low speed drivability (like creeping in traffic).

[PabloX]

I suspect this is just the way these cars ('86 3.2, 75k miles) are, but I'm wondering if there's a way to improve things.

If I'm in first gear, as in a line of cars creeping up to a stop sign or light, and roll on and off the gas, the car bucks something fierce. The only way to drive it smoothly in these cases is to push the clutch in. This coupled with the fact that my first gear synchros are useless makes life difficult. The car also shows the behavior in 2nd gear though it's not as bad and not really an issue.

By contrast, my new daily driver can literally be driven in first gear, with the clutch out, on idle up a hill with no bucking. I fully realize it's not valid to compare cars made 30 years apart from each other, but any words of wisdom are appreciated.

[RedCoupe]

My 86 doesn't act like this. I can creep up to lights with no problem. I would start looking at ignition and fuel systems to see what might be amiss.

[PabloX]

Originally Posted by RedCoupe

My 86 doesn't act like this. I can creep up to lights with no problem. I would start looking at ignition and fuel systems to see what might be amiss.

Good to know it's not normal at least.

I've had the car for 5 years or so and in that time, I've replaced the plugs, wires, cap and rotor. The coil is original as far as I know. However, if it is an ignition problem, wouldn't it generally break down either under hard acceleration and/or damp conditions?

[RedCoupe]

While driving to work this morning, I was thinking about this. I wonder if a sticky ICV could make the engine "hunt"? Also, I know that soft engine and transmission mounts and worn CV joints can amplify bucking or hunting and turn it into a real jerking motion.

[jlex]

I believe it's normal for these 3.2's. My '85 did it and to a lesser extent my '88 does it. On the '85, it was pretty well cured by installing a Steve Wong chip. The idle is set slightly higher if I recall, and I guess the engine management is changed by the chip. Haven't chipped the '88 as it doesn't seem to be as much of a problem as the '85 was although at really slow speeds yeah, it's there...

[kuba_kuba]

Interesting - increased bucking at low speed is the only negative from installing a Steve Wong chip on my '88 (and its not that bad)

[PabloX]

Mine does have a Steve Wong chip installed by the PO. I guess I could put the original chip back in to see what that does.

Speaking of Steve Wong, any idea if he'll update a previously purchased chip? I've considered doing a cat delete.

Also, RedCoupe, as far as the ICV, my car had the problem of the idle bouncing when it's hot. Cleaning the ICV heavily with carb cleaner made this a lot better but didn't seem to do much for the bucking. It does seem like a logical culprit though.

[Smoove1010]

My car did this and also had a flat spot while cruising. I tackled this using all of the troubleshooting steps outlined in the numerous bucking and hunting threads, including checking the O2 sensor, cleaning and checking the ICV, checking for vacuum leaks, re-setting base idle, and checking/adjusting the track/wiper on the AFM. In my case I smoothed it all out when I discovered that a previous wrench had molested the AFM, apparently to lean out the air/fuel mix, probably to pass an emissions test:
AFM Mixture - Am I That Lean?

I can now loaf along at idle in first gear with no bucking, and the flat spot is gone. Acceleration from loafing is smooth and linear with no flat spots. Having said that, dealing with stop-and-go traffic driving a car with a manual trans is still no fun.

Good luck!
GK

[Bleedsblue]

For a car as civilized as a well-sorted 3.2, I think bucking (SW chip or no) is definitely indicative of a minor problem. Pre SW chip and post SW chip, mine never did that--it's a great, smooth "crawler".

I don't know if SW will update a chip for a second owner, but he definitely will (at cost) for an original purchaser of a chip.

[T77911S]

put the original chip back in and then check the AFM.
my brothers had problems like yours and I think that's what fixed his.

[pmax]

Doesn't sound normal.

My 87 drives smoothly at low speeds.

[jlex]

It's not that it's not driving smoothly at slow speeds, it just seems like a bit of bucking at times when going slow in heavy traffic & you let up on the pedal. Feels more like slop in the driveline rather than an engine hesitation problem which is why I was surprised the Steve Wong chip had such a good effect on the '85.

[Pazuzu]

My SC has done it, I thought it was considered uncommon but not rare. There has been discussions of the "bucking bronco" syndrome.

One discussion was the "hanging" drivetrain in relationship to the long throttle rod and/or clutch cable, that you can get a frequency where the drivetrain is actually shaking the rod, which makes the throttle flutter, which makes the drivetrain shake, which is a vicious cycle.

[Bill Douglas]

My SC does it a little too. I just think of it as the car telling me it's not a commuter car, but a car that dreams of wide open spaces (and wide open throttle).

Plus first gear is far too high for crawling along in traffic. Too much riding the clutch and stop and start - Corolla time I call it.

[Tippy]

It bucks because the timing is too advanced. A Steve Wong chip should fix this. I can dial this in easily with my aftermarket EMS MegaSquirt.

Too much timing, buck city. Retard a few degrees, smooth running.

It's been called the "neighborhood creep".

[Frosticles]

My 83 build 3.2 also does this. I was going to have it set up to see if there are any problems.

[Arne2]

I fixed mine by reverting to the stock chip. Much improved low speed driveability.

[aread]

Mine does it a bit (very mild) at really slow speeds, right before you feel like your about to stall. Honestly, I just avoid going that slow... :P

[PabloX]

Originally Posted by Tippy

It bucks because the timing is too advanced. A Steve Wong chip should fix this. I can dial this in easily with my aftermarket EMS MegaSquirt.

Too much timing, buck city. Retard a few degrees, smooth running.

It's been called the "neighborhood creep".

It has a Steve Wong chip in it, and don't most aftermarket chips advance timing anyway?

[DanielDudley]

Your throttle position sensor has two switches in it, one for idle, and one for Wide Open Throttle.

You want that adjusted so that the idle switch is only activated at idle. Once you crack the throttle open, you want that switch off, so the engine can make its own determination of what is happening via the other sensors.