Topic: Choke Tubes Question.

[66RavenGTCoupe]

Having issues with my fresh 289 A code. She runs beautifully in Park but as soon as I put her in reverse or neutral or drive she starts to run really poorly. The C4 has been rebuilt at the same time.  Thinking that it may be a vacuum problem maybe and was wondering if the new choke tubes that I have put in should be sealed where they enter the exhaust manifold heat chamber as I have only pushed them in there. Manifolds have been glass bead blasted and are all clean. I blocked the heat chamber for the choke tubes to prevent any bead getting stuck in the steel mesh filter too. Its an Autolite 4100 carbi by the way. Any other possible suggestions here would be great as this is stopping me from driving her at the moment.
Thanks in advance
- Dan.

[carlite65]

those tubes are a press fit. no sealer needed. check the vacuum line & modulator connections. you could also have a vacuum leak where the choke body bolts to the carb.

[66RavenGTCoupe]

those tubes are a press fit. no sealer needed. check the vacuum line & modulator connections. you could also have a vacuum leak where the choke body bolts to the carb.

The originals were in there fairly snug and the new ones pull in and out with minor force so not sure if this is causing a problem. Thanks for your suggestions. I actually checked vac line and modulator connections last night and made sure the carb was bolted to the inlet manifold snugly too. Will check choke body. Thanks.

[Richard P.]

You didn't mention anything about your carburetor. Has any adjustments been done or made to it?

[66RavenGTCoupe]

Oops! Nope just your standard Autolite 4100 4 barrel.

[CharlesTurner]

Is the timing set new and harmonic balancer rebuilt?

[66RavenGTCoupe]

New points and rotor button. Harmonic balancer would have been done with the rest of the motor I suppose but I'll ask tomorrow. Would that not have caused it to run rough in park also?

[suskeenwiske]

You said that it runs OK in Park but not Neutral. There's no drag against the engine either way, so you may be able to rule out Transmission Drag. It's still odd that Neutral is an issue. For grins, turn off the engine, put it in Drive and see if you can start the Engine; nothing should happen. If it does try to start, then the Neutral Safety Switch is bad. This doesn't necessarily mean that you've found the problem but will need to be addressed. If you can rule out the Safety Switch, I would revisit the Transmission or have whoever rebuilt it take a look.

Try one other thing. Disconnect and plug the small Rubber Tube that attaches to the Modulator Valve. Start the Engine and put it in Neutral and let us know the results.

Ray

[jwc66k]

The choke tube is going to bring in roughly the same amount of air no matter if it's hooked up or disconnected at the choke housing, and the carburetor is set for that amount no matter what.
Do the spray water bottle trick, with the engine running, spray water around the carb base, intake manifold mounting surfaces, vacuum areas. The engine should slow down measurably, or even die when the "spot" is found. Spraying carb cleaner is another trick, the engine will speed up. DON'T SPRAY GASOLINE. It works all too well. Also, inspect the cork seals at the rear of intake manifold to the engine. They're important.
Jim