Hi there. I just insured my '82 Trans-Am, 4 speed, 4 bbl, and now that i'm driving it, it's starting to lurch really bad. When I bought the car the guy who sold it to me told me it was the carb that was screwed, so I rebuilt one and put it on, fuel filter, air cleaner, cap/rotor, set timing etc. It'll run in the garage fine... In fact driving around in 1st gear seems to be fine, but 2nd, 3rd.... it'll lurch really bad if I try and give it any more than a tiny bit of gas. The car was sitting for over a year when I first bought it, and it had about an 1/8th tank of gas, and i've topped it up to 1/3 or so with jerry cans (in the garage..). I don't think it's the fuel system because it seems to be fine in 1st gear.... Any reason why this might start lurching badly in 2nd/3rd gear? Thanks -J

 

You rebuilt the carb - good. When you installed it, did you tune it to the engine? Adjust the float? Secondary AV? Install jets for your engine? Adjust the power valve stop?

 

no, not really.. The carb rebuilt pack had very weak instructions, so I didn't really adjust much internally, (float..), it was a carb straight off an '84 Z-28 though, so I figured it should be good... I have adjusted idle, and i'm trying to adjust fast idle (and the other screw on the passenger side, secondary openings? ) not sure how...

But my main concern is that it's fine in 1st gear, leading me to think that 2nd/3rd gears might be pooched. The guy I bought the car from had a 350 in it (guessing he raced it a bit, since he took the 350 out to put it in his '84 camaro, and was racing that...) I believe this has the 4 speed borg-warner tranny though, (from reading earlier posts), and SHOULD be very strong.
I'm going to check the fluid in that right now, anything I should look for? sludge, metal shavings? Thanks -J
PS. Any help on how to tune the carb would be greatly appreciated, all manuals etc just say to turn the "whatever" screw, not where I can find it....

 

my truck did that same thing when the clutch was almost down to the metal. It would be good in 1st then 2nd it would start slipping on and off. I'm sure that you have experienced a clutch going out though, so I wont question your intellegence.

I'm guessing that when you say " fuel filter, air cleaner, cap/rotor, set timing etc" that "etc" also includes plugs and plug wires?

What RPMS/MPH are you shifting at into 2nd?

Basically as I see it, it wont be anything fuel related because when you shift from 1st into 2nd, 2nd lowers the RPMs, thus needing less fuel.

It could be ignition related if your plug wires were frayed, or your timing is over-advancing electronically (not likely)

Air is probably not a problem either.

So that leaves.... dun dun dun, Drivetrain! I'm sure everything in the motor is sound enough to give you a pleasant ride... so the tranny seems the most likely culprit to me!

BTW, this may seem like a stupid question, but your tires are all filled to spec right? If one is a bit under inflated, while the other side is overinflated, you could get that lurching motion I supposed.

 

ahem, you give me too much credit..
Actually, i'm 20yrs old, this is my second car, first being a Delta88 (FI, auto), so actually no, this is my first experience at driving a standard, MOST of the lugging is my pisspoor shifting, BUT, in the "middle" of a gear should be smooth, and that's when the lugging is, (so that shouldn't be just me..)
but right on, i'll have to check the clutch then, is there an easy way to check it without taking out the tranny itself?

no, actually I did everything BUT the plugs and wires, I pulled a plug and it looked ok, but I will be doing that soon, I just thought this lugging was too harsh to be related to anything but drivetrain ... but hey, who knows..

I can shift into second whenever, only when i'm in second (or third), and try to accelerate under any more than 1/3 throttle or so... if I just gun it, it'll do it harshly... but first gear is eerily good with it....

ahem, and no, the motor is not exactly great, I can hear the lifters ticking.... but that's another matter...
haha, and yea, the tires are all up to level.

I will try the plugs and wires tommorow probably, as well as checking into the clutch... I checked the fluid in the trans and it looked good, (it leaked out of the upper drain plug, and was a nice dark gold.... clean.)
Thanks -J

 

by "in the middle of a gear" you mean when you have your foot down on the clutch, it is lugging? When you are in neutral you have no load on the car... it is just coasting in neutral basically. A free general maintenance that you can do is get a torque wrench and tighten down your driveshaft, tranny mounts, and engine mounts.

There's no way to check your clutch without taking out the tranny (PITA, espescially w/o a lift lol). If you are mechanically inclined, and have an extra 150 to spend, go and get a better clutch anyways, and have your flywheel resurfaced. Your flywheel could also cause this if it was not torqued down correctly.

I'm sure someone else will chime in w/ less drastic measures than dropping the tranny... that is a day project, and I would sure not want to have to do it if I wasnt 100% sure that that was the problem.

 

no, I mean "middle of the gear" foot not on clutch, just slowing accelerating in 2nd gear, say 30km/hr or so... If I try to accelerate at all it'll lug badly, coasting or accelerating SLOWLY is ok. I can accelerate hard in 1st though, no problem...
i'll check the bolts, that's an easy one.... other than that I may take out the tranny, but unless I open it up I won't know very much..... Maybe i'll take it down to tranny shop, if in need....
Thanks -J

 

ahem, well my brother came over today, has driven a few more standards than I have, he can get it to drive a lot nicer than me. And it seems to be going away, maybe it was just bad gas. we topped it off with premium. it seems to be fuel related, i'm just not used to a standard bucking so hard on a missfire...
i'm replacing wires and plugs now, as well as another new fuel filter. we'll see how it goes... -J

 

good luck!

 

Well I put in the fuel filter, plugs and wires. It seems to idle smoother now, but not quite perfect. It'll still lurch if I try and accelerate, unless I do it very slowly... I think I just screwed up the tuning of it when I put it back in (or the lack of tuning...)
I think I may drop it off at a shop on monday and get them to just tune the carb right, if that'll fix it.... -J

 

Please define "lurch" for me. I am thinking that since you can get it run pretty smooth if you really baby the pedal that it is either your clutch being paper thin, or your lifters arent tightened down enough, or are tightened down too much... i think you mentioned something about being able to hear the lifters tapping... I'd adjust valve lash before you send it to your mechanic.

 

Well it lurches like it's missing badly, and because it's a standard, instead of just lacking power, it "lurches".
that's the best I can do.
I thought the lifters on this car were not adjustable? I could check that one... the clutch engages really early, so I think the clutch is fine...
But I think it's the carb because I rebuilt one that was in unknown condition, and bascially took it apart, cleaned it, put it back together, (first attempt at rebuilding a carb.)
Meaning: I didn't tune, or set anything at all. I tuned the idle after it was back on the car. (which is still acting weird, sometimes too high, sometimes too low..)
I may not have mentioned, but when I bought the car, the guy had just put back in the factory motor, after having a 350 in it. So few things were connected. (ie. coolant sensor, any electrical connectors on the carb, O2 sensor, etc... I've replugged all those in, but any others are probably just hanging around...)

also I think the cruise control transducer (or whatever) is seized, the speedo cable was screwed when I got the car, and after putting in a new gear, it only worked for about 5kms... but that's probably not related.

I'll try adjusting some screws on the carb and see if I can get the problem to get a bit better/worse, then see if that could be affecting it.

Just one question: How could the lifters affect that? Could tighenting them affect this?
Thanks -J