ttopkindaguy

Hey guys, I'm new to thirdgen.org, and I need some help with my car.

I recently bought a 1987 Trans Am with a 350, carbureted (Quadrajet). Automatic 700r4 tranny with a shift kit.

Here are the problems:

1. When I pull out from a stop sign or light (Whether engine is cold or up to temp, doesn't matter), The car wants to shut off, die. I either have to pull out slow, or, I can hit the gas, get off the gas, and back on and then it will go. It is idling right around 800 rpm.

2. When it is in park, or neutral, and i rev my engine up AT ALL, after i get off, the car drops to really low rpms (300), and then it starts to shake violently.

Please help guys, sorry for the long post

ttopkindaguy

Also, car has like no power. Feels very slow.....

hdavis2005

Have you checked the fuel filter? You may have 2. One underneath the car left side near the rear wheel and one in the carb.

ttopkindaguy

Yeah I have a new one just didn't replace it yet... couldn't find it. But it feels like maybe the float is sticking maybe???

hdavis2005

if float sticks it will be flooding. Changing those filters should be your first step. I have rebuilt a lot of these and trash is a carb's number 1 enemy.

ttopkindaguy

Alright I'll do that when I get a chance. We are getting hit by a hurricane for the next day or 2 lol so it might not get done soon but thanks. Any ideas about the shaking? Same thing?

hdavis2005

I would think so. Change the one at carb first. Is it idleing Rough?

hdavis2005

Be safe in the storm

ttopkindaguy

It all depends. Usually in the morning, a cold start, it won't idle rough. If I start it up in the afternoon, say around 3-4 o'clock, it idles rough until it warms up.
And thanks

afremont

On top of what others said, make sure your distributor isn't loose and able to turn. Check your timing. A bad accelerator pump in the carb could explain why you have trouble accelerating normally, but so could an overall lean condition in the carb or bad timing. What kind of distributor are you running, and does it have a real vacuum advance mechanism?

bestracing

+1

Ozz1967

iTrader: (4)

Unles it's changed, it should be a CC Qjet. However, being an 87, I'm pretty sure those were all fuel injected. In which case, it's not going to be a CCqet, though it might be a vac-advance version.

bestracing

350 motors were TPI only so I'm sure he's either ditched the TPI or swapped a carb'ed 350 into the car.

With aftermarket distributors you can get mechanical advance only. These are mostly for racing where timing advanced during cruise speeds are irrelevant.

Also I have seen people use cc-distributors as on non-ECM motors and wonder why their motor isn't running right. You can't really assume anything over a message board and no offense to the OP, he's just trying to understand the whole situation.

Edwardgp

Accelerator pump in carburetor, fuel filters, tune up??

ttopkindaguy

yes, the motor was swapped from a TPI 305 to a Qjet carbureted 350

naf

iTrader: (7)

Tune up all of your ignition components: replace the plugs, wires, cap and coil if you don't KNOW they're new within the last 5000 miles.

If you've got a distributor without the vacuum advance can on the side, replace it with one that does. See where your base timing at idle is (with vac line disconnected) and verify that the timing advance is working properly. Exactly how much is not as important as making sure that it advances as the throttle is increased and maxes out around 3000 or so rpm.

ONLY after all of the ignition stuff is KNOWN good, start looking at the carburetor. It could likely use a good rebuild. Especially if it's crudded up and no one knows how long since it's been cleaned out real good.

salfirebird92

try changing the distributor cap and coil happen to me before

ttopkindaguy

Is there a specific cap and coil I should get?

Ozz1967

iTrader: (4)

No, but if you can afford to, you might as well go with MSD. I'm assuming you have the "coil-in-cap" style dizzy.

naf

iTrader: (7)

Standard parts store stuff is fine. I'd stay away from Accel though, I've had fitment issues with them where they rocked even after clipped down.

bestracing

I have seen where the center contact button inside the standard parts store dist. have high resistance leading to spark scatter problems at higher rpm's (>3K). MSD has one of the lowest resistance center buttons on the market and I highly recommend using them.

ttopkindaguy

Thanks, all.. One more question. Would anyone be able to tell me the 'part number' or 'code' of the carburetor? It is the stock quadrajet but i don't see a number on it anywhere.

hdavis2005

The carb numbers are stamped on the carb body. Facing carb they are on the right side near the back.

ttopkindaguy

Once again, thanks everyone! The main solution, I figured it out: The catalytic converter was screwed. I cut that off, now it is loud as hell, seeing as it is straight piped, and acceleration is 10000x better.