake manifold air temp sensor, and fuel filter.

mxer746

Discovered the problem and how to fix it. Apperhently, when GM made the distrubitors, they didn't heat treat the gear at the bottom right, and the upper bushing is prone to wear. All this allows for slop in the cap between the rotor and the cap contacts, allowing the spark to occ jump to nearest/wrong contact. Especially with moisture in the cap, it's a lot more pronounced. This could explain why I was eating distributor caps, like 3 in 3 months. Replaced the cap and distributor, and went for a 1000 mile trip over the weekend 500 miles of that pulling a motorcycle trailer, with no problems.

dsiever

Hi,

I am having a similar problem with my Safari van. Did you replace the distributor? Was this problem accompanied by starting problem too? My van used to start on the first crank no matter what the weather was like. Now I have to hit it two or three times. Let me know at your earliest convenience. Thanks.

regards,
Doug

captaincanada0

ya im back! you were right! the distibutor wore out! a new cap and rotor helped for a month or 2 but then it starting bucking again! I had to get a new aftermarket distributor now all is better! damn cheap gmc manufacturing! now its up for sale and im going to buy toyota from now on! sorry GM you brought this on! :lemon:

ddreier

Sounds like my 2000 safari.
Did a complete tuneup
But when the weather was wet it would misfire give me a check engine and registar a p300 error code.
When dry out the problem would go away.
No one could correct the problem.
I did notice though that when the problem started that when it was cold and wet that the turn signal switch would also start acting strange.
I noticed that the misfires and the turn signal switch problem occured at the time.
I replaced the turn signal switch.
All my problems went away after almost 2 years of hell when it rained or snowed.

tkuphal

I have a 94 astro w/ same problem. After new wires. plugs, cap, rotor and fuel reg. rebuild it still does it. What fixed it :mad:

tkuphal

Fuel pump fixed it. Bad connection in the tank and a build up metal filings in the motor made it pump under the specs. My distribuator was just fine after 200k and the motor runs and acts like new.