Pontiac GTO Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
22 Posts
Discussion Starter #1
Help.

I am trying to get my car running right. Took it to a garage to get a tune up because the Rochester that I just put on didn't seem to be working properly. The garage set the timing, added a new pot to the vacuum advance on the distributor and got the choke working properly. The problem is that they idled the car way too high to prevent stalling when it is in gear (automatic). When I got home I re-adjusted the idle set screw to what seemed a more proper RPM and then when putting it into drive the load from the tranny makes it want to stall.

First, I think the carb might be the problem because I haven't been through it and it is a reproduction that I bought. Tomorrow I am going to throw on another carb on the car to see if that makes a difference. They did look at the carb and made some adjustments and set the air/fuel.
The reason I took it in in the first place is that it has a huge bog when you nail the pedal from a dead stop. The car continues to do that even now that it is back from the shop. Their explanation is that the vacuum is to low at idle because of the RAIV cam. I realize that the vacuum is low at idle but there has to be another explanation. They say you have to bring the rpm's up on the engine to create vacuum and then nail it. That takes a lot of fun out of driving the car as it has a 4.33 rear axle and shifts into second gear real quick. Right now it is making very little power initially which isn't right.
I am also wondering if the RAIV automatic cars used a fast idle solenoid which would kick in when the transmission was is gear to compensate for the load? How would that be wired? It would only need to kick in when the car is in gear. I am kind of grasping at straws at this point.
I know that that car should go like a scared cat when I nail it but I am not there yet. Not sure if a solenoid is necessary
Any suggestion or help would be appreciated.
 

·
Premium Member
Joined
·
780 Posts
My suspicion is that with the RAIV cam you need a torque converter with slightly higher stall speed. This would allow the engine to idle without a load on it a and ending the stalling. As to what stall speed you need I suggest you contact one of the companies that make them and get a proper recommendation. I'm starting with Hughes which has a good rep and with Coan which has a real good rep with Pontiac folk. Continental is the best but expensive. To get you started, here's some links:

WELCOME TO HUGHES PERFORMANCE - Hughes Performance

CoanRacing.Com | Race Converters

Torque Converters , CTConverters.com Continental Torque Converters

Hope all this helps in resolving your problems.
 

·
Registered
Joined
·
22 Posts
Discussion Starter #3
Thanks for the reply.
I think you might be right in terms of lightening the load. I had the carb off yesterday and tried an SD carb that I had sitting on the shelf. The car woke right up. The difference was amazing. No more bog and power at both ends of the spectrum. Tried to change the jets and metering rods over to the reproduction quadrajet and it helped but not as good as the SD carb and still bogging initially. After trying all that, I switched everything back to the SD carb and mounted it back onto the car. I did notice a lot of differences between the two carbs and need to talk to an expert about the differences. I have a call into Cliff's for some recommendations.
My next step is to identify what carb they used to build the reproduction and move forward from there. I will also look into the torque converter because I am going to be installing a 200R4 tranny from a GN. I have already purchased the tranny from a guy that was using it in his 69. I will have to ask him if he installed a different converter in it.

Thanks for your help.
 
1 - 3 of 3 Posts
Top